UK OPTICAL DESIGNERS’ MEETING
Thursday 19th September 2013
Rutherford Appleton Laboratory
Harwell, Oxfordshire
Abstracts
Lighter, smaller, cheaper, better: the promise of computational imaging
Andy Harvey1, Guillem Carles1, James Downing1,2, Gonzalo Muyo3, Tom Vettenburg4, Nick Bustin5 and Andy Wood5
1School of Physics and Astronomy, University of Glasgow
2ST Microelectronics, Edinburgh
3School of Engineering and Physical Sciences, Heriot-Watt University
4School of Physics and Astronomy, University of St Andrews
5Qioptiq, St Asaph, Wales
The design of modern imaging systems is intricately concerned with the control of optical aberrations in systems that can be manufactured at acceptable cost and with acceptable manufacturing tolerances. Traditionally this involves a multi-parameter optimisation of the lens optics to achieve acceptable image quality at the detector. There is increasing interest in a more generalised approach whereby digital image recovery is incorporated into the design process and the performance metric to be optimised is quality of the image at the output of the image processor. The requirement of the optics is then to capture the necessary and sufficient information at the detector that enables computational recovery of a high quality image. Relaxation on the requirements of the optics offers scope for significant reductions in volume and weight of the overall system, whilst transference of the burden of complexity from high-cost optics to low-cost digital computation offers overall reduction in cost.
We will discuss here the most promising methods in computational imaging, including: wavefront coding for increased aberration tolerance, super-resolution sub-pixel imaging using time-sequential and multi-aperture imaging and multiscale imaging for increased field of view. We will discuss the trade-offs involved in the application of these techniques in thermal infrared and visible imaging systems, showing how very useful performance enhancements can be achieved in practical systems.
Following a brief review of a range of computational imaging technologies, we shall illustrate the potential benefits and weaknesses of three distinct techniques; wavefront coding, multi-aperture systems and multi-scale optics. We shall discuss the need for new developments in design software to allow the full potential of the technology to be realised, show a number of novel design solutions and, for wavefront coding, results from technology demonstrator hardware.
Optical design of a hyper-spectral imager using image slicer mirrors
David Lee
UK Astronomy Technology Centre
Royal Observatory, EdinburghFor many scientific imaging applications, such as remote sensing and medical imaging, it is important to capture both imaging and spectral information about the target scene under observation. A popularly used technique for achieving this is hyper-spectral imaging where a spectrometer slit is incrementally scanned across a target scene to gradually gather spatial and spectral information. A typical hyper-spectral imager consists of an imaging system which illuminates a single slit spectrometer. If it is necessary to observe more than one wavelength channel then additional spectrometers can be added, fed by dichroic filters and an optical relay system. However observing multiple wavelength channels with multiple spectrometers can be inefficient in terms of the number of optical components, number of detectors, and volume of the instrument.
Double Vision: Cine Lens Quality
Ian Marshall
BAE Systems Electronics and integrated Solutions
Cine lenses form moving images on sensors that compress highlights and accentuate lower intensity information. Therefore the properties of lenses that affect image quality tend to differ from those normally associated with camera lens image quality. There is a difference in the way that optical engineers and cinematographers approach image quality. This paper uses a test video containing lens comparisons to describe three of the lens design issues that are important in cine images, and relates them to properties of lens design.
Updated Optical Design of WEAVE Spectrograph for Ground-Based Astronomy
Kevin Rogers †, Kevin Middleton, Ian Tosh, Remko Stuik
Optical Systems Group, RAL Space, STFC
Rutherford Appleton Laboratory
Remko Stuik, Nova-Astron, Netherlands† Presenting author
WEAVE is the next generation wide field spectroscopy facility to be added to the William Herschel Telescope in La Palma. RAL Space is responsible for the design of the spectrograph optics. The progression of the design from a first-order approximation toward a manufacture ready model will be explained. The final layout of the optical system along with performance shall be described and illustrated in detail.
Design of LED-Lit, Light-Guiding Daytime Running Lamps for Automobiles
Thomas L.R. Davenport
Optical Solutions Group, Synopsys, Inc
In recent years, novel, high-luminance LEDs have emerged in the automotive market which are enabling revolutionary exterior automotive lighting designs. In this presentation, we demonstrate an approach for designing daytime running lamps (DRLs) that meet European (ECE) intensity specifications for stand-alone DRLs and are optimized for uniformity of spatial appearance. The depths of extraction elements along the length of the light guide are adjusted in order to extract uniform flux. Circular DRLs, as well as generalized curve, ‘eyebrow’ designs, are considered.
Plastic Optics: possibilities and limitations in high tech applications
Stefan Bäumer
TNO, the Netherlands
During the last years 'plastic optics' has gone through a large growth in both, acceptance and applications. While for a long time viewed as low(er) quality optics, improvements in manufacturing and processing have made it possible to move plastic optics in to larger high tech markets as well. However in order to create working applications using plastic optics, certain rules and tolerances have to be maintained during the design process.
In the presentation an overview on recent application of plastic optics will be given. Design rules and possible tolerances will be explained and plastic optics materials with their properties will be discussed.
SMETHODS: Training and Hands-on Practice in Optical Design and Simulation for SMEs
Paul Urbach and Florian Bociort
Delft University of Technology, the Netherlands
SMETHODS is an FP7 funded support action which organizes training in optical design in four different domains of optics, targeted at small and medium sized European enterprises to gain and keep a leading position in optics and photonics. Participation in training sessions is free – although priority is given to employees of small and medium sized European enterprises (SMEs). The European consortium offering SMETHODS consists of 7 partners that are the most prominent academic institutions in optical design in their countries. Through full integrated collaborative training sessions, the consortium provides professional assistance as well as hands-on training in a variety of design tasks in imaging optics, non-imaging optics, wave optics and diffraction optics.
ITER Challenges for Optical Design
Roger B. Huxford
RBH Optics
West Sussex
ITER is an experimental Fusion Reactor. It is one of the world’s largest scientific projects and is currently under construction in the South of France. At full power it will generate 500MW by fusing Deuterium and Tritium at temperatures up to 150 million °C in the core of the Plasma. To control and monitor the processes going on in the Plasma many optical diagnostic systems are required which are challenging for the optical designer because of the harsh operating environment. This presentation will look at the issues and show some optical diagnostic systems to overcome these challenges.
Update on Optical Materials
Ralf Jedamzik
Schott AG, Global Applications
Included in the realm of optical materials are not only optical glasses and filter glasses, but also IR materials, active and passive laserglass and thin and ultra-thin glasses with specific properties.
Reproducible production processes provide optical glasses with tightest refractive index and Abbe number tolerances and highest homogeneity available in today’s market. The characterization of the bulk laser induced damage threshold of optical glasses enables a more flexible optical design in industrial applications.
Infrared chalcogenide glasses have an excellent transmittance in the short-, medium- and far IR range. Due to a low dn/dT and dispersion, these glasses unfold their strength in color corrected optical systems or athermal imaging environments.
With increasing requirements of the applications, the requirements on the optical materials and their properties are also increasing. In this presentation a cross section of current optical material topics will be presented.
Poster Abstracts
Design of a 3D coaxial multi-pass recirculator for laser beam - electron beam interactions
Kevin Dupraz LAL/CNRS, Kevin Cassou LAL/Université Paris-sud, Nicolas Delerue LAL/CNRS, Philippe Fichot LAL/CNRS and Fabian Zomer LAL/Université Paris-sud
The Compton scattering process between a relativistic electron bunch and a high power laser pulse is still today the most efficient technique to generate high brilliance gamma ray beams. However, the main drawback of this physical process is its small cross-section which has to be compensated the use of a laser power at the limit of the existing technology to provide a high flux of gamma rays. In this presentation, we describe the optical design of the interaction point of a Compton gamma ray machine which has been proposed for the ELI-NP project. We have developed an optical system capable of recirculating 32 times a high energy pulsed laser beam. We fully modeled this apparatus using the Code V simulation software in order to perform tolerance studies. We obtain a low loss and aberration free system which provides a constant laser – electron beams crossing angle.
Improving Opto-electronic Neural Stimulation with Micro-LED arrays and micro-optics
Lionel Chaudet1, Prof. Mark Neil1, Dr Patrick Degenaar2, Dr Kamyar Mehran2, Dr Rolando Berlinguer-Palmini2, Pleun Maaskant3, Dr Peter Lanigan4
1Imperial College London, Dept. of Physics, Photonics Group, Blackett Lab, UK
2Newcastle University, School of Electrical, Electronic and
Computer Engineering, Newcastle upon Tyne, UK
3National Tyndall Institute, Cork, Ireland
4Scientifica, East Sussex, UK
Seventh Framework Programme (FP7)
We present the design and implementation of a projection and micro-optics system for use with a micro-LED array to improve the fill-factor by collecting a larger proportion of the LED emission and directing it correctly and efficiently to the sample plane and its testing on biological samples.
The breakthrough discovery of a nanoscale optically gated ion channel protein, Channelrhodopsin 2 (ChR2), and its combination with a genetically expressed ion pump, Halorhodopsin, allowed the direct stimulation and inhibition of individual action potentials in neurons with light alone. This work reports developments of ultra-bright electronically controlled optical array sources with enhanced light gated ion channels and pumps for use in systems to further our understanding of both brain and visual function.
This work is undertaken as part of the European project, OptoNeuro.
The Technique of Photonics Design
Laurel Hopkins, The Photonics Academy of Wales at Bangor, PAWB
The Photonics Academy of Wales at Bangor, PAWB, wants to reach a wide range of industries to offer a route to Photonics through a unique learning style that challenges the methods of traditional teaching. PAWB aims to teach its students techniques and not simply facts. Through learning about observation, investigation and design we aim to give students the freedom to design their own unique photonics prototypes. Emphasis is placed on practical skill and hands on learning with theory being delivered through instant tutorials, i.e. lectures of only a few minutes, to cover any issues arising during the design and building process. PAWB is offering 6 modules accredited by Bangor University at Grade 4, equivalent to a first year HE course, entitled the 'Principles of Photonics'. This Work Based Learning opportunity is available for companies within the Wales convergence zone.