Abstract: An optical signal to be detected enters single photon avalanche diode cells (SPAD) in a SPAD array and triggers photo event currents. Optical waveguides in the sensor carry an internal optical signal and a 1xN splitter divides the optical power into waveguide branches 206, 206?, . . . 206N-1. At the coupling structure, comprising 207, 207?, . . . 207N-1 positive-intrinsic-negative diode photodetector/waveguide structures, photo event currents from SPAD cells are converted to a change in the internal optical signal, by modifying internal optical signals 208, 208?, . . . 208N-1. A waveguide combiner further integrates the modified internal optical signals resulting from the photo event currents from all the cells in the sub-array. After all waveguide branches' signals are combined, a photodetector detects the internal optical signal and outputs an electrical signal.

Abstract: A two-beam steering device comprising two single-beam steering devices and a motorized, rotating base stage, wherein each single-beam steering device is able to steer an electromagnetic wave beam in a full field of regard, wherein the two single-beam steering devices are fixed on top of the rotating base stage. The two-beam steering device can point the two individual beams into any direction pair in the entire field of regard with full flexibility.

Abstract: An optical routing system for free space optical communication is disclosed. The system has a transmitter and a receiver that use free space optical communication, and includes an optical path based on waveguide where an optical signal is routed from the proximity of the transmitter to the proximity of the destination. This system has advantages in terms of mitigating line-of-sight issues, as well as potentially reducing the overall coupling loss that would be otherwise incurred due to beam divergence of free space propagation for long distance.

Abstract: A system and method wherein electromagnetic radiation is used for free-space communication and wireless power transfer. The electromagnetic radiation used is preferably optical radiation. The optical free-space communication and wireless power transfer system includes an optical receiver device comprising an optical filter, a photodetector, and a photovoltaic cell, wherein a band of the incoming optical radiation is extracted by the optical filter and directed to the photodetector for communication data signal detection. The remaining optical radiation is converted by the photovoltaic cell into electrical power so that the harvested energy can be stored, used as the power source of the photodetector, or used as the power source of external devices.

Abstract: A photonic integrated circuit (PIC) spectrometer for sensing the spectroscopic signature of airborne molecules, comprising a dispersive element to separate the spectral information spatially, and a tuning mechanism for said dispersive element to convert the spectral information to time-dependent information. The approach allows the PIC spectrometer to have a single (or a few) output pin(s), enabling sensing of the environment with a simple packaged chip that is compact, lightweight, energy efficient and low cost, making it suitable for platforms that have a small form factor, a small power budget, and are cost sensitive, such as mobile devices.

Abstract: Small form-factor, sensitive and efficient waveguide devices capable of nondispersive infrared gas or liquid sensing and photocatalysis are designed based on photonic integrated circuits. The devices comprise three-dimensional optical waveguiding structures and preferably integrated light sources and photodetectors. Since the length of the waveguide scales with the number of waveguiding layers, a plurality of layers is used to design high-sensitivity sensors and high-efficiency photocatalysis devices. In one embodiment, titanium dioxide absorbs ultraviolet light to generate an electron-hole pair which, in the presence of water and oxygen, generates radicals that react with and mineralize undesirable organic compounds, such as the lipid membranes that envelope and protect viruses such as Coronavirus Disease 2019 (COVID-19), allowing to pry apart the membranes and destroy the cells.