Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

Abstract: Photonic circuits are disclosed having an efficient optical power distribution network. Laser chips (InP) having different wavelengths are flip-chip assembled near the center of a silicon photonic chip. Each InP die has multiple optical lanes, but a given die has only one wavelength. Waveguides formed in the photonic chip are optically connected to the lanes, and fan out to form multiple waveguide sets, where each waveguide set has one of the waveguides from each of the different wavelengths, i.e., one waveguide from each InP die. The waveguide network is optimized to minimize the number of crossings that any given waveguide may have, and no waveguide having a particular wavelength crosses another waveguide of the same wavelength. The unique arrangements of light sources and waveguides allows the use of a smaller number of more intense laser sources, particularly in applications such as performance-optimized datacenters where liquid cooling systems may be leveraged.

Abstract: Photonic circuits are disclosed having an efficient optical power distribution network. Laser chips (InP) having different wavelengths are flip-chip assembled near the center of a silicon photonic chip. Each InP die has multiple optical lanes, but a given die has only one wavelength. Waveguides formed in the photonic chip are optically connected to the lanes, and fan out to form multiple waveguide sets, where each waveguide set has one of the waveguides from each of the different wavelengths, i.e., one waveguide from each InP die. The waveguide network is optimized to minimize the number of crossings that any given waveguide may have, and no waveguide having a particular wavelength crosses another waveguide of the same wavelength. The unique arrangements of light sources and waveguides allows the use of a smaller number of more intense laser sources, particularly in applications such as performance-optimized datacenters where liquid cooling systems may be leveraged.

Abstract: A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

Abstract: A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain using bandpass filtering to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra using an inverse Fourier transform. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain using bandpass filtering to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra using an inverse Fourier transform. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain using bandpass filtering to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra using an inverse Fourier transform. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

Abstract: Provided herein are techniques for improved optical absorption measurements in the presence of time-varying etalons. In one aspect, a method for dynamic etalon fitting for adaptive background noise reduction in an optical sensor is provided. The method includes the steps of: obtaining a zero-gas spectrum measured using the optical sensor; obtaining an analyte gas spectrum of a target trace gas measured using the optical sensor; comparing the zero-gas spectrum and the analyte gas spectrum using fit parameters that compensate for drifting etalons in the optical sensor; and dynamically extracting the drifting etalons from the analyte gas spectrum to retrieve concentration of the target trace gas.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: A method of fabricating a gas sensor on a substrate and a gas sensor fabricated on a substrate that includes optical and electronic components are described. The method includes fabricating a laser to output light over a range of wavelengths within a waveguide, fabricating a splitter to split the light output by the laser to a reference waveguide and to a detection waveguide, fabricating a reference cell to house the reference waveguide and a reference gas. An output of the reference waveguide is coupled to a first optical detector and an output of the detection waveguide is coupled to a second optical detector to identify or quantify an ambient gas.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Provided herein are techniques for improved optical absorption measurements in the presence of time-varying etalons. In one aspect, a method for dynamic etalon fitting for adaptive background noise reduction in an optical sensor is provided. The method includes the steps of: obtaining a zero-gas spectrum measured using the optical sensor; obtaining an analyte gas spectrum of a target trace gas measured using the optical sensor; comparing the zero-gas spectrum and the analyte gas spectrum using fit parameters that compensate for drifting etalons in the optical sensor; and dynamically extracting the drifting etalons from the analyte gas spectrum to retrieve concentration of the target trace gas.

Abstract: A method of fabricating a gas sensor on a substrate and a gas sensor fabricated on a substrate that includes optical and electronic components are described. The method includes fabricating a laser to output light over a range of wavelengths within a waveguide, fabricating a splitter to split the light output by the laser to a reference waveguide and to a detection waveguide, fabricating a reference cell to house the reference waveguide and a reference gas. An output of the reference waveguide is coupled to a first optical detector and an output of the detection waveguide is coupled to a second optical detector to identify or quantify an ambient gas.

Abstract: A method of fabricating a gas sensor on a substrate and a gas sensor fabricated on a substrate that includes optical and electronic components are described. The method includes fabricating a laser to output light over a range of wavelengths within a waveguide, fabricating a splitter to split the light output by the laser to a reference waveguide and to a detection waveguide, fabricating a reference cell to house the reference waveguide and a reference gas. An output of the reference waveguide is coupled to a first optical detector and an output of the detection waveguide is coupled to a second optical detector to identify or quantify an ambient gas.

Abstract: A method of fabricating a gas sensor on a substrate and a gas sensor fabricated on a substrate that includes optical and electronic components are described. The method includes fabricating a laser to output light over a range of wavelengths within a waveguide, fabricating a splitter to split the light output by the laser to a reference waveguide and to a detection waveguide, fabricating a reference cell to house the reference waveguide and a reference gas. An output of the reference waveguide is coupled to a first optical detector and an output of the detection waveguide is coupled to a second optical detector to identify or quantify an ambient gas.