Abstract: A method of quantifying gas leak rate includes receiving image frames acquired with a camera and including a plume from a gas leak source, determining a real-world size that each pixel represents, identifying pixels corresponding to the plume in a first image frame, calculating gas concentration path lengths of the plume for the pixels in the first image frame, calculating, based on the first image frame and a second image frame, an image velocity field of the plume including displacement vectors for the pixels, identifying, within the first image, a closed boundary enclosing the gas leak source of the plume, and calculating a first gas leak rate in the first image frame by calculating a volume rate of the plume flowing across the closed boundary based on the image velocity field, the gas concentration path lengths, and a time interval between the first and the second image frames.

Abstract: A gas concentration-length quantification method may include acquiring a first image including a gas plume with a camera; identifying and segmenting pixels corresponding to the gas plume in the first image; creating a mask image corresponding to the first image, where only pixels of the mask image corresponding to the gas plume in the first image have non-zero values; generating a background image corresponding to the first image using an image inpainting algorithm with the first image and the mask image as inputs; calculating a gas concentration-length for each pixel corresponding to the gas plume in the first image, based on the first image and the background image data; and triggering an alert when the gas concentration-length for at least one pixel exceeds a threshold level.

Abstract: A terahertz (THz) spectral imaging system includes a THz 2D imaging camera, a tunable THz bandpass filter before the THz camera, and a broadband THz light source. The tunable THz bandpass filter includes a visible or infrared laser source, a spatial light modulator modulating the light to generate a spatially structured light pattern, and a semiconductor plate onto which the light pattern is projected. The light pattern generates carriers in the semiconductor plate to turn it into a metamaterial THz bandpass filter, which is tunable by changing the light patterns. A controller controls the light patterns and the THz camera in a timing sequence to acquire multiple 2D THz images at different THz frequencies. Such THz spectral image data can be further combined with visible images and LiDAR images in a security surveillance system to automatically detect security threats using image fusion and deep learning techniques.

Abstract: A gas concentration-length quantification method may include acquiring a first image including a gas plume with a camera; identifying and segmenting pixels corresponding to the gas plume in the first image; creating a mask image corresponding to the first image, where only pixels of the mask image corresponding to the gas plume in the first image have non-zero values; generating a background image corresponding to the first image using an image inpainting algorithm with the first image and the mask image as inputs; calculating a gas concentration-length for each pixel corresponding to the gas plume in the first image, based on the first image and the background image data; and triggering an alert when the gas concentration-length for at least one pixel exceeds a threshold level.

Abstract: A terahertz (THz) spectral imaging system includes a THz 2D imaging camera, a tunable THz bandpass filter before the THz camera, and a broadband THz light source. The tunable THz bandpass filter includes a visible or infrared laser source, a spatial light modulator modulating the light to generate a spatially structured light pattern, and a semiconductor plate onto which the light pattern is projected. The light pattern generates carriers in the semiconductor plate to turn it into a metamaterial THz bandpass filter, which is tunable by changing the light patterns. A controller controls the light patterns and the THz camera in a timing sequence to acquire multiple 2D THz images at different THz frequencies. Such THz spectral image data can be further combined with visible images and LiDAR images in a security surveillance system to automatically detect security threats using image fusion and deep learning techniques.

Abstract: A light emitting device includes a substrate layer, a first electrode layer, a light emitting layer, and a patterned second electrode layer. The patterned second electrode layer includes a periodic grating structure having a grating period ?g less than or equal to 200 nm and the patterned second electrode layer and the light emitting layer are separated by at most 100 nm.

Abstract: A light emitting device includes a substrate, a first electrode disposed on the substrate, a light emission layer (EML) disposed on the first electrode, a second electrode disposed on the EML, and a capping layer disposed on the second electrode. A thickness of the second electrode is not more than 50 nm, a refractive index of the capping layer is less than a refractive index of the EML, and the EML and the second electrode are separated by a distance not more than 100 nm.

Abstract: A system and method for multi-spectral gas concentration analysis that includes using a library of multiple sets of optimized spectral sensitivities prepared in advance, and a multi-spectral IR gas analyzer tuned to a set of optimized spectral sensitivity. The multi-spectral IR gas analyzer measures spectral absorption of gas using one or more different sets of optimized spectral sensitivities.

Abstract: A light emitting device includes a substrate layer, a first electrode layer, a light emitting layer, and a patterned second electrode layer. The patterned second electrode layer includes a periodic grating structure having a grating period ?g less than or equal to 200 nm and the patterned second electrode layer and the light emitting layer are separated by at most 100 nm.

Abstract: A light emitting device includes a substrate, a first electrode disposed on the substrate, a light emission layer (EML) disposed on the first electrode, a second electrode disposed on the EML, and a capping layer disposed on the second electrode. A thickness of the second electrode is not more than 50 nm, a refractive index of the capping layer is less than a refractive index of the EML, and the EML and the second electrode are separated by a distance not more than 100 nm.