UK OPTICAL DESIGN MEETING
Wednesday 16 March 2022
University of Glasgow
Glasgow, Scotland
UK OPTICAL DESIGN MEETING
Wednesday 16 March 2022
University of Glasgow
Glasgow, Scotland
Poster Abstracts
Computational 3D localisation microscopy at the nanoscale
Conall Thompson, Jonathan Taylor and Andrew R Harvey
School of Physics and Astronomy
University of Glasgow
Glasgow, ScotlandAlthough the resolution of a microscope is limited by diffraction to about half a wavelength, point-like single molecules or beads can be localised with nanometre precision, but only over a depth of field of about a micron. Engineering of the microscope pupil function can yield exotic point-spread functions, which enable localisation of point sources throughout extended 3D volumes, but their spatial extent limits the maximum density of emitters that can be imaged. We describe how computational imaging using a twin-Airy PSF enables nanometre-scale localisation of far larger numbers and densities of point sources than previously reported. Our new technique shows promise for enhanced 3D single-molecule imaging and nano-scale chemical sensing in biology.
Lenslet Arrays for Medical Spectacles
Maik Locher, Johannes Courtial
University of Glasgow
Glasgow, ScotlandA properly constructed telescope window array may aid with several visual impairments, such as central vision loss, field of view constrictions and more. While in theory using idealised lenses such applications have already been proven computationally, steps converting it into a reality have been met with a number of issues. Here we will attempt to overcome current limitations ranging from cross talk between telescopes to image pixilation. Some steps to solve these may include turning pixels into channels and field of view steering. If this is successful, it will be possible to build and test such novel medical spectacles.
PSF Engineering for Snapshot Volumetric Imaging
Daniel Olesker, Andrew R. Harvey and Jonathan M. Taylor
University of Glasgow
Glasgow, ScotlandThe time needed to acquire 3D microscopy images via conventional serial-scanning methods is limited by their dependence on translating the illumination or sample. For highly dynamic scenes, faster imaging methods are required that don’t rely on scanning to image in 3D. We report a hybrid method that combines pupil-plane-engineering with computational reconstruction to achieve snapshot 3D imaging. By choosing appropriate microscope point-spread functions, we extend the depth-of-field while simultaneously encoding depth information into 2D images, enabling full volumetric reconstruction to be performed post-acquisition with a novel deconvolution scheme. We demonstrate our method experimentally across a range of scales and samples.
Multi-Scale imaging of the retina
Joel Terry, Guillem Carles, A. R. Harvey
School of Physics and Astronomy
University of Glasgow
Glasgow, ScotlandImaging the retina is fundamentally limited by the optical quality of the eye optics, but this varies enormously across the field of view; from near diffraction-limited on axis to strongly aberrated for imaging of the periphery. It is almost impossible to design a single optical system to correct for these field-varying aberrations. We describe how multi-scale imaging, involving multiple cameras and local aberration correction enables near-diffraction-limited imaging across an extended field of view.
Portable microscopy using smartphones for use in low-resource settings
Oliver Higgins
University of Glasgow
Glasgow, Scotland
Despite there being around 1400 recognised human pathogens and parasites, two-thirds of deaths are caused by just a few species; around 20 varieties of bacteria, parasites and viruses. Identifying the presence of these pathogens is a key step in diagnosis, but more than 50% of African populations do not have access to adequate public health services, leaving many communities to suffer high mortality rates from otherwise treatable conditions. We present a low-cost 3D-printed smartphone microscope which uses deep learning to automate the diagnosis of parasitic infections to reduce the equipment requirements for disease diagnosis in underserved settings.
The Importance of Optical Performance Stability of the European Solar Telescope.
Marta Belío-Asin
Canary Islands Institute of Astrophysics
Tenerife, Spain
The European Solar Telescope (EST) will be a 4-metre class solar telescope, which will require overcoming major challenges at the limits of technology. To reach its objectives, an important aspect is to ensure that the performance of the system will not be affected during operation. In this sense, sensitivity analysis is an essential design concern to be addressed. Several sources of degradation will compromise the reliability of the system; these include environmental conditions such as gravity, temperature or wind, which will displace the optical elements of the telescope from its nominal position. By developing an image motion sensitivity analysis it is possible to relate the motion of the optical components with the image motion at any of the focus of the system, F1, F2 and F3 (Coudé Focus) with the aim of adjusting the telescope while operating. This process is also meant to be a baseline for the active optics subsystem, a crucial part of the telescope with a strategy that is being defined to prevent any misalignment due to these environmental constraints and to ensure compliance with image quality requirements.
Modelling and fabrication of low cost miniature visible and near-infrared spectrometers using linear variable filters
Lewis Fleming
University of the West of Scotland
Paisley, Scotland, UK
To meet the ever-increasing demand for low-cost, lightweight and portable miniature spectrometer systems for industrial and aerospace applications, linear variable filters (LVFs) have a number of advantages over traditional optical dispersion devices utilising prisms and gratings. Here, we describe the optical system design of an LVF s pectrometer for visible and near-infrared (NIR) wavelengths. A spectrometer optical system is modelled (Zemax OpticStudio) using a combination of reflector mirrors, parabolic concentrator and light pipe; wavelength selection is modelled by importing an LVF design (Essential Macleod) as a tapered coating into the spectrometer model. The LVFs were fabricated using microwave plasma assisted DC magnetron sputtering. Spectrometer chassis was realised using 3D printing. A 3D printed LVF based spectrometer system was fabricated and operation over visible (450 nm – 900 nm) and near infrared (1500 nm – 2500 nm) wavebands demonstrated.
Automatic tube lens design from stock optics for
microscope remote-refocusing systems
Wenzhi Hong and Chris Dunsby
Photonics Group, Department of Physics
Imperial College London, London, UK
In order to operate remote-refocussing microscope systems correctly, it requires that the overall magnification of the first two microscope systems matches the ratio of the refractive indices in sample and intermedia image spaces. However, commercially available tube lenses are not always suitable to produce the desired overall magnification, which leads to a need to rapidly produce tube lenses with low expense and diffraction-limited performance – particularly when prototyping different configurations. Tube lenses can be formed using a pair of stock achromatic doublets, which provides the benefits of a simple design that can be purchased rapidly. However, selecting appropriate pairs of achromatic doublets from stock optics is a time-consuming process, as many combinations can be considered. Here, we present two software packages (Catalogue Generator and Doublet Selector) developed in MATLAB that uses the application programming interface (ZOS-API) to the Zemax OpticStudio optical design software to realise an automatic search of stock achromatic doublets to produce microscope tube lenses with a specified focal length, entrance pupil diameter and maximum design field angle. An algorithm to optimise principal plane positions in versions of OpticStudio before 20.2 was also introduced to enable the use of older software versions.