NIRPS (Near Infra Red Planet Searcher) is a near-infrared, fiber-fed, high-resolution, high precision radial velocity (pRV) spectrograph to be installed at ESO 3.6m telescope in La Silla Observatory in Chile. High precision radial velocity measurements require to have a very stable optical assembly. The gluing of optical elements in their mounts with A12 epoxy was selected as bonding process to minimize kinematic motion and optimize stability. However, coefficient of thermal expansion (CTE) mismatch between optical elements, their mountings and the glue may produce large local mechanical stress. Finite element analysis (FEA) was performed to estimate the thermal stress at room temperature and cryogenic temperature (80K). The selection of suitable bonding parameters (gluing setup, glue thickness, etc.) was a challenge given the CTE difference of optical elements (ZnSe and ZerodurTM) and holding flexures (SS304 and InvarTM). Extensive tests were performed to find a suitable bonding strategy. Gluing samples were tested under cryogenic temperature during several weeks. Mechanical shear stress tests were also performed to show that glued assembly could survive a 12g vertical load.
Proc. SPIE. 11447, Ground-based and Airborne Instrumentation for Astronomy VIII
KEYWORDS: Telescopes, Spectrographs, Aerospace engineering, Exoplanets, Planets, Lanthanum, Space operations, Spectroscopes, James Webb Space Telescope
NIRPS is a near-infrared (YJH bands), fiber-fed, high-resolution precision radial velocity (pRV) spectrograph currently under construction for deployment at the ESO 3.6-m telescope in La Silla, Chile. Through the use of a dichroic, NIRPS will be operated simultaneously with the optical HARPS pRV spectrograph and will be used to conduct ambitious planet-search and characterization surveys through a 720-night of guaranteed time allocation. NIRPS aims at detecting and characterizing Earth-like planets in the habitable zone of low-mass dwarfs and obtain high-accuracy transit spectroscopy of exoplanets. Here we present a summary of the full performances obtained in laboratory tests conducted at Université Laval (Canada), and the first results of the on-going on-sky commissioning of the front-end. Science operations of NIRPS is expected to start in late-2020, enabling significant synergies with major space and ground instruments such as the JWST, TESS, ALMA, PLATO and the ELT.
Initiatives in education and training tailored to industry needs have been a core part of the bi-annual SPIE Optics Education and Outreach conference, accounting for over 50% of papers since its inception in 2010. In this paper, the authors explore whether this conference has been useful to the readership by reviewing the contributions to this meeting for industry-oriented activities. Accounting for this scope, a bibliographic review of the literature of all five proceedings of OP301 is presented to describe the participants in terms of their affiliations and background, the proceedings’ taxonomy, and the metrics for downloads and citations. An integrative review will support this report to present lessons learned in six key areas of (1) technician training, (2) continuous education and training in industry, (3) in-company training and internships, (4) local and regional economic development through optics and photonics education and research, (5) progress on accreditation and certification, and (6) programs in innovation and entrepreneurship. The findings will be used to evaluate trends in formal and informal methods for industry-related programs and make recommendations for areas of potential focus for future meetings to continue serving wider segments of the community.
Funding opportunities in science are essential to the research and development ecosystem. Numerous and competitive, the vast majority focus on scientific accomplishment. While the advancement of science remains a top priority, some funding agencies started to reshape their programs to include strict training requirements, from training plans included in proposals to regular evaluations of training progress. At the centre of this change is the recognition of the universities and colleges educational mission through research, and the need for a highly qualified workforce serving industry, science, and research. It is this need for applied research training, expressed by the Canadian aerospace community, that led to the creation of the Canadian Space Agency’s FAST (Flights and Fieldwork for the Advancement of Science and Technology) funding activity in 2011. Among the three main objectives of the 2017 opportunity, two target training the next and current generations of scientists and engineers for space-related areas in Canada by (1) developing and maintaining a critical mass of researchers, and (2) increasing the level of student employability by exposing them to practical experiences. In this paper, we report about the context behind CSA FAST’s creation, the funding opportunity model, and the impact of the funding activity. Concrete results are also shown for the HiCIBaS project, funded by CSA FAST 2015, an ambitious balloon-borne mission with an optical payload for wavefront sensing and exoplanet imaging that was led by 5 graduate students as part of their master’s program, and that culminated with a stratospheric balloon flight in August 2018.
Proc. SPIE. 10745, Current Developments in Lens Design and Optical Engineering XIX
KEYWORDS: Infrared cameras, Infrared sensors, Infrared imaging, Imaging systems, Cameras, Sensors, 3D modeling, Time of flight cameras, Modulation transfer functions, Time of flight imaging
Active imaging techniques have been, and will remain relevant as an integral part of the sensor network needed in mobile robotics navigation, most commonly with the use of LiDARs. For close range applications, time-of-flight (TOF) cameras are an alternative to more expensive LiDARs. The Kinect v2 (Kinect for XboxOne) has been used frequently as a range imaging camera in machine vision research because of its low cost and good performance. For mobile robotics applications moving at low speed, a larger field of view than the original (70° X 60°) would be desirable to increase awareness of the surroundings, and also detect other moving objects in the trajectory.
Our main goal is therefore to increase the Kinect v2 field of view while keeping its main feature of depth measurements. A simple but effective solution consists in using a conversion lens to increase the ray collection angle before the rays enter the IR camera. Depth measurements remain possible from each pixel using TOF with the Kinect v2 modulated signal, provided the field of illumination matches the field of view. A trade-off has to be made between accuracy of depth measurement, optical performance and field of view/illumination enhancement. Therefore, we modified a Kinect v2 to characterize its optical performances and evaluate its relevancy for applications requiring accurate knowledge of the 3D surroundings.
A field of view improvement of the Kinect v2 and other similar TOF cameras could offer an alternative at minimal cost for depth measurements in machine vision, specifically in mobile robotics research where object detection and mapping tasks are frequently carried out.
The Photonic Games are a yearly outreach event created in 2008 to spark teenagers’ interest in light. In teams, high school students face several optics challenges designed to appeal to various abilities and interests. In the past 10 years, more than 1531 participants, 425 volunteers and 100 organizers have taken part in this unique student-organized activity. Following the 10th edition, past presidents took the time to reflect together on what they learnt from their experience and identified key elements explaining the long-lasting success of this initiative. Metrics have been defined to track the evolution of the activity’s efficiency and are presented herein.
We have developed a prototype of a low-cost and versatile 3D-printed perfusion chamber for digital holographic microscopy (DHM) of primary neurons in culture. The imaging chamber is 3D-printed in biocompatible plastic. It is easily convertible between a closed configuration, for refractive index - cellular thickness decoupling, and an open configuration, for electrophysiology. In the closed arrangement, the imaging volume is small, allowing a rapid laminar flow with a fast turnover for an optimal implementation of the decoupling procedure. This paper highlights especially the challenges faced while designing and prototyping the 3D-printed closed perfusion chamber with a small imaging volume for DHM. As all 3D-printed mechanical parts were initially leaking because of internal porosities, we developed a simple sealing protocol using acetone vapors to smooth surfaces. Using this protocol, almost all mechanical parts were successfully sealed. Therefore, the production process of the actual prototype, i.e. the 3D printing and the sealing method, is satisfactory for our target application in the field of microfluidics.
With their large field of view, anamorphosis, and areas of enhanced magnification, panomorph lenses are an interesting choice for navigation systems for mobile robotics in which knowledge of the surroundings is mandatory. However, panomorph lenses special characteristics can be challenging during the calibration process. This study focuses on the calibration of two panomorph stereoscopic systems with a model and technique developed for narrow-angle lenses, the “Camera Calibration Toolbox for MATLAB.” In order to assess the performance of the systems, the mean reprojection error (MRE) related to the calibration and the reconstruction error of control points of an object of interest at various locations in the field of view are used. The calibrations were successful and exhibit MREs of less than one pixel in all cases. However, some poorly reconstructed control points illustrate that an acceptable MRE guarantees neither the quality of 3-D reconstruction nor its uniformity in the field of view. In addition, the nonuniformity in the 3-D reconstruction quality indicates that panomorph lenses require a more accurate estimation of the principal point (center of distortion) coordinates to improve the calibration and therefore the 3-D reconstruction.
Proc. SPIE. 9192, Current Developments in Lens Design and Optical Engineering XV
KEYWORDS: Visual process modeling, Cameras, Calibration, Image processing, Lens design, 3D modeling, Ray tracing, 3D metrology, Optical design software, Tolerancing
Camera calibration is essential for any optical system used to obtain 3D measurements from images. The precision of the 3D depth estimation relies on an appropriate camera model and the accurate estimation of model parameters. These parameters are sensitive to environmental conditions and it is well established that a vision system should be calibrated in operating conditions. This is not always possible since the calibration process is often tedious and time-consuming. Unfortunately, the use of poorly estimated calibration parameters for 3D reconstruction and measurements may lead to suboptimal performance of the system and inaccurate depth estimation. This paper presents a technique using an existing camera model and optical design software to perform calibration simulations. This virtual calibration technique allows for a study of the impact of environmental conditions on the calibration parameters. Using this procedure, it is also possible to predict the statistical behavior of the calibration parameters considering the chosen fabrication processes and tolerances. It can assist vision scientists in the choice of the optical system that best meets the requested precision of the 3D reconstruction. This technique could eventually be integrated in the lens design process to create more reliable optical systems that could be calibrated and used in a range of environmental conditions with a very small variation of their calibration parameters.
Young people often have biased and pre-conceived ideas about scientists and engineers that can dissuade them from considering a career in optics. This situation is compounded by the fact that existing resources on careers in optics are not suitable since they mostly focus on more general occupations such as a physicist and an electrical engineer. In addition, the linguistic register is not adapted for students, and many of these resources are only available to guidance counselors. To create appropriate resources that will inform high school students on different career opportunities in optics and photonics, we sought the collaboration of our local optics community. We selected seven specific occupations: entrepreneur in optics, university professor, teacher, technician, research and development engineer, sales representative and graduate student in optics. For each career, a list of daily tasks was created from the existing documentation by a guidance counselor and was validated by an expert working in the field of optics. Following a process of validation, we built surveys in which professionals were asked to select the tasks that best represented their occupation. The surveys were also used to gather other information such as level of education and advice for young people wishing to pursue careers in optics. Over 175 professionals answered the surveys. With these results, we created a leaflet and career cards that are available online and depict the activities of people working in optics and photonics. We hope that these resources will help counter the negative bias against scientific careers and inform teenagers and young adults on making career choices that are better suited to their preferences and aspirations.
In the last decade, wide-angle stereoscopic systems using fisheye lenses have been proposed but the compromise made to obtain a large field of view is low resolution and high distortion resulting in imprecise depth estimation of objects in a 3D scene. High and non-uniform distortion, especially in the azimuthal direction, is often considered as a weakness of panoramic lenses because it is sometimes difficult to compensate for by image processing. The aim of this paper is to present an alternative to existing stereoscopic panoramic systems by taking advantage of nonuniform distortion and anamorphosis in Panomorph lenses. There are many challenges related to this project such as the
calibration of the system and the creation of a 3D depth estimation algorithm that suits the resolution of the different
areas in the images. This paper presents different configurations of two Panomorph lenses within a stereoscopic device and a study of specific parameters to highlight their impact on the quality of 3D reconstruction of an object in a scene. Finally, an overview of future work is presented.
Many resources are available for groups that are interested in doing outreach activities with high school students. Most
of these resources are dedicated to the experimentation of optical phenomena but do not include information about
careers in optics and photonics. Created in 2010 for the Canadian Institute for Photonic Innovations (CIPI), the
Canadian Photonic Kit was distributed throughout Canada. Using this kit as a starting point, Université Laval’s OSA
and SPIE student chapters, helped by the CIPI-Student network, will create a multi-platform resource addressing three
subjects: (1) optical phenomena, (2) research in optics and photonics, and (3) related careers. This paper presents a
timeline of the project and its main parts: the Canadian Photonic Kit and an expansion pack related to careers, a
demonstration laboratory located within a research center and its virtual tour, and printable material for teachers and
guidance counselors.
Worldwide, volunteers from student associations and non-profit organizations carry out outreach activities with high
school students in their classrooms. Most of the time, these activities highlight optical phenomena but do not provide
information about the reality of researchers in companies and universities. To address this issue, Université Laval’s OSA
and SPIE student chapters set up a demonstration laboratory dedicated to outreach, located in a research center. In this
paper, we list the advantages of this type of facility as well as the steps leading to the creation of the laboratory, and we
give an overview of the demonstration laboratory.
Here, we report for the first time the optical testing of modern 1.3, 5, and 8 megapixel panoramic lenses available on the market for security and surveillance applications. Our first test focused on the measurement of the image mapping and more particularly on the inverse of the instantaneous field of view expressed in pixels/degree (IFOV−1). This kind of measurement provides a valuable comparison parameter for the user community. The second test was a measurement of a modulation transfer function (MTF) system. All tested lenses were coupled with the same camera in order to measure the MTF system using the edge response. While this measurement is not a measurement of the MTF of the lens, it provides a basis for comparison between the different lenses. Our measurement shows that the IFOV is more robust than the MTF to manufacturing and assembly errors. This provides robustness to the unwrapping image post-processing. The MTF measurements show that all the tested lenses have an on-axis MTF of 35% at Nyquist frequency over 2 (Ny/2) for a 2.2 μm pixel pitch.
Almost every aspect concerning the design of modern panoramic lenses brings new challenges to optical designers.
Examples of these include ray tracing programs having problems finding the entrance pupil which is moving through the
field of view, production particularities due to the shape of the front lenses, ways of tolerancing these systems having
strong distortion, particular setups required for their characterization and calibration, and algorithms to properly analyze
and make use of the obtained images. To better understand these modern panoramic lenses, the Optical Engineering
Research Laboratory at Laval University has been doing research on them during the past few years. The most
significant results are being presented in this paper.
Controlled distortion, as in commercial panomorph lenses (Immervision), is used to image a specific part of the object
with more pixels than in a normal fisheye lens. This idea is even more useful when a zone of interest vary in time with
dynamically adjustable distortion as in a panoramic locally magnifying imager. Another axis of research is the use of
modern computational techniques such as wavefront coding in wide-angle imaging systems. The particularities of such
techniques when the field of view is large or with anamorphic imagers are considered. Presentation of a novel circular
test bench in our laboratories, required to calibrate and check the image quality of wide-angle imaging system, follows.
Another presented setup uses a laser and diffractive optical elements to compactly calibrate wide-angle lenses. Then, a
discussion of the uniqueness in tolerancing these lenses, especially the front elements due to the large ratio between lens
diameter and entrance pupil diameter, is included. Lastly, particularities with polarization imaging and experiments of
triangle orientation detection tests before and after unwrapping the distorted images are briefly discussed.
It often takes one single event to interest teenagers in a topic that will become a passion or a career. It is in this spirit that
the SPIE and OSA Student Chapters at Université Laval created the Photonic Games three years ago, to kindle an
interest in teenagers towards studies and careers in optics. The activity, offered each year to more than a hundred grade
11 students, is divided in two parts. First, we offer a hands-on workshop in their classrooms about reflection, refraction,
dispersion, birefringence and polarization. A few days later, all the students come to the Centre d'optique, photonique et
laser (COPL) at Université Laval for a day of competition where a volunteer physics student accompanies each team of
four students. Challenges are various to promote the qualities that make great scientists: creativity, teamwork,
knowledge, inquisitiveness, self-confidence and perseverance. The first two editions of the Photonic Games have proven
to be beneficial for the students, teachers and volunteers, and we endeavor to improve it as we construct on our
experience with the past editions to fine-tune and improve the Photonic Games concept.
Panoramic imaging is of growing importance in many applications around the world spurred by the development of
digital imaging. Panoramic lens characteristics are unique and their careful characterization can be a challenge. For
example, the price to pay for a large field of view in this type of lens is high distortion in the image. For vision
applications like security or inspection, a precise knowledge of the distortion introduced by panoramic lenses is essential
to produce natural unwrapped views to the operator. Of special concern is the image quality which must be uniformed
over the entire field of view because all directions are equally important. In addition, two hemispheric images can also
be stitched together to create a complete spherical image. For these reasons, we have developed a dedicated setup to
study the distortion and the image quality produced by panoramic lenses. The test setup is made of a 75-cm radius
cylindrical structure with targets placed on it. Using referenced equally-spaced targets, we obtained the radial image
mapping curves for various azymuthal angles, allowing us to calculate the full-field resolution map. Also, transition
targets were used to find field-dependent spatial frequency where the MTF is 50%. We tested four different panoramic
lenses, two panomorph lenses and two fisheyes. For each lens, we discussed the experimental resolution and MTF
curves and compared some of those results to theoretical design data.
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