An optical interferometry measurement system has lots of advantages, and it is widely used in various applications. For a longer range and higher speed of optical interferometry measurement, it is required a higher burden of data amount during the data acquisition (DAQ) process. A novel light source called comb-swept laser was proposed to solve the heavy load in DAQ, but comb-swept laser needs a solution for the distance aliasing problem. Recently, optical Vernier sampling was suggested to solve the distance aliasing problem with two different free spectral range (FSR) combs. This research introduces a new type of FSR-tunable comb-swept laser for optical Vernier sampling to measure long-range with high speed without high-speed DAQ.

This work is based on the concept of integrating metasurfaces as passive elements to enhance LiDAR capabilities. We demonstrated a proof-of-concept of a LiDAR imaging system capable of acquire images at 1 million of frames per second using a faster scanner active device with a field of view up to 150°X150°. The active element redirects the light into a metasurface deflector which enhances the field of view. MHz imaging rate and 3D imaging is demonstrated. Finally, we discuss applications and limitations of using such approach, which is a strong candidate to pave the way into full autonomous vehicles.

A novel scheme of white light interferometer (WLI) surface imaging system is demonstrated using a tunable-path-difference source (TPDS). TPDS is applied by adopting Mach–Zehnder interferometry to resolve the vibration noise, which the mechanical scanning has caused in the reference path of conventional WLI. Compared with WLI using comb-spacing-swept source (CSWS), WLI with TPDS is superior in terms of signal-to-noise ratio and total exposure of optical intensity into the camera. Through the improved performance, WLI with TPDS can successfully acquire 3D images at the micron scale and multi-layered tomographic information with fine detail.

Optical metrology provides direct feedback for AR/VR/MR design verification and manufacturability evaluation by imitating the human eye’s optical properties of resolution, color sensitivity and uniformity over large FOVs, self-adaption to focus location, brightness and contrast. This paper defines a generic, standardized optical metrology platform to efficiently integrate various optical metrology instruments into the platform’s global coordinate system by utilizing a specially designed active-optical calibration target to precisely map the optical entrance pupil of any optical metrology instrument and device under test (DUT) to a common reference point, providing effective data correlation. The platform can easily accommodate common AR/VR/MR optical metrology equipment for measurements of: MTF/contrast, color and brightness, virtual distance, angular FOV, and binocular alignment error; to provide a unified metrology platform for optical measurements.

Speckle patterns have proven to be a versatile tool in various areas of metrology. Different levels of resolution have been achieved depending on how the speckles are produced and the analysis method that is employed. We show three particular applications of speckle metrology: measurement of refractive index variation (10^-10 uncertainty), wavelength variations (10^-18 m uncertainty), and displacement (10^-11 m uncertainty), where the uncertainties are made very low by an appropriate choice of scattering geometry and analysis method. We explore this both analytically and experimentally. We also discuss the multiplexing capability of speckle patterns, and demonstrate this capability for the simultaneous measurement of polarisation and wavelength variation of multiple light sources.

Laser-based soldering, also known as Solderjet-bumping, is an established process for the bonding of optical and mechanical components under laboratory conditions at normal atmosphere. The present study shows the implementation and adaption of the bonding technology to a vacuum environment with pressure below 10-4 mbar, in which x-ray optics are assembled and aligned. To demonstrate the performance, assembly campaigns for x-ray optics demonstrators in air and under vacuum conditions were performed. Environmental and mechanical tests on sample-level-studies were carried out. The results of the study show that the solderjet-bumping technique is capable for the bonding of x-ray optics and other components under vacuum conditions. The strength of the bond is not affected by the vacuum environment.

We propose to record "en face" Full Field OCT interferometric images of paintings on canvas using a cooled MCT camera working in the range 3-5.5 micrometers coupled to a glowbar broadband source that allows to reach shot noise limited detection. Penetration in various paints is spectacular at these large wavelengths: we measure a mean free path 5 to 10 times larger than at visible/near IR wavelengths. We find that the canvas is easily observed under the paint. This result, obtained without averaging, paves the way to a non-contact, non-destructive, more detailed analysis of paintings than existing IR techniques.

Determining the radial velocity and atmospheric composition of exoplanets is typically performed using dispersive spectroscopy. However, while this approach is versatile, spectrometers for such applications are complex, expensive and are bulky instruments. In contrast, tunable fiber-based filters are commercially available and can be used for low cost, passive remote gas sensing. In this work, we experimentally demonstrate Fabry-Pérot based correlation spectroscopy in a simple, low-cost, compact, and stable instrument package for astrophotonic gas sensing. We also show via simulation that exoplanet radial velocities can be determined simultaneously.

We will present a new approach of linearized focal plane technique (LIFT), formerly developed by ONERA, which results in an improvement of a factor of 16 (4x4) of the spatial resolution. This technology is based on the combination of standard SH technology with phase retrieval algorithms applied on all spots of the microlens array that provides information on high spatial frequencies. We will show some measurements performed on extremely complex wavefronts. This technology presents very promising perspectives for optical and freeform metrology and can advantageously replace, at lower cost and better usability, Fizeau interferometry.

Geiger-mode Avalanche Photodiode (GmAPD) sensors operating in the short-wave infrared wavelength range provide single-photon sensitivity along with precise time-of-flight measurement capability. Cameras built from such sensors are uniquely suited for use in LIDAR systems. We present the development of a computational model of a GmAPD device. We apply this model to identify and optimize key parameters in the epitaxial growth structure, with the goal of producing maximum photon detection efficiency while maintaining a low dark count rate. These simulations suggest a modest design adjustment will result in a relative increase in detection efficiency of more than 15% at typical operating bias voltage, when compared to a legacy control design. A new epitaxial growth and device fabrication campaign has been executed to test the results of the simulation. We will present test results from sensor devices fabricated from both the optimized and control designs.

The extreme dynamic range (XDR) program performs a pre-exposure and uses a classification structure for the determination of the signal’s patterns and intensities in a star-field. Using this and the unique architecture of Thermo Fisher Scientific CID821 image sensor the signals were targeted and properly monitored throughout the main exposure. This allowed for a single exposure with high DR and a collection of signals that are typically ignored and saturated. This approach takes full advantage of the CID821 image sensor’s abilities.