Hyperspectral imaging (HSI) captures spatial and spectral information from a scene. Conventional scanning HSI systems often yield low optical throughput, slow frame rates, large datasets and/or resolution trade-offs. One can exploit spectral compression in applications where spectral information is sparse in some representation and illumination is controllable, like optical endoscopy. This work experimentally demonstrates fast HSI using a compressed sensing architecture involving a programmable illuminator and a fast monochrome camera. We reconstruct the scene’s hypercube, showing high PSNR (up to 39 for 10 measurements). Our versatile implementation offers higher optical throughput, smaller acquisition times and data volumes compared to conventional HSI approaches.

Nanoscale 3D printing enables a wide variety of applications from photonics to biology. Specifically, using a DMD to project light into a triplet fusion upconversion 3D printing resin can allow rapid printing. This requires selecting a single plane at a time. However, as an image is projected into the resin, the z-resolution of the printing system can be limited by substantial light intensity around the focal plane. Using a home-built setup, we study how we can manipulate the images uploaded to the DMD to optimize the resolution of our prints. We present our findings towards high-resolution nanoscale volumetric 3D printing.

Volumetric additive manufacturing (VAM) via tomographic projection is an emerging platform for ultra-rapid 3D printing. By projecting all layers in parallel, print times orders of magnitude faster than standard polymer 3D printing can be easily achieved, without the need for support scaffolds. Despite these advantages, print results are in certain cases inferior to commercial vat polymerization due to the infancy of the technique. In this talk, we will outline recent progress made at the National Research Council of Canada to extend the capabilities of VAM and address inherent challenges in VAM. Topics covered will include the role of depletion and polymerization kinetics on print quality and novel resins for larger, faster, and functional prints.

We conducted a comprehensive characterization of key phenomena in digital micromirror devices (DMD) using an ultrashort pulse beam of 98.8 fs @800nm. Firstly, we determined the fluence threshold, which was found to be 0.19 J/cm^2. Secondly, we quantified the nonlinear dispersion introduced by the DMD in the pulse beam using the SPIDER method. Our measurements revealed a second order GDD value of 473 fs^2, a third-order dispersion (TOD) of 3700 fs^3, and a fourth-order dispersion (FOD) of -2027000 fs^4. Our research significantly advances our understanding of DMD behavior and its interaction with ultrashort pulses, thereby optimizing their use in optical applications.

We leverage the classic compressed sensing concept of the Single Pixel Camera to build an imaging system for objects in scattering media, such as fog. With the DMD and ultra-fast FPGA-based signal sampling as the enabling technologies, we can combine compressed sensing, advanced image reconstruction algorithms and Time-of-Flight detection to achieve video-level frame rates. We discuss the benefits of our approach compared to established techniques in the context of autonomous vehicles in particular, and imaging in harsh conditions in general.

Microsphere photolithography (MPL) uses self-assembled hexagonal close-packed microspheres as optical elements to produce photonic nanojets (PNJ) in a layer of photoresist. The information required for hierarchical patterning is embedded in the illumination light field. In this work, dual spatial light modulator (SLM) system is employed to attain precise control over the light field in MPL, which can significantly enhance the flexibility and efficiency of the fabrication process. A digital micro device (DMD) located at the front Fourier plane is used to control the AOI at the back focal plane. A liquid crystal (LC) device is placed in the intermediate image plane to regulate the local illumination intensity, which is subsequently projected onto the image stage. Both the DMD and SLM encode the illumination AOI and intensity received by each microsphere. The resolution and control processes of the system are investigated. The capability is demonstrated by creating functional hierarchical metasurfaces.

Polarization modulation plays a crucial role in various optical applications, e.g., microscopic imaging, optical communication, quantum optics, and remote sensing etc. In this work, we present a digital micromirror device (DMD)-based approach to modulate the polarization of a femtosecond laser at the DMD’s pattern rate, i.e., 4.2 kHz. Femtosecond laser pulses have been widely known for their ultrafast temporal characteristics and unique ability to induce complex nonlinear optical effects. Our work employs a DMD to realize efficient and versatile polarization modulation, surpassing conventional methods, e.g., liquid crystal-based spatial light modulator, in terms of both speed and cost.