Abstract: Waveguide Bragg gratings, optical reflectors and lasers including optical reflectors are disclosed. The optical reflectors include a waveguide, perturbations proximate to the waveguide to create a Bragg grating in the waveguide, and a DC index control structure positioned to vary the DC index along at least a portion of the Bragg grating. In laser embodiments, the waveguide may be coupled to the second end of a semiconductor gain element to form an external cavity having an optical length and a cavity phase. The gain element and optical reflector may be monolithically integrated on a substrate or separate structures.

Abstract: There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

Abstract: High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Abstract: High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Abstract: Waveguide Bragg gratings, optical reflectors and lasers including optical reflectors are disclosed. The optical reflectors include a waveguide, perturbations proximate to the waveguide to create a Bragg grating in the waveguide, and a DC index control structure positioned to vary the DC index along at least a portion of the Bragg grating. In laser embodiments, the waveguide may be coupled to the second end of a semiconductor gain element to form an external cavity having an optical length and a cavity phase. The gain element and optical reflector may be monolithically integrated on a substrate or separate structures.

Abstract: A novel transmitter is proposed that provides broadband all-optical linearization of a Mach-Zehnder interferometer (MZI) modulator for use in high linearity RF photonic links and optical up-converter and down-converter schemes. It is based on an amplitude modulated (AM) MZI modulator where part of the laser Carrier is passed around the MZI modulator and added back to the AM signal, creating a Controlled Carrier-AM (CC-AM) signal. In this new scheme, a dual output MZI modulator is utilized, and the alternative output (Carrier*) is used together with the Carrier from the laser to create a new signal, LO*, which when coherently combined with the AM signal can reduce or completely cancel its 3rd order intermodulation distortion.

Abstract: High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Abstract: A low noise, single mode laser includes a semiconductor gain element generating light and having a highly reflective first end forming a first end of a laser cavity. The gain element may be monolithically or discretely integrated with, or distinct from, and coupled to a waveguide comprised of a low loss material with a refractive index ‘n’ greater than 3. The waveguide includes a Bragg grating forming the second end of the laser cavity. A cavity phase control section may be provided between the gain element and the Bragg grating. Two photodetector monitors provide a feedback signal for locking the light from the gain element to a specific wavelength on the Bragg grating reflection spectrum by varying at least one of the cavity phase control section and the gain element bias current. The Bragg grating may have a physical length larger than 10 mm and that occupies at least 50% of the optical length of the external cavity.

Abstract: There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

Abstract: High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Abstract: A novel transmitter is proposed that provides broadband all-optical linearization of a Mach-Zehnder interferometer (MZI) modulator for use in high linearity RF photonic links and optical up-converter and down-converter schemes. It is based on an amplitude modulated (AM) MZI modulator where part of the laser Carrier is passed around the MZI modulator and added back to the AM signal, creating a Controlled Carrier-AM (CC-AM) signal. In this new scheme, a dual output MZI modulator is utilized, and the alternative output (Carrier*) is used together with the Carrier from the laser to create a new signal, LO*, which when coherently combined with the AM signal can reduce or completely cancel its 3rd order intermodulation distortion.

Abstract: There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

Abstract: The present invention reduces the level of optical reflections created in a photonic integrated circuit (PIC) going back into an integrated laser through Reflection Engineering; optimizing the phase/timing and position of optical reflections inherent to a PIC design while adding engineered reflections to the PIC to allow inherent reflections to be reduced or eliminated. The Wavelength Division Multiplexed (WDM) geometric optical isolator of the present invention combines an array of closely spaced WDM lasers with an array of modulators in a novel geometry in order to provide effective optical isolation of the lasers.

Abstract: The present invention reduces the level of optical reflections created in a photonic integrated circuit (PIC) going back into an integrated laser through Reflection Engineering; optimizing the phase/timing and position of optical reflections inherent to a PIC design while adding engineered reflections to the PIC to allow inherent reflections to be reduced or eliminated. The Wavelength Division Multiplexed (WDM) geometric optical isolator of the present invention combines an array of closely spaced WDM lasers with an array of modulators in a novel geometry in order to provide effective optical isolation of the lasers.

Abstract: High-performance ultra-wideband Phased Array Sensors (PAS) are disclosed, which have unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for a Receive PAS are provided by wafer scale photonic integration including heterogeneous integration of III-V materials and ultra-low-loss silicon nitride waveguides, combining key component technologies into complex PIC devices. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors providing the capability to combine many RF photonic signals with very low loss. The architecture also includes optical down-conversion, as well as digital signal processing to improve the linearity of the system. Simultaneous multi-channel beamforming is achieved through optical power splitting of optical signals to create multiple exact replicas of the signals that are then processed independently.

Abstract: A low noise, single mode laser includes a semiconductor gain element generating light and having a highly reflective first end forming a first end of a laser cavity. The gain element may be monolithically or discretely integrated with, or distinct from, and coupled to a waveguide comprised of a low loss material with a refractive index ‘n’ greater than 3. The waveguide includes a Bragg grating forming the second end of the laser cavity. A cavity phase control section may be provided between the gain element and the Bragg grating. Two photodetector monitors provide a feedback signal for locking the light from the gain element to a specific wavelength on the Bragg grating reflection spectrum by varying at least one of the cavity phase control section and the gain element bias current. The Bragg grating may have a physical length larger than 10 mm and that occupies at least 50% of the optical length of the external cavity.

Abstract: There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

Abstract: A laser including: a gain chip; an external cavity incorporating a Bragg grating; and a baseplate; wherein a first end of the gain chip has a high reflectivity facet forming a first end of the laser cavity; a second end of the gain chip has a low reflectivity facet; and a second part of the external cavity comprises a Bragg grating, supported by the baseplate, the temperature of the baseplate being maintained through a feedback loop; wherein the optical length of the external cavity is at least an order of magnitude greater than the optical length of the gain chip; wherein the Bragg grating is physically long and occupies a majority of the length of the external cavity and is apodized to control the sidemodes of the grating reflection.

Abstract: The present invention reduces the level of optical reflections created in a photonic integrated circuit (PIC) going back into an integrated laser through Reflection Engineering; optimizing the phase/timing and position of optical reflections inherent to a PIC design while adding engineered reflections to the PIC to allow inherent reflections to be reduced or eliminated. The Wavelength Division Multiplexed (WDM) geometric optical isolator of the present invention combines an array of closely spaced WDM lasers with an array of modulators in a novel geometry in order to provide effective optical isolation of the lasers.

Abstract: High-performance ultra-wideband Phased Array Sensors (PAS) are disclosed, which have unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for a Receive PAS are provided by wafer scale photonic integration including heterogeneous integration of III-V materials and ultra-low-loss silicon nitride waveguides, combining key component technologies into complex PIC devices. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors providing the capability to combine many RF photonic signals with very low loss. The architecture also includes optical down-conversion, as well as digital signal processing to improve the linearity of the system. Simultaneous multi-channel beamforming is achieved through optical power splitting of optical signals to create multiple exact replicas of the signals that are then processed independently.