Abstract: Systems and methods for precision control of microresonator (MR) based frequency combs can implement optimized MR actuators or MR modulators to control long-term locking of carrier envelope offset frequency, repetition rate, or resonance offset frequency of the MR. MR modulators can also be used for amplitude noise control. MR parameters can be locked to external reference frequencies such as a continuous wave laser or a microwave reference. MR parameters can be selected to reduce cross talk between the MR parameters, facilitating long-term locking. The MR can be locked to an external two wavelength delayed self-heterodyne interferometer for low noise microwave generation. An MR-based frequency comb can be tuned by a substantial fraction or more of the free spectral range (FSR) via a feedback control system. Scanning MR frequency combs can be applied to dead-zone free spectroscopy, multi-wavelength LIDAR, high precision optical clocks, or low phase noise microwave sources.

Abstract: Systems and methods for precision control of microresonator (MR) based frequency combs can implement optimized MR actuators or MR modulators to control long-term locking of carrier envelope offset frequency, repetition rate, or resonance offset frequency of the MR. MR modulators can also be used for amplitude noise control. MR parameters can be locked to external reference frequencies such as a continuous wave laser or a microwave reference. MR parameters can be selected to reduce cross talk between the MR parameters, facilitating long-term locking. The MR can be locked to an external two wavelength delayed self-heterodyne interferometer for low noise microwave generation. An MR-based frequency comb can be tuned by a substantial fraction or more of the free spectral range (FSR) via a feedback control system. Scanning MR frequency combs can be applied to dead-zone free spectroscopy, multi-wavelength LIDAR, high precision optical clocks, or low phase noise microwave sources.

Abstract: Examples of systems and methods for integrated photonic broadband microwave transceivers are disclosed based on integrated coherent dual optical frequency combs. In some cases, when the system is configured as a transmitter, multiple radio frequency (RF) carriers can be generated, which can either be encoded independently, or used for broadcasting the same information into different bands. In some cases, when the system is configured as a receiver, the spectrum of the input signal can be sliced into several spectral segments for low-bandwidth detection and analysis. In some systems, the optics-related functionalities can be achieved via integrated optic technology, for example based on silicon photonics, providing tremendous possibilities for mass-production with significantly reduced system footprint.

Abstract: Low phase noise radio frequency (RF) sources generated by voltage controlled oscillators (VCOs) are described. Optical modulators driven by a VCO may be used to generate optical side-bands to cw lasers. The spectral extent of said side-bands can be increased via frequency broadening in highly nonlinear waveguides. Free running mode locked low phase noise comb oscillators can be used as reference oscillators to generate beat signals between those side-bands and individual comb modes at distal spectral regions, thereby creating an error signal used to reduce the phase noise of VCOs and the generation of low phase noise RF signals. VCO phase noise may be reduced by using free-running modelocked comb lasers phase locked to external frequency references, by omitting a reference comb and using a nonlinear interferometer for generating an error signal, or by locking a slave comb to the modulation frequency of an intra-cavity modulator driven by the VCO.

Abstract: Examples of systems and methods for integrated photonic broadband microwave transceivers are disclosed based on integrated coherent dual optical frequency combs. In some cases, when the system is configured as a transmitter, multiple radio frequency (RF) carriers can be generated, which can either be encoded independently, or used for broadcasting the same information into different bands. In some cases, when the system is configured as a receiver, the spectrum of the input signal can be sliced into several spectral segments for low-bandwidth detection and analysis. In some systems, the optics-related functionalities can be achieved via integrated optic technology, for example based on silicon photonics, providing tremendous possibilities for mass-production with significantly reduced system footprint.

Abstract: Systems and methods for precision phase noise measurements of radio frequency (RF) oscillators are provided. An RF signal under test can be modulated on a continuous wave (cw) laser carrier frequency via generation of modulation sidebands using an appropriate modulator. A photonic delay line can be implemented as a self-heterodyne detection system for the phase noise, allowing for photonic down-conversion of the phase noise measurement to direct current (DC). The self-heterodyne detection system allows detection outside of any 1/f noise issues. Ultra-low phase noise detection for RF frequencies in a range from below 1 GHz to beyond 100 GHz is enabled with a low noise floor in the whole frequency range. Higher-order modulation sidebands can further reduce the noise floor of the system. Ultra-low noise RF (microwave) output can be generated. The RF signal under test can be generated by a dielectric resonance oscillator or opto-electronic oscillator.

Abstract: Low phase noise radio frequency (RF) sources generated by voltage controlled oscillators (VCOs) are described. Optical modulators driven by a VCO may be used to generate optical side-bands to cw lasers. The spectral extent of said side-bands can be increased via frequency broadening in highly nonlinear waveguides. Free running mode locked low phase noise comb oscillators can be used as reference oscillators to generate beat signals between those side-bands and individual comb modes at distal spectral regions, thereby creating an error signal used to reduce the phase noise of VCOs and the generation of low phase noise RF signals. VCO phase noise may be reduced by using free-running modelocked comb lasers phase locked to external frequency references, by omitting a reference comb and using a nonlinear interferometer for generating an error signal, or by locking a slave comb to the modulation frequency of an intra-cavity modulator driven by the VCO.

Abstract: To provide a high-density optical interconnect device, information processing device and data transmission method which are able to suppress limitations caused by the widening of light beams and the size of lenses. An optical interconnect unit includes a plurality of first lenses and a plurality of second lenses corresponding to a plurality of light-emitting element groups, and a plurality of light beams emitted from the plurality of light-emitting element groups pass through plurality of first lenses and the plurality of second lenses. The optical interconnect unit also includes a plurality of third lenses and a plurality of fourth lenses, and light beam groups pass through any one of the plurality of third lenses and the plurality of fourth lenses, and are focused by any one of a plurality of light-receiving element groups that include a plurality of light-receiving elements.

Abstract: The present disclosure relates to the design of fiber frequency comb lasers with low carrier phase noise. Examples of these low carrier phase noise oscillators can be constructed from both soliton and dispersion compensated fiber lasers via the use of intra-cavity amplitude modulators such as graphene modulators. In low carrier phase noise dispersion compensated fiber frequency comb lasers, graphene and/or bulk modulators can further be used, for example, for phase locking of one comb line to an external continuous wave (cw) reference laser via high bandwidth control of the repetition rate of the comb laser via the graphene modulator. As a result a low phase noise radio frequency (RF) signal can be generated. In some implementations, a frequency comb exhibiting phase noise suppression of at least about 10 dB over a frequency range up to about 100 kHz is provided.

Abstract: To provide a high-density optical interconnect device, information processing device and data transmission method which are able to suppress limitations caused by the widening of light beams and the size of lenses. An optical interconnect unit includes a plurality of first lenses and a plurality of second lenses corresponding to a plurality of light-emitting element groups, and a plurality of light beams emitted from the plurality of light-emitting element groups pass through plurality of first lenses and the plurality of second lenses. The optical interconnect unit also includes a plurality of third lenses and a plurality of fourth lenses, and light beam groups pass through any one of the plurality of third lenses and the plurality of fourth lenses, and are focused by any one of a plurality of light-receiving element groups that include a plurality of light-receiving elements.