A leaky waveguide includes a waveguide configured to propagate light; a defect structure provided on a portion of the waveguide and configured to cause the light propagating in the waveguide to leak outside of the waveguide; and a plurality of detectors provided at predetermined positions adjacent to the defect structure and configured to detect the light leaking from the defect structure. Accordingly, a spectroscope including the leaky waveguide may have a reduced size.

Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

A light splitting device includes an optical waveguide body and a dispersion grating. The optical waveguide body is configured to transmit incident light to the dispersion grating, the dispersion grating is configured to disperse the incident light transmitted by the optical waveguide body into a plurality of spectral lines, and the optical waveguide body is further configured to change propagation directions of the plurality of spectral lines and to emit the plurality of spectral lines.

An optical apparatus includes a waveguide-based frequency-selective structure with one or more input ports and N1 output ports where N1 is 2 or more. If input signals in a pair of input signals are separated in frequency by an integer multiple of the structure's free spectral range, and one of the pair is routed onto one output port, the other in the pair is also routed onto that port. The apparatus also includes: N2 waveguides, where N2<=N1, each having an input port coupled to a corresponding one of the N1 output ports, and a waveguide output port; N3 frequency-selective elements where N3<=N2, each having an input port coupled to a corresponding one of the N2 waveguide output ports and an output surface from which optical emission occurs at an optical frequency-dependent angle; and an element receiving optical emission from the N3 output surfaces, detecting a corresponding intensity pattern.

The present disclosure is directed to a method of forming a polarization grating structure (e.g., polarizer) as part of a grid structure of a back side illuminated image sensor device. For example, the method includes forming a layer stack over a semiconductor layer with radiation-sensing regions. Further, the method includes forming grating elements of one or more polarization grating structures within a grid structure, where forming the grating elements includes (i) etching the layer stack to form the grid structure and (ii) etching the layer stack to form grating elements oriented to a polarization angle.

A measurement system comprises a pulsed laser diode array that includes one or more Bragg reflectors, and wherein the light generated by the array penetrates tissue comprising skin. At least some of the wavelengths of light are in the near infrared. The detection system is synchronized to the laser diode array and comprises an infrared camera and a first receiver comprising a plurality of detectors. The first receiver comprises one or more detector arrays and performs a time-of-flight measurement. The measurement system generates an image, the detection system non-invasively measures blood in blood vessels within or below a dermis layer within the skin based at least in part on near-infrared diffuse reflection from the skin, and the detection system measures absorption of hemoglobin between 700 and 1300 nanometers wavelength range. A processor compares the absorption of hemoglobin between different tissue spatial locations, and the measurement system processes the time-of-flight measurement.

An apparatus includes multiple photonic integrated circuit (PIC) optical spectrometers, and an imaging plane coupled to the PIC optical spectrometers. Each PIC optical spectrometer includes multiple semiconductor chip layers. Each semiconductor chip layer includes multiple arrayed waveguide gratings (AWGs) and a number of on-chip optical detectors.

Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

An optical apparatus includes a waveguide-based frequency-selective structure with one or more input ports and N1 output ports where N1 is 2 or more. If input signals in a pair of input signals are separated in frequency by an integer multiple of the structure's free spectral range, and one of the pair is routed onto one output port, the other in the pair is also routed onto that port. The apparatus also includes: N2 waveguides, where N2<=N1, each having an input port coupled to a corresponding one of the N1 output ports, and a waveguide output port; N3 frequency-selective elements where N3<=N2, each having an input port coupled to a corresponding one of the N2 waveguide output ports and an output surface from which optical emission occurs at an optical frequency-dependent angle; and an element receiving optical emission from the N3 output surfaces, detecting a corresponding intensity pattern.

An optical wavelength dispersion device and manufacturing method therefor are disclosed, wherein the optical wavelength dispersion device includes a waveguide unit and a reflector, wherein the waveguide unit has a first substrate, an input unit, a grating and a second substrate. The input unit is formed on the first substrate and having a slit for receiving an optical signal, a grating is formed on the first substrate for producing an output beam once the optical signal is dispersed, the second substrate is located on the input unit and the grating, and forms a waveguide space with the first substrate, the reflector is located outside of the waveguide unit, and is used for change emitting angle of the output beam.