SPANISH OPTICAL DESIGN MEETING ESODM-2024
Thursday 8 February 2024
INtech La Laguna: IACTEC
Santa Cruz de Tenerife - España
Abstracts
Current and Future NASA Space Telescopes: From James Webb to Nancy Grace Roman and Beyond
Joe Howard
NASA Goddard Space Flight Center
Astronomy is arguably in a golden age, where current and future NASA space telescopes are expected to contribute to this rapid growth in understanding of our universe. A summary of our current space assets will be given, including the James Webb Space Telescope (JWST), our most recent addition. Future telescopes will also be discussed, including the Nancy Grace Roman Space Telescope (RST) and mission concepts for the Habitable Worlds Observatory (HWO) and the Laser Interferometer Space Antenna (LISA), a European Space Agency mission with NASA contributions.
Technology meets application: How optical design plays a key role in connecting
both worlds
Norbert Kerwien
Carl Zeiss, Germany
To create new innovative optical systems, a clear understanding of the underlying application requirements is just as important as having a sound overview of the potential and limits of the involved technologies. The work of optical designers addresses directly this interface. An outstanding or even disruptive design concept gives a surprising answer to previously unmet applicative needs. Therefore, the key role for optical designers is not only to trace rays but to define and shape the entire optical system-architecture based on latest technologies.
This talk will highlight several examples of how new design concepts drove technological development in optics, how new emerging technologies opened the door for new optical system architectures, and how optical design is helping to find the sweet spot that connects both worlds: technology and application.
Compact high-resolution LWIR optical system for the MORERA mission: final configuration
Marta de la Fuente
ASE OPTICS Europe, Barcelona, Spain
The Cubesat-compatible Morera optical instrument is a very compact, low f/n LWIR camera designed to provide high resolution images at farm level to estimate evapotranspiration data and provide personalized irrigation recommendations directly to final users using a mobile device. A SW-defined system will use Big Data to combine all relevant information (AEMET, Copernicus, S-SEBI algorithms) to optimize water resources. The evolution of the objective optical configuration from the initial design is presented.
Review of Stigmatic Optical Systems
Rafael Guillermo Gonzalez Acuña
Huawei technologies, Finland
Recently, the general exact equation to design a stigmatic lens has been found and extensively studied. This equation leads us to explore several stigmatic optical systems. We have noticed that stigmatic optical systems share several properties. In this presentation we review them.
A New Type of Lens for Wide-Angle Imaging in Superior Perspective
Vladan Blahnik
HENSOLDT Optronics, Oberkochen, Germany
Computer scientists surprisingly discovered about a decade ago that a school of Italian landscape painters in the 18th century around Giovanni Paolo Pannini (1691 - 1765) did not paint their paintings in rectilinear perspective, but in an alternative, non-rotationally symmetrical perspective projection. For three-dimensional sceneries, the perspective projection of the Pannini school provides much better images with increasing field of view. Since then, it has been widely used in computer graphics and is commercially implemented in game engines, for example. In the optics community, on the other hand, this alternative perspective projection is unknown.
We present optical designs of imaging systems implementing the Pannini projection. This creates new fields of application for optical systems with free-form surfaces. We also discuss the advantages and disadvantages of realizing perspective projection in hardware, i.e. optical systems, compared to digital post-processing in software, as well as approaches to a digital co-optimization strategy.
Optical Design of HARMONI:
The first light spectrograph for the Extremely Large Telescope
Niranjan Thatte
University of Oxford, UK
The Extremely Large Telescope (ELT) is the world’s largest optical/infrared telescope, with a 39 metre primary mirror. HARMONI is its work-horse, first-light integral field spectrograph that provides simultaneous spectroscopy of approximately 30000 spatial pixels in a 150 x 200 element field of view. It is assisted by adaptive optics (AO) using a combination of laser guide stars and faint natural stars as a reference, or, when available, a single bright natural guide star. By combining the immense light gathering power of the ELT and the exquisite spatial resolution provided by the AO system, HARMONI has the potential to transform the landscape of observational astronomy in the coming decade. Observations of nearby extra-solar planets & extremely distant galaxies, spectroscopy of individual stars in nearby galaxies and spatially resolved studies of objects in our own Solar System are some of the key areas where HARMONI will make a huge impact.
In this talk, I will provide an overview of HARMONI’s scientific capabilities, and provide a detailed walk-through of the instrument’s light path from telescope to detector, including focal plane relay, pre-optics including scale changers and anamorphic magnifiers, image slicers, and spectrographs with a disperser wheel. I will highlight some of the challenges in realising an ELT scale instrument. This work is presented on behalf of the HARMONI Consortium, a collaboration of eight partner institutes in the UK, France, Spain and the USA.
Design Considerations for the Secondary Adaptive Mirror of the
European Solar Telescope
Sergio Bonaque Gonzalez
IAC - TenerifeThe European Solar Telescope (EST) will represent a significant advance in solar physics research. At the heart of this initiative is a specialized component: the Adaptive Secondary Mirror (ASM). While ASMs are already in use in other telescopes, designing one for a solar telescope is fundamentally distinct from its nocturnal counterpart due to the specific requirements of solar observation. The scale of the observed object, the Sun's radiant intensity, rapid fluctuations, and atmospheric influences all necessitate unique considerations. This presentation provides an exploration of the EST's ASM design, revealing its rationale, specifications and technology requirements. In addition, the state-of-the-art technologies that will enable the EST's ASM to become a reality will be discussed. By unraveling the intricacies of these state-of-the-art advancements, our aim is to elucidate the engineering achievements that will enable the EST to expertly counter the changing and demanding conditions of solar observation.
The early development and modern use of the Optical Plate Diagram
Andrew Rakich
Mersene Optical Consulting
New ZealandModern optical designers, empowered by fast computers and excellent optical design software, rarely take the time to consider some of the more elegant analytical approaches to optical design, that were necessary tools in the days when the "brute-force" tracing of millions of rays was impractical. This paper is aimed at convincing optical designers to reconsider the usefulness of one of these approaches.
One of the most powerful analytical tools for assisting “intuitive” optical design is the Optical Plate Diagram (or “SeeSaw” diagram) popularized by C. R. Burch in the 1940’s. This paper goes over Plate Diagram basics, starting with the origin, a 1905 paper by Aldis, with a surprising attribution, and following through with discussions of the work of Burch, Linfoot and Gascoigne. The paper concludes with some modern examples of innovative optical design results that have been enabled by this approach.
Designing metalenses for various length scales: challenges from design to manufacturing
Maryvonne ChalonySynopsys Optical Solutions Group, France
Metalenses pave the way for drastic miniaturization of imaging systems in electric vehicle cameras, smartphones, and other micro-camera applications. As an example, researchers in the U.S. used semiconductor manufacturing techniques to produce a large aperture, flat metalens that was used as the objective lens in a simple telescope. The resolving power of the telescope was superior to what could be achieved with refractive and reflective optics and produced clear images of the surface of the Moon. Although metalenses are a promising technology for scaling down the size of optical systems, they also present challenges in their design and preparation for high-volume manufacturing.
In this presentation, we will introduce design flows and techniques to optimize and simulate metalenses, from an inverse design capability to a ray tracing approach. We will also discuss the impact of manufacturing on metalenses and how optical designers can account for this impact into the metalens design.
Caustics: An old optical theme revived
Sergio Barbero Briones
Instituto de Óptica (CSIC), Madrid, ES
Caustics have a long history in optics, first studied in Renaissance times by Maurolycus. Caustics are the spatial locations exhibiting a higher concentration of light. Within ray optics theory, they are associated with locations where two or more rays intersect. However, not all caustics are equal. Catastrophe theory offers a way to classify the different types of caustics. In recent times, caustics have reemerged as a powerful tool for several inverse optical problems including: 1) non-diffracting beams; 2) wave aberration singular analysis giving rise to multiple hot spots in PSFs; 3) multifocal wavefront design from caustics; or even 4) understanding image formation in transmission electron microscopy. This paper reviews some of them.
Compact and versatile wavefront sensor for current and
emerging challenges in the field
Ricardo Oliva-García*, Carlos Cairós, Juan Trujillo-Sevilla,
José Manuel Rodríguez-Ramos
*Corresponding author: ricardo@wooptix.com
Wooptix S.L., Tenerife, ES
In the last decade, wavefront sensors have broadened their field of application beyond adaptive optics in astronomy to a wide range of disciplines as medicine, biology, or silicon metrology. To make these sensors applicable in these various domains, there is a need to create methods that simplify their use in different settings, eliminating the need for additional calibration or experimental characterization. We have designed a compact sensor, structured as a phase camera, and equipped with an electrically tuneable lens (ETL), to provide fast and accurate defocusing capability. This design is ready to meet the demands of immediate and future wavefront sensor applications. The propagation distance in defocused wavefront sensors is crucial for establishing the dynamic range, accuracy, and frequency space of the measurement. Changes in the optical system (magnifications, resolution, field of view) in this type of sensor involve a recalibration of these distances, generally carried out empirically.
To solve this problem, we have developed a numerical methodology for the adaptation of magnification between different optical systems, such as the change in the objective of a microscope, or the use of different optical relays for magnification changes in macroscopic systems. This numerical tool finds application in mechanical displacement systems, single-shot sensors employing image multiplexing, and sensors featuring an ETL, which is the system we have focused on in this context, and where it is particularly useful, since the maximum range of distances is limited by the characteristics of the tuneable lens. This variable is very important in the design of such sensors, to learn preliminary information about the optimal distance variation for each magnification. This is especially critical when we contemplate the potential real-time application of these devices. Consequently, our tool facilitates instantaneously adjust to magnification levels without necessitating several experimental calibrations.
Poster Abstracts
LIOM: the new IAC-based Laboratory for Innovation in Opto/Mechanics
Nicolas Lodieu & Jeff Kuhn
Instituto de Astrofisica de Canarias (IAC)
Ground-breaking science like the search for life in the atmospheres of extrasolar planets requires extremely large telescopes with diameters of >35m. Emerging technology can build competing and complementary to the large astronomical telescopes being built and designed to achieve some specific science cases such as the detection and study of life-bearing exoplanets in the nearest 100 star systems. In particular, Fizeau optics, non-subtractive shaping of thin mirrors, photonics and neural-network wavefront sensing, active/adaptive optics, integral robotics and tensegrity structures, are key.
A group of scientists and engineers is currently working on the design and construction of a 3.5m precursor telescope, using some of these disruptive technologies. The so-called Small ExoLife Finder (Small-ELF) costs about 5Me and can be finished within the next 5 years to detect nearby large exoplanets. This research and development was recently funded by the European Union to create a new sustainable "Laboratory for Innovation in Optomechanics (LIOM)";
http://research.iac.es/proyecto/LIOM/pages/en/presentation.php) at the Instituto de Astrofisica de Canarias (IAC) led by Professor Jeff Kuhn. LIOM plans for a 50 meter ELF to be built within 10 years for much less than 100 million euros - more than an order of magnitude less than the Keck-era and ELT telescopes. Among its objectives, LIOM aims at developing ultra-thin light mirrors with novel engineered materials including electroactive polymers to reduce the cost and weight of future telescopes. Moreover, LIOM plans to consolidate th know-how for the manufacture of high-quality optics for astrophysics, filters, gratings, and collimators for future telescopes like (Small-)ELF, the European Solar (EST) and New Robotic (NRT) telescopes.
Seamlessly embedded metaoptics and 3D nanophotonics inside crystals:
3D laser nanolithography of enhanced optics for real-world environments
Franzette Paz-Buclatin, Omar De Varona, Leopoldo L. Martin and Airán Ródenas Seguí
Instituto de Astrofisica de Canarias (IAC)
Throughout the last decade we have witnessed the blossoming of new breakthrough concepts within the industry, all based on nanostructuring materials, and which we now take for granted: metalenses, optical 3D nanoprinting, nanophotonic sensors, and even lab-on-fibers. The scientific concepts behind these advances have taken decades to develop across the 80s and 90s in most cases, but the industry adoption of newborn academic ideas and technologies is always slow and measured: a myriad of nanofabrication bottlenecks slows down the adoption of advanced concepts. The concept of nanolithography is currently associated with surface processing techniques inherited from the semiconductor chip industry. The latest advances in lithography are now allowing for the widespread development of the metalens concept. “Old” concepts such as that of photonic bandgap materials (“photonic crystals”) are also now emerging as industrially feasible thanks to decades of research and materials science advancements. A new era of nanostructured optics with advanced properties has now started. However, current nanolithography techniques have a limitation: they are inherently surface processing techniques, incompatible with fabrication inside the volume of transparent optical media. Embedding nanophotonics inside the optical media has two immediate gains: first, the structures are protected; second, architectures can be upgraded for 2 to 3D, this greatly enhancing their potential functionalities.
In this meeting we will present our 3D laser nanolithography technique [1, 2], with a resolution down to 100 nm and footprints on the cm-scale, for the development of 3D nanostructures inside high quality optical crystals such as YAG and sapphire, transparent from the UV to the mid-IR, resistant to extreme environments, and widely used across industries for their optimal physical and chemical properties. We will show how our technique allows for the fabrication of nanophotonic enhanced elements such as: high-efficiency sub-wavelength transmission gratings, nanostructured optical microlenses with bespoke properties, photonic waveguides, photonic crystals, and arbitrary 3D-form interconnection elements for the advanced interconnection of fibers, optics and micro-structures, a feature that is also a key bottleneck in the current race for the development of micro-technologies based on nanophotonics.
IACSAT-1, the first space observatory of the Instituto de Astrofísica de Canarias
Alba Eva Peláez*, Jose Alonso Burgal, Patricia Chinchilla, Carlos Colodro, Xana Delpueyo, Roque Giner, Pablo González de Chaves, Luis Guirado, Alejandro Oscoz, Gara Ramos, David Rodríguez, Jose Carlos Sanluis, Samuel Santana, Ignacio Sidrach-Cardona, Samuel Sordo, Alfonso Ynigo
*Corresponding author: aepelaez@iac.es
InsƟtuto de Astroİsica de Canarias (IAC), C/Vía Láctea, s/n, 38200, La Laguna,
Tenerife, SpainBesides being one of the leading research institutions in Astrophysics in the world, the Instituto de Astrofísica de Canarias (IAC) holds decades of expertise in design and development of astronomical instrumentation, both for ground (OSIRIS in GTC, EXPRESSO in VLT, HARMONI in ELT…) and space observatories (PACS and SPIRE in Herschel, LFI in Planck, NISP in EUCLID…). In recent years it has also been introduced into the field of compact payloads for Earth Observation, with the successful operation of two instruments from space, DRAGO-1 and DRAGO-2. This latter experience has been led by IACTEC-Space, a long-term engineering program within the IAC with the aim of developing high-performance instrumentation on board small satellites. IACSAT-1, the upcoming project of IACTEC-Space, holds a double purpose: creating a synergy between IAC's leading research in Astrophysics and complementing its ground facilities, the observatories of Teide and Roque de los Muchachos. IACSAT-1 will be the first astronomical satellite fully developed at the IAC, with a targeted launch for 2028. The project, which has already undergone the Preliminary Requirements Review, has picked exoplanet research as its main topic.
The main scientific objective of IACSAT-1 will be the confirmation of Earth-like exoplanet candidates orbiting in the habitable zone of cold stars together with other secondary cases including the detection and study of asteroids and near-Earth objects. To fullfil the primary science objective a target of 350 ppm in VIS-NIR for V=13.5 mag stars has been established. In order to achieve this demanding photometric precission several key points must be taken into account in the design: the pointing stability of the platform (currently targeted to be better than 8 arcseconds rms, which represents a challenging figure for a small-sized spacecraft), the extent of the PSF function considering this jitter, and the contribution of straylight to the noise budget, which may require the inclusion of pupil and field masks in the design. In this poster, several optical design trade-offs will be presented taking into account these aspects, as part of the System Requirements Review phase of the instrument.
VINIS, a high-performance optical payload for Earth Observation in VIS-NIR-SWIR
Xana Delpueyo*, Alba Eva Peláez, Jose Alonso Burgal, Patricia Chinchilla, Carlos Colodro, Roque Giner, Pablo González de Chaves, Luis Guirado, Alejandro Oscoz, Gara Ramos, David Rodríguez, Jose Carlos Sanluis, Samuel Santana, Ignacio Sidrach-Cardona, Samuel Sordo, Alfonso Ynigo
*Corresponding author: xana.delpueyo@iac.es
InsƟtuto de Astroİsica de Canarias (IAC), C/Vía Láctea, s/n, 38200, La Laguna,
Tenerife, SpainThe remarkable transformation that the Space sector is undergoing, with a drastic reduction in launch costs and the proliferation of small satellites, calls for the introduction of cutting-edge technologies, particularly in the rapidly emerging Earth Observation market. In this context, the IACTEC-Space group of the Instituto de Astrofísica de Canarias proposes the development of VINIS, a high-resolution optical payload for observing the Earth. This instrument will operate in the visible, near infrared and short-wave infrared (VIS-NIR -SWIR), offering a remarkable Ground Sampling Distance of 5 meters. The introduction of the SWIR wavelength is key in this development, firstly due the lack of solutions that cover this band using small platforms and, secondly, because it provides unique information that cannot be obtained in other ranges. The telescope combines new generation developments and technologies, capable of working in the infrared without the need for cryogenics, with a compact and highperformance optical design, allowing a more efficient, viable and lower-cost alternative to traditional high-resolution payloads.
The primary objective within this project is to reach Phase 1 of the development, i.e., to obtain a first engineering model. The project benefits from the know-how acquired by IACTEC-Space team after the development and successful in-orbit operation of two small cameras also observing in the SWIR range with uncooled detectors. VINIS boasts several other key design features that contribute to its cost-effective solution. These include a two-mirror optical design employing metallic optics, an optomechanical concept that ensures athermalization, and the adoption of cutting-edge manufacturing tolerances that expedite the integration process. Additionally, VINIS makes use of a single extended InGaAs detector capable of covering the entire observation range. In this poster, further details into the design will be presented, and also the first results of the AIV of the instrument’s prototype model.
CSOA: How to Transform an Optical Design into a Manufacturable Optical System
Verónica Canto-Caño*, Marta Escriche-Velilla, Ana Fragoso-López, Maider Insausti-Martínez, Félix Gracia-Témich, Ana M. Marcos-Martin, Marta Puga-Antolín, José Luis Rasilla-Piñero
*Corresponding author: veronica.canto@iac.es
CSOA Project, Instituto de Astrofísica de Canarias, Santa Cruz de Tenerife, Spain
The Advanced Optical Systems Centre (CSOA) is a project of the Instituto de Astrofísica de Canarias, which objective is to create a production centre of optics for astrophysics, and in particular case, we are going to talk about the manufacture of the New Robotic Telescope (NRT) mirrors. With this poster, I will try to explain which are the essential steps to achieve the fabrication of an optical element designed with technical software such as Zemax OpticStudio or Code V. Firstly, I am going to do a brief introduction to NRT’s optical design focusing on the tolerance analysis. Then, I am going to explain the different fabrication process with the CSOA’s machines for each element.
Optical metrology in the fabrication process
Ana Maria Marcos*
*Corresponding author: ana.marcos@iac.es
Instituto de Astrofísica de Canarias, Santa Cruz de Tenerife, Spain
The development of the new Advanced Optical Systems Centre (CSOA) in the Institute of Astrophysic of the Canary Islands, has pushed the institute to go into the field of optical fabriaction. Currenly, the institute is equiped with the latest technology machines for this purpose. Hence, the CSOA is able to achieve the complete fabrication process of optical surfaces needed for optical designs of telescopes and astrophysic instrumentation by the IAC proyects. In manufacturing processes optical metrology is essential. Each step in the fabrication requires a specific metrology technique to evaluate the surface quality, and for this, different equipment is needed. The CSOA has currently a variety of metrology equipment, since a 3D scanner for the initial steps to high precission interferometers for the final testing. In this poster, all the metrology processes asociated to optical manufacturing carry on in CSOA is going to be explained.
Optical upgrades of the Gregor Infrared Spectrograph
Silvia Regalado Olivares, Roberto López López, Francisco González,
Manuel Collados Vera, Carlos Quintero Noda, Jorge Quintero Nehrkorn,
Horacio Rodriguez Delgado, Ángel Mato Martinez, Claudia Ruiz, Jonai Bienes
*Corresponding author: Silvia.Regalado@iac.es
Instituto de Astrofísica de Canarias, Santa Cruz de Tenerife, Spain
The GREGOR Infrared Spectrograph (GRIS) can perform spectropolarimetric observations in the spectral band between 1-2.2 μm. The spectrograph has a Czerny-Turner design and has allowed the operation in the traditional long-slit mode since 2014. Later on, in 2018, it was upgraded with an Integral Field Unit (IFU) based on an image slicer. The latter option makes GRIS a unique instrument that, after more than 8 years of operation, is still at the forefront of solar physics, particularly in the infrared. A third upgrade took place in 2021, where optomechanical, control, and software improvements have been conducted to introduce a new spectral channel that receives light below 900 nm. This new spectral channel allows simultaneous observations with the previous infrared camera. Additional improvements include adding a new diffraction grating with a different order separation to maximize the combination of spectral bands of interest between both. The feasibility of operating both cameras simultaneously, and synchronized with the polarisation modulation package, has been already tested. Moreover, future upgrades are being prepared, such as including a third channel for the 656 nm and 770 nm that will allow observations at three different wavelengths simultaneously and installing two more IFUs: one with a 70-μm slicer mirror (already manufactured and being tested) and the last with a 35-μm slicer mirror (in development).
This work is a full compilation of all the optical upgrades that have been made in the past and those that are yet to come.
HARMONI at ELT: Opto-mechanics of the Pre-optics at CDR
Instituto de Astrofísica de Canarias (IAC)Alberto Hernández González*,a, Elvio Hernándezaa, Ángel Alonsoaa,
Begoña García-Lorenzoa,b, Niranjan Thattec
on behalf of the HARMONI consortium
*Corresponding author: alberto.hernandez.gonzalez@iac.es
a Instituto de Astrofísica de Canarias (IAC)
b Astrofísica, Universidad de La Laguna (ULL)
c Oxford University, U.K.HARMONI is the first light visible and near-IR integral field spectrograph for the Extremely Large Telescope (ELT). The IFS Pre-optics (IPO) is one of the HARMONI sub-systems. It receives the re-imaged telescope light from the Natural Guide Star Sensor or receive light from the calibration sub-system.
The primary function of the IPO is to reformat the field for the selected spatial scales and to deliver the field at the input of the Integral Field Unit (IFU). The IPO supports four spaxel scales and also provides components to check the alignment of the telescope and instrument pupil alignment during integration. The Pre-Optics contains 30 opto-mechanical mounts working at cryogenic temperatures and classified into three types depending on the mirror shape.
In this poster, the various opto-mechanical mounts used in this subsystem, categorized by the mirrors they are designed to support will be explained. Additionally, an update on the current test status and future testing plans for these mounts, addressing the challenges posed by stringent environmental requirements will be provided.
The European Solar Telescope: Optical and Opto-mechanical design and analysis at the Preliminary Design Phase
Marta Belio-Asin*1, Juan Cozar-Castellano1, Mahy Soler1, Jorge Sánchez-Capuchino1, Sergio Bonaque1, Noelia Feijoo1, Angel Mato1, Miguel Núñez1, Claudia Ruiz1, Mary Barreto1, Manuel Collados1,2
*Corresponding author: marta.belio@iac.es
1 Instituto de Astrofísica de Canarias (IAC)
2 Departamento de Astrofísica, Universidad de La Laguna (ULL)
The European Solar Telescope (EST) will be part of the next generation of ground-based solar telescopes. With a primary mirror of 4.2 meters, it will be the largest solar telescope ever built in Europe offering a large collecting area and extremely sharp images, due to the MCAO system integrated within the optical path to compensate for atmospheric turbulence.
This poster outlines the optical design of EST at the Preliminary Design phase, from the primary mirror to the science instrumentation, the opto-mechanical design and the workflow to consolidate the model, as well as the feasibility of the envelopes. Finally, the expected performance delivered by the telescope will be shown.
MEARTE: Mini Espectrógrafo de Alta Resolución Tipo Echelle
(Mini Echelle Type High Resolution Spectrograph)
Félix Gracia Témich*
*Corresponding author felix.gracia@iac.es
Instituto de Astrofísica de Canarias, Santa Cruz de Tenerife, Spain
The design, fabrication and testing of a low cost echelle type spectrograph that can be replicated by anyone by just getting the materials, being all of them easily accessible, is presented. This spectrograph achieves resolutions between 7000 and 9000 (depending on the combination of camera and slit). This makes it a useful tool in astrophysics for a variety of applications such as the identification of chemical elements in stellar objects like stars, quasars, galaxies or measurement of rotation or radial velocities to mention a few. Initially this spectrograph is intended for amateur astro spectroscopy, but considering that large telescopes are currently performing spectroscopy by selecting small regions of interest with similar instruments, this could be another option.
The development of the new Advanced Optical Systems Centre (CSOA) in the Institute of Astrophysic of the Canary Islands, has pushed the institute to go into the field of optical fabriaction. Currenly, the institute is equiped with the latest technology machines for this purpose. Hence, the CSOA is able to achieve the complete fabrication process of optical surfaces needed for optical designs of telescopes and astrophysic instrumentation by the IAC proyects. In manufacturing processes optical metrology is essential. Each step in the fabrication requires a specific metrology technique to evaluate the surface quality, and for this, different equipment is needed. The CSOA has currently a variety of metrology equipment, since a 3D scanner for the initial steps to high precission interferometers for the final testing. In this poster, all the metrology processes asociated to optical manufacturing carry on in CSOA is going to be explained.
EST Heat Rejecter, a Cooled Mirror Preliminary Design
J. Cozar-Castellano1*, M. Belío-Asín1, M. Núñez Cagigal1, M. Soler1, A. Mato1, M. Barreto1, M. Collados1,2, C. Padilla-Hernández1, J. Sánchez-Capuchino1, N. Vega1, I. Funes3, A. García-Hidalgo3, A. Gómez3, J M. González3, H. Lacasta3, C. Fernadez3, M. García-Cosío3
*Corresponding author: juancc@iac.es
1 Instituto de Astrofísica de Canarias (IAC)
2 Departamento de Astrofísica, Universidad de La Laguna (ULL)
3 CITD, 28906, Getafe, Madrid, SpainDescribed is the preliminary design of the EST Heat Rejecter, which is a cooled mirror with a central hole located at the prime focus of the telescope to reject solar radiation out of the science field of view.
The challenges presented in the design of the Heat Rejecter are the small envelope available for the thermal control system and the heat power to dissipate. The surface temperature of the mirror shall maintain a temperature deviation to ambient air within +/- 3 ºC during observation. A thermal prototype has been developed to check the key requirements for the correct operation of the Heat Rejecter. This prototype has been manufactured in copper by additive manufacturing.
Another key component of the HR is the pointing system, which will collect the energy scattered on the HR mirror to determine the location of the sun disk.
Optical design of a two-mirror freeform telescope inside INTA
SmallSat constellation program
Andrea García Moreno*, Rafael García López , David Escribano Lahera,
Carmen Vázquez Pérez , Marianela Fernández Rodríguez,
Luis M. González Fernández , Tomás Belenguer Dávila
*Corresponding author garciamoa@inta.es
Departamento de Óptica Espacial, Instituto Nacional de Técnica Aeroespacial (INTA),
Ctra. de Ajalvir, km 4, 28850, Torrejón de Ardoz (Madrid)
ANSER is the first mission of INTA SmallSat constellation program. Its main objective is the study of inland waters quality. This mission is composed of a cluster of three satellites flying in formation, 1 leader and 2 followers. Each satellite is composed by 3U of CubeSat and the full payload must fit in 1U. The main payload of the mission, the one onboard in both followers, consists of a two-mirror freeform telescope with two micro spectrometers at the image plane. The secondary mirror of the telescope has a freeform component described by the astigmatism Zernike polynomial Z5 to generate a binodal astigmatism distribution at the image plane and obtain high optical quality at the entrance of both micro spectrometers.
Optical design of compact high-resolution spectrometers inside
INTA SmallSat constellation program
Carmen Vázquez Pérez*, Andrea García Moreno, Marianela Fernández Rodríguez, Luis M. González Fernández, Tomás Belenguer Dávila
*Corresponding author cvazper@inta.es
Departamento de Óptica Espacial, Instituto Nacional de Técnica Aeroespacial (INTA),
Ctra. de Ajalvir, km 4, 28850, Torrejón de Ardoz (Madrid)
ANSER AT is the second mission of INTA SmallSat constellation program. Its main objective is the study and monitoring of greenhouse gases, air quality and polar ozone by absorption spectroscopy. It is composed of a cluster of four CubeSats flying in formation, each of them comprised of 6U. The main payload of each CubeSat consists of a catadioptric telescope (1U) and a refractive spectrometer (2U) each of them working in a different spectral range: UV, Vis, nIR and SWIR. The optical design of the spectrometer, which spectrally disperses and analyses the energy collected by the telescope, is based on a reflective diffraction grating with a slit at the entrance.
How to build an adaptative mechanical model from the
optical design of a cryogenic instrument
Elvio Hernández*
*Corresponding author elvio.hdez@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
It is shown how to make a mechanical model of a cryogenic instrument that regenerates itself every time the optical design changes, going through the key points and presenting the case study of the HARMONI (the first light integral field spectrograph for the Extremely Large Telescope) Pre-Optics model.
The calibration module delivers a source to test and calibrate the system in the laboratory. The LWS dichroic delivers the 589nm line of the dowstream beam coming from the mesosphere to the dedicated LGS WFS for sensing the beam coming from the artificial star, whereas 470nm-900nm range is transmitted to the GTCAO natural guide star (NGS) low order WFS, LOWFS. This contribution describes the optical design of the three subsystems.
Optical design of the GTCAO LGS WFS
Marta Puga Antolín*
*Corresponding author marta.puga.antolin@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
LWS is the wavefront sensor for the artificial laser guide star (LGS) for GTCAO, the adaptive optics system for GTC. It comprises the wavefront sensor module, the LGS Calibration module and the LWS dichroic. The sensor is based on a Shack Hartmann model and counts on an OCAM2 camera allowing it to sense the artificial star at distances ranging from 80 to 200km.
The LGS calibration module delivers a source to test and calibrate the system in the laboratory. The LWS dichroic delivers the 589nm line of the dowstream beam coming from the mesosphere to the dedicated LGS WFS for sensing the beam coming from the artificial star, whereas the 470nm-900nm range is transmitted to the GTCAO natural guide star (NGS) low order WFS, LOWFS. This contribution describes the optical design of the three subsystems.
Design and fabrication of a novel phase mask to inscribe
fiber Bragg gratings for astronomical applications
Xijie Luo*
*Corresponding author: xluo@aip.de
In this paper, we provide a comprehensive analysis of Fiber Bragg gratings (FBGs) fabricated using an aperiodic phase mask technique. Employing the rigorous coupled wave analysis (RCWA) method, we accurately compute the interference pattern formed behind the phase mask, allowing us to determine the refractive index pattern at the fiber core. Utilizing the transfer matrix method, we derive the reflection spectrum of the FBG. Our approach involves dividing the phase mask into five segments, each generating a reflective filter for the designed Bragg wavelength. Our focus centers on exploring the influence of different designs in the overlap region of the phase mask, thereby affecting the FBG reflection spectrum. This study contributes to the development of aperiodic FBGs with customized spectral characteristics, showcasing the potential for advanced applications in filtering out the OH emission for ground based observations.
Active primary mirror for the European Solar Telescope
Angel Mato*
*Corresponding author: amm@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
The European Solar Telescope (EST) is a 4-m class solar telescope. It will work in open dome configuration, so gravity, wind and thermal loads over the entire telescope are critical issues. The EST M1 Assembly will have to cope with them while ensuring an excellent optical surface shape.
The preliminary design of the EST M1 Assembly was finished in 2022. This poster presents the main requirements, the main subsystems and the expected optical performance of this system, with special emphasis on the active optics capabilities.
Local seeing from CFD simulations at the European Solar Telescope
M. Solera* and K. Vogiatzisa
*Corresponding author: mahy.soler@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
Seeing is one of the main effects that determine the optical quality of an observation and plays a crucial role in the preliminary design of the European Solar Telescope (EST). EST will be located at the Observatorio del Roque de los Muchachos. The telescope structure will be on top of a 35 metres pier. The enclosure will be retractable, exposing the telescope to the ambient air, thus, increasing the natural air flushing. Computational fluid dynamics (CFD) has been proven as a powerful tool for modelling the flow behaviour around modern large telescopes. The present study uses CFD simulations to estimate the aerothermal behaviour and local seeing of the European Solar Telescope under different environmental conditions. This model includes the site topography, the nearby telescopes and the EST. The CFD simulations include the predominant wind directions at the site and the median wind speed. Transient simulations using Improved Delayed Detached Eddy Simulation (IDDES) were run to estimate temperatures inside the optical volume. State-of-the-art approximations for seeing estimation from CFD data have been used in a post-processor tool.
Beam Metrology prototype to control industrial Direct Laser Interference Patterning (DLIP) texturing processes
Zaira M. Berdiñas*, Clovis Alleaume, Camilo Prieto
*Corresponding author: zaira.modrono@aimen.es
AIMEN Technology Center, O Porriño, Spain
In this work, we present a Beam Metrology optical system to monitor in real time an industrial laser manufacturing process that texturizes samples based on the Direct Laser Interference Patterning (DLIP) principle. Interference patterns are obtained by splitting a coherent laser beam into two or more beams, which are later overlapped on a workpiece using a robot. DLIP technology allows structuring sub-micron scale textures on materials surfaces that modify materials functionalization properties, such as iridescence or hydrophobicity. Our optical design diverts a small percentage of light from the main industrial processing path to provide: i) an image of the interference pattern at the focus plane, and ii) an image of the texture being imprinted. Key indicators are later extracted from these two images to feed back and recalibrate the robot movement in real time. This poster presents the beam metrology system, from the optical design to the first prototype developed in our facilities. The work is being developed at AIMEN as part of OPeraTIC, a Horizon Europe project, aiming at pushing forward the state-of-the-art by high-speed periodic structuring not only flat or simple geometries but also more challenging 3D samples.
INTEGRATION AND OPTICAL ALIGNMENT OF THE MCAO TESTBED FOR THE EST
Noelia Feijoo*
*Corresponding author: noelia.feijoo@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
The European Solar Telescope is a 4.2-m telescope whose main objective is to shed light on the roots of the magnetic processes taking place in the solar atmosphere. With this goal, the telescope will perform simultaneous spectro-polarimetric measurements in multiple spectral lines thanks to the Science Instrumentation Suite (SIS) with which it will be equipped. A Coudé Light Distribution (CLD) is being designed to provide each instrument with a high-quality coudé focus and a location within the rooms. The CLD consists of a series of fixed and exchangeable beam splitters, mirrors and compensators to give the instruments great flexibility for observation modes. The design is made according to throughput and optical quality requirements, in which the control of astigmatism and polarisation induced by the optical elements is of high relevance. This contribution presents the preliminary design of the CLD that should meet the proposed telescope and instrument requirements.
OVERVIEW AND PRELIMINARY DESIGN OF THE COUDÉ
LIGHT DISTRIBUTION FOR THE EST
Noelia Feijoo*
*Corresponding author: noelia.feijoo@iac.es
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
The European Solar Telescope (EST) is a 4-meter solar telescope that works in a wide spectral range and has a 135’’ circular Field of View (FoV). It will be equipped with an innovative AO system integrated into its optical path to provide a high resolution in 60‘’ FoV. With the aim of implementing the best sensing and wavefront correction strategy on the telescope, a testbed of the Multi-Conjugate Adaptive Optics (MCAO) prototype has been developed. The testbed consists of an illumination system with point-like and extended source capability coupled with a configurable turbulence simulator, a set of 3 Deformable Mirrors (DMs), three Shack-Hartmann Wavefront Sensors and a science detector. Different lower-complexity AO configurations are being tested before the implementation of MCAO. This contribution describes the integration and optical alignment procedure of each subsystem and the AO configurations studied.
Design, manufacture, and characterization of reflective diffraction gratings
operating at the terahertz range for space applications
García-Lozano, Gonzalo1*; Mercant, Guillermo1; Fernández, Marianela1; Torquemada, M. Carmen1; González, Luis Miguel1; Belenguer, Tomás1; Cuadrado, Alexander2; Sánchez-Brea, Luis Miguel3; Alda, Javier3
*Corresponding author: ggarloz@inta.es
1 Instituto Nacional de Técnica Aeroespacial (INTA), Madrid
2 Universidad Rey Juan Carlos, Madrid
3 Universidad Complutense de Madrid, MadridThe efficient detection of electromagnetic radiation in the terahertz (THz) range represents a significant barrier to overcome in space exploration. A future observatory would be a large telescope with a far-infrared spectrometer included among its instruments. The spectrometer heart will be a diffraction grating capable of withstanding the demanding conditions of space.
This contribution describes the design, manufacture, and characterization of aluminium diffraction gratings. The experimental setup includes a THz quantum cascade laser source, an off-axis parabolic mirror, and a radiation detector to verify the correct operation of the gratings, diffracting the THz radiation at the predicted angle.
Compacted Raman-Libs optical head design for the PHOENIX project
M. Sanz-Palomino*, I. Muñoz, T.Belenguer, A.G. Moral, P. Rodriguez Perez
*Corresponding author: sanzpm@inta.es
Instituto Nacional de Técnica Aeroespacial (INTA),
Ctra de Ajalvir, Km 4, 28850, Torrejgón de Ardoz, Spain
The combined Raman-LIBS spectrometer for the PHOENIX (Portable Handheld cOmbinEd RamaN-LIBS-XRF) project, funded by the European Space Agency (ESA) for the PANGAEA programme, is an instrument developed by INTA. The prototype meets the requirement of incorporating in a single instrument three optical channels (Raman, LIBS and inspection camera) which share the main optical path of the instrument, along with the compactness of the instrument itself, being able the prototype to be carried by an ESA astronaut in its training in the next ESA Pangaea field campaigns.
Use of plenoptic wavefront sensor in a laser communication link between
La Palma and Tenerife under strong atmospheric turbulence
Luis Fernando Rodríguez Ramos1*Jorge Socas Negrín1 Joan Torras Estruch1 Pablo López Díaz1 Noelia Martínez Rey2
*Corresponding author:
1 Instituto de Astrofísica de Canarias (IAC)
2 Australian National University (ANU)During September ’23, the Free Space Optical Communications (FSOC) group of the IAC, carried out a series of optical links between the Jacobus Kapteyn Telescope building, in the Roque de los Muchachos Observatory, and the ESA Optical Ground Station (Teide’s Observatory). In this 144 km range horizontal optical link, the FSOC group had the chance to use for the first time a plenoptic wavefront sensor together with a coherent source - a 8W laser with a wavelength of 1590 nm - under strong atmospheric turbulence. The analysis of the collected data permits to estimate the suitability to use a plenoptic wavefront sensor in laser communications and to characterize the atmospheric properties of the seeing and the horizontal turbulence. The poster will show the optical parameters and the setting up of the systems used in the transmitter part in La Palma, as well as the receiver part in Tenerife, with emphasis on the design of the plenoptic wavefront sensor.
Dynamic Analysis for Modelling and Control of the Primary Mirror
Actuation System of EST
Miguel Domínguez, Jose Gonzalez, Juan Albino
*Corresponding author:
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
The European Solar Telescope (EST) M1 primary mirror's active optics system offers two control approaches for the actuation system, which will handle over two tons. By manipulating 80 actuators, we can modify the mirror's surface either by positional or force commands. This coordinated effort improves image quality against external factors like gravity and temperature fluctuations.
The study unfolded in two stages, relevant for both actuator modes. Initial tests identified dynamic responses and non-linearities stemming from saturations pre-command. Subsequently, we developed models replicating the system's response, validating results. Once we confirmed effective representation, saturation blocks and output feedback were added, fully modelling the actuator prototype. This research enhances understanding of the dynamic behaviour and control methods for EST's primary mirror actuation, vital for superior solar observations.
Harmoni preoptics design at FDR
Miguel Angel Cagigas Garcia*
*Corresponding author:
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450nm to 2450nm with resolving powers from 3500 to 18000 and spatial sampling from 60mas to 4mas. It will use an image slicer to provide spectra over a single contiguous area, providing fields of view on the sky of 9.3x6.3”, 4.2x3.1”, 2.1x1.5” and 0.84x0.62” with increasing spatial resolution (i.e.- 60x30, 20x20, 10x10 and 4x4 mas2) and magnification 2, 3/6, 6/12 and 15/30 respectively.
The pre-optics subsystem take light entering the science cryostat (from the telescope or calibration system), reformatting and conditioning to be suitable for input for the rest of the instrument. This involves many functions, mainly relaying the light from the telescope focal plane to the integral field unit (IFU) focal plane via a set of interchangeable scale changing optics. The pre-optics also provides components including a focal plane mask wheel, cold pupil masks, spectral order sorting filters, a fast shutter, and a pupil imaging capability to check telescope/instrument pupil alignment.
We present the optical design of the HARMONI pre-optics for the Final Design Review and, in particular, detail the differences with the previous design and the difficulties overcome.
Dynamic Analysis for Modelling and Control of
the Primary Mirror Actuation System of EST
Miguel Domínguez*, Jose Gonzalez, Juan Albino
*Corresponding author:
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
The European Solar Telescope (EST) M1 primary mirror's active optics system offers two control approaches for the actuation system, which will handle over 2 tons. By manipulating 80 actuators, we can modify the mirror's surface either by positional or force commands. This coordinated effort improves image quality against external factors like gravity and temperature fluctuations.
The study unfolded in two stages, relevant for both actuator modes. Initial tests identified dynamic responses and non-linearities stemming from saturations pre-command. Subsequently, we developed models replicating the system's response, validating results. Once we confirmed effective representation, saturation blocks and output feedback were added, fully modelling the actuator prototype. This research enhances understanding of the dynamic behaviour and control methods for EST's primary mirror actuation, vital for superior solar observations.
HARMONI at ELT: Opto-mechanics and mechanism prototypes
Alejandro Luján González1*, Elvio Hernández1, Ángel Alonso1, Begoña García-Lorenzo1,2, Niranjan Thatte3 on behalf of the HARMONI consortium
*Corresponding author: alejandro.lujan@iac.es
1 Instituto de Astrofísica de Canarias (IAC)
2 Dpto. Astrofísica, Universidad de La Laguna (ULL)
3 Oxford University U.K.HARMONI is the first light visible and near-IR integral field spectrograph for the Extremely Large Telescope (ELT). In this poster we will present the prototypes that are being made in the HARMONI Pre-Optics design reviews.
First of all, the prototype of the toroidal mirror mounts will be presented. Their design, testing and toroidal mirror alignment at cryogenic temperature will be discussed.
On the other hand, the prototypes of the mask wheel and shutter mechanism will be presented and how they relate to each other through the optical beam generated by the 30 IPO Opto-mechanical mounts.Atmospheric optics meets integral field spectroscopy to catch the elusive outer
scale of the turbulence
: Begoña García-Lorenzo, Donaji Esparza-Arredondo, Jose A. Acosta-Pulido, and
Julio A. Castro-Almazán
*Corresponding author: begona.garcia@iac.es
The image quality performed by ground-based large telescopes is frequently better than envisioned from the DIMM-measured seeing (S0). This improvement is due to the limited size of the largest eddies of atmospheric turbulence, quantified through the outer scale parameter (L0). The effect of the L0 magnitude is to smooth the low spatial frequency perturbations induced by the turbulence in the wavefront of the light propagating through the atmosphere. This smoothing impacts the performance and operation of adaptive optics (AO) systems for large telescopes, denoting the outer scale as a relevant parameter for AO at a similar level of the seeing. The finite nature of L0 also impacts the wavelength dependence of the image quality, deviating from the natural wavelength (λ) variation of the seeing (i.e., S0(λ) ∝ λ-1/5).
Adopting some simplifications of the turbulence statistics, we obtain an analytical equation to predict the image quality of our system from the actual seeing measured by DIMMs, assuming a typical L0 for our observing site.