This technology revolves around Optical Coherence Tomography (OCT), a noninvasive imaging method that provides detailed cross-sectional images of tissue microstructure and blood flow. OCT utilizes either time domain (TDOCT) or Fourier domain (FDOCT) approaches, with FDOCT offering superior sensitivity and speed. Doppler OCT combines Doppler principles with OCT to visualize tissue structure and blood flow concurrently. Additionally, polarization-sensitive OCT detects tissue birefringence. Advanced methods aim to enhance the speed and sensitivity of Doppler OCT, crucial for various clinical applications such as ocular diseases and cancer diagnosis. Swept source FDOCT systems further improve imaging capabilities by increasing range and sensitivity. Overall, this technology represents significant advancements in biomedical imaging, offering insights into both structural and functional aspects of tissue physiology.

Researchers at the University of California, Davis have developed an invention that utilizes an integrated Raman scanning head and machine vision for high throughput chemical analysis of liquid biopsy samples.

Researchers at UC Irvine have developed a new method to 3D-print free-form silica glass materials which produces products with unparalleled purity, optical clarity, and mechanical strength under far milder conditions than currently available techniques. The novel processing method has potential to radically transform microsystem technology by enabling development of silica-based microsystems.

This patent application describes methods for non-invasive, label-free imaging of the cellular immune response in human skin using a nonlinear optical imaging system.

The disclosed methods offer a robust approach to accurately quantify skin optical properties across different skin tones, facilitating improved diagnosis, monitoring, and treatment in dermatology.

Diagnosing retinal disease, which affects over 200 million people worldwide, requires expensive and complicated analysis of the structure and function of retinal tissue. Recently, UCI developed a training algorithm which, for the first time, is able to assess tissue health from images collected using more common and less expensive optics.

Researchers at the University of California, Davis have developed layered 2D MoS2 nanostructures that have their light-interactive properties improved by intercalation with transition and post-transition metal atoms, specifically Copper and Tin.

Hyperspectral imaging (HSI) is an emerging imaging modality for medical applications, especially in disease diagnosis and image-guided surgery. HSI acquires a three-dimensional dataset called hypercube, with two spatial dimensions and one spectral dimension. Spatially resolved spectral imaging obtained by HSI provides diagnostic information about the tissue physiology, morphology, and composition. Researchers from UC San Diego developed a new method using a pair of femtosecond mid-infrared and visible excitation pulses to distinguish chromophores, including molecules and quantum dots, that possess nearly identical emission spectra using multiplexed conditions in a three-dimensional space. 

Volumetric additive manufacturing and vat-polymerization 3D printing methods rapidly solidify freeform objects via photopolymerization, but problematically raises the local temperature in addition to degree-of-conversion (DOC). The generated heat can critically affect the printing process as it can auto-accelerate the polymerization reaction, trigger convection flows, and cause optical aberrations. Therefore, temperature measurement alongside conversion state monitoring is crucial for devising mitigation strategies and implementing process control. Traditional infrared imaging suffers from multiple drawbacks such as limited transmission of measurement signal, material-dependent absorptions, and high background signals emitted by other objects. Consequently, a viable temperature and DOC monitoring method for volumetric 3D printing doesn’t exist.To address this opportunity, UC Berkeley researchers have developed a tomographic imaging technique that detects the spatiotemporal evolution of temperature and DOC during volumetric printing. The invention lays foundations for the development of volumetric measurement systems that uniquely resolve both temperature and DOC in volumetric printing.This novel Berkeley measurement system is envisaged as an integral tool for existing manufacturing technologies, such as computed axial lithography (CAL, Tech ID #28754), and as a new research tool for commercial biomanufacturing, general fluid dynamics, and more.

Brief description not available

Photonic integrated circuits (PICs) have emerged as an encouraging platform for many fields due to their compact size, phase stability, and can be mass produced in semiconductor foundries at low cost. As such, PIC enabled waveguide-to-free-space beam delivery has been demonstrated towards ion trap quantum computing, atomic clocks, optical tweezers, and more. Grating couplers are commonly used, as through careful design, they can generate diffraction-limited focused spots into free space from a waveguide input. However, they suffer from many drawbacks – they have a narrow optical bandwidth, limited efficiency, are sensitive to light polarization and the emission angle is sensitive to fabrication variation.Quantum systems require stable delivery of multiple wavelengths, often spanning the near ultraviolet (NUV), visible, and near infrared (NIR) spectrum, to multiple locations tens to hundreds of micrometers above the PIC. This requirement exacerbates the pitfalls of grating couplers; their single-wavelength operation necessitates multiple gratings per unit cell. With more gratings to fabricate, fabrication variance takes a greater toll on device performance. UC Berkeley researchers have devised a new approach and device to deliver light from in-plane waveguides to out-of-plane free space beams in a low-loss, broadband manner. In particular, this device is used for controlling qubits in a trapped ion quantum computer, but in general the system is suitable for other integrated beam delivery applications.

Brief description not available

 The dynamic patterning of 3D optical point clouds has emerged as a key enabling technology in volumetric processing across a number of applications. In the context of biological microscopy, 3D point cloud patterning is employed for non-invasive all-optical interfacing with cell ensembles. In augmented and virtual reality (AR/VR), near-eye display systems can incorporate virtual 3D point cloud-based objects into real-world scenes, and in the realm of material processing, point cloud patterning can be mobilized for 3D nanofabrication via multiphoton or ultraviolet lithography. Volumetric point cloud patterning with spatial light modulators (SLMs) is therefore widely employed across these and other fields. However, existing hologram computation methods, such as iterative, look-up table-based and deep learning approaches, remain exceedingly slow and/or burdensome. Many require hardware-intensive resources and sacrifices to volume quality.To address this problem, UC Berkeley researchers have developed a new, non-iterative point cloud holography algorithm that employs fast deterministic calculations. Compared against existing iterative approaches, the algorithm’s relative speed advantage increases with SLM format, reaching >100,000´ for formats as low as 512x512, and optimally mobilizes time multiplexing to increase targeting throughput. 

High-frequency photoacoustic tomography (> 20 MHz) is becoming increasingly important in biomedical applications. However, it requires data acquisition (DAQ) to have commensurately high sampling rate, which imposes challenges to hardwires and increases the cost of building a PA imaging system. For example, the sampling rate should be higher than 80 MHz to cover 100% bandwidth of a 26-MHz transducer (Nuquist limit). A commercial PA imaging system such as Vevo LAZR X (Fujifilm VISUALSONICS Inc. ON, Canada) with 80-MHz sampling rate can cost more than 990,000$ in the United States.Many PA groups use clinical ultrasound DAQs, which are low cost but also have a low sampling rate, e.g., the iu22 system’s sampling rate is 32 MHz.

The California Lighting Technology Center at UC Davis in collaboration with the Center for Mind and Brain have developed a novel lighting technology approach for stress recovery and stress mitigation.

Dynamic patterning of light is used in a variety of applications in imaging and projection. This is often done by spatial light modulation, in which a coherent beam of input light is modified at the pixel level to create arbitrary output patterns via later interference. Traditional approaches to spatial light modulation suffer from a high operating burden, especially as the number of pixels increases, and incomplete coverage of the optical surface. This results in high device complexity, and cost, as well as enormous real-time computation requirements, reduced optical performance, and optical artifacts.To address these problems, researchers at UC Berkeley have developed a method for wiring groups of pixels, such as annular rings, parallel strips, or radial strips. This takes advantage of the fact that most spatial light modulation tasks can be accomplished by combining a number of simple “primitive phase profiles”, in which not all pixels need be independent of each other. In this co-wiring method, individual optical elements remain at the pixel level, but are wired together in a way that they move in precisely the coordinated manner to produce one of these primitive phase profiles. This allows for high frame rates, high coverage of the optical plane, and a degree of sensitivity impossible to produce with large, geometric optical elements that exist in prior art.

Dynamic patterning of light is used in a variety of applications in imaging and projection. This is often done by spatial light modulation, in which a coherent beam of input light is modified at the pixel level to create arbitrary output patterns via later interference. Traditional approaches to spatial light modulation suffer from a fundamental restriction on frame rate which has led manufacturers to seek the diminishing returns of continually increasing pixel number, resulting in impractical device sizes, complexity, and cost, as well as enormous real-time computation requirements. Additionally, these devices inherently produce monochromatic and speckled frames due to the requirement that the input beam be coherent.To address these problems, researchers at UC Berkeley have developed a device which can perform spatial light modulation with a frame rate ~20 times higher than existing technologies. This allows for a smaller number of pixels to produce high resolution, full color images by interleaving images of different colors and scanning rapidly across a screen in a similar way to the operation of CRT televisions Researchers have also developed an efficient and robust fabrication method, which combined with the smaller pixel number of these devices could cause them to be much more cost effective than existing technologies.

Silicon photonics is increasingly used in an array of communications and computing applications. In many applications, photonic chips must be coupled to optical fibers, which remains challenging due to the size mismatch between the on-chip photonics and the fiber itself. Existing approaches suffer from low alignment tolerance, sensitivity to fabrication variations, and complex processing, all of which hinder mass manufacture.To address these problems, researchers at UC Berkeley have developed a coupling mechanism between a silicon integrated photonic circuit and an optical fiber which uses a microlens to direct and collimate light into the fiber. Researchers have demonstrated that this device can achieve low coupling loss at large alignment tolerances, with an efficient and scalable manufacturing process analogous to existing manufacture of electronic integrated circuits. In particular, because the beam is directed above the silicon chip, this method obviates dry etching or polishing of the edge of the IC and allows the silicon photonics to be produced by dicing in much the same way as present electronic integrated circuits.

Large format active or deformable mirrors can enable optical applications that are difficult to achieve with more conventional-sized deformable mirrors. In particular, adaptive secondary mirrors (ASMs) can be integrated into telescopes and provide adaptive optics corrections. However, making facesheets for ASMs is challenging. Current facesheet fabrication processes are costly and risky. Hot forming approaches for forming curved facesheets have been developed, but these methods typically require a mold for the facesheet to slump into.

For decades, researchers have been developing “cool roof” materials to cool buildings and save on energy usage from air conditioning. Cool roof materials are engineered to maximize infrared thermal emission, allowing heat to be effectively radiated into outer space and the building to cool down. Conventional cool roof materials emit heat even when it is cold outside, which exacerbates space heating costs and can outweigh energy-saving benefits. A temperature adaptive radiative coating (TARC) material was developed in 2021 that adapts its thermal emittance to ambient temperatures using metal-insulator transitions in vanadium oxide. TARC is projected to outperform existing roof materials in most climate areas, but the complicated structure required high-cost fabrication techniques such as photolithography, pulsed laser deposition, and XeF2 etching, which are not scalable.To address this problem, UC Berkeley researchers have developed a new scalable temperature-adaptive radiative coating (STARC). STARC has the same thermal emittance switching capability as TARC, allowing the thermal emittance to be switched between high- and low- emittance states at a preset temperature. However, STARC can be produced using high-throughput, roll-to-roll methods and low-cost materials. The STARC material also has an improved lifetime. As an added benefit, while cool roof materials are often engineered with uniformly low solar-absorption, the color and solar absorption of STARC can be tuned for aesthetic purposes or to meet local climate-specific needs.

Brief description not available

Researchers at UC Irvine have developed a novel optical fiber technology that uses newly developed “zero-refractive index” material as a guiding medium, overcoming the significant limitations of conventional optical fiber where light properties are limited by glass core material. This novel technology will dramatically improve optical communication transmission speed and power by orders of magnitude.

The development of Low-Gain Avalanche Detectors (LGADs) that make controlled use of impact ionization has led to an advancement in the use of silicon diode detectors in particle detection, particularly in the arena of ultrafast (~10 ps) timing. For what are today considered to be “conventional” LGADs, the high fields needed to induce the impact ionization process lead to breakdown between the separated n-p junctions that are used to simultaneously deplete the sensors and establish the readout segmentation. As a result, working devices have included a Junction Termination Extension (JTE) that provide electrostatic isolation between neighboring implants, but at a cost of introducing a dead region between the sensor segments that is insensitive to the deposited charge from an incident particle. The width of this dead region is 50 µm or more, making conventional LGAD sensors inefficient for granularity scales much below 1mm. On the other hand, demands from the particle physics (4D tracking) and photon science (high frame-rate X-Ray imaging) communities call for granularity at the 50 µm scale. Thus, there is great interest in overcoming the current granularity limits of LGAD sensors. There are several ideas, under various levels of development, that have been proposed to circumvent the JTE limitAC-coupled (“AC-LGAD”) LGADs eliminate the need for the JTE by making use of a completely planar (non-segmented) junction structure, and then establish the granularity entirely through the electrode structure, which is AC-coupled to the planar device through a thin layer of insulator. Since charge is not collected directly by the electrodes, there is a point-spread function that relates the signal location to the pad (electrode) response that is a property of the effective AC network formed by the highly doped gain layer just below the insulating layer and the electrode structure. Prototype devices exhibit good response and timing characteristics.Inverse (“ILGAD”) LGADs also eliminate the need for the JTE by making use of a planar junction structure. In this case, the electrode structure is placed on the side of the device opposite the junction. Prototypes with appealing signal characteristics have yet to be produced. In addition, the manufacture of these devices requires processing on both sides of the sensor, which is significantly more difficult than the single-sided processes used for conventional and AC LGADs.Trench-isolated (“TI-LGAD”) LGADs attempt to replace the JTE with a physical trench etched around the edge of the detector segment, which is then filled with insulator. This approach is very new, and its proponents hope to be able to use it to reduce the dead area between segments to as little as 5 µm. First prototypes are just recently available and are under study. Much work remains to be done to show that this approach will produce a stable sensor, and to see how small the dead region can be made.

Methods for monitoring device operating conditions and current are shifting towards the use of optical measurements, which are are less susceptible to electromagnetic noise. Existing light emission techniques utilize complex components, like laser diodes and photodiodes, to measure device current, rendering such techniques expensive to implement.

Brief description not available