An optical source is described. This optical source includes a semiconductor optical amplifier, with a semiconductor other than silicon, which provides a gain medium. In addition, a photonic chip, optically coupled to the semiconductor optical amplifier, includes: an optical waveguide that conveys the optical signal; and a pair of ring-resonator modulators that modulate the optical signal. Furthermore, the pair of ring-resonator modulators is included within an optical cavity in the optical source. For example, the optical cavity may be defined by a reflective coating on one edge of the semiconductor optical amplifier and a reflector on one end of the optical waveguide. Alternatively, the optical cavity may be defined by reflectors on ends of the optical waveguide.

Systems and methods for a tunable radio frequency synthesizer utilizing optical frequency combs are provided. In one embodiment, an RF signal generator comprises: an SBS pump laser segment including a first and second SBS pump laser each generating SBS laser light at different respective frequencies; a TE/TM dual comb resonator comprising a comb optical resonator coupled to the first and second SBS pump lasers, wherein the comb optical resonator generates a pair of counter-propagating optical frequency combs of different polarities from the SBS laser light; a filter resonator segment configured to provide feedback to the TE/TM dual comb resonator to lock a relative position of the pair of counter-propagating optical frequency combs, the filter resonator comprising a tunable optical filter to output a discrete tuned RF signal output based on a comb line pair that includes a single comb line from each of the pair of counter-propagating optical frequency combs.

A beam combining device and method for a Bragg grating external-cavity laser module has a plurality of side by side light-emitting modules that use a Bragg grating to perform wavelength locking. Output light of the modules is incident to a beam combining element after passing through a focusing optical element for beam combining, and light subjected to beam combining is reflected partially and transmitted partially under the effect of a light splitting element. A part is incident into a dispersion element at a diffraction angle of the element. Parallel light is formed under the effect of a conversion optical element. Spots of the light beams of corresponding wavelengths of the light-emitting modules are formed on an image acquisition mechanism. Whether the wavelengths of the corresponding light-emitting modules are locked is determined by whether there is a deviation between preset spots and spots formed by the module on the acquisition mechanism.

In various embodiments, laser apparatuses include thermal bonding layers between various components and sealing materials for preventing or retarding movement of thermal bonding material out of the thermal bonding layers.

The present invention provides one or more injection-lockable whistle-geometry semiconductor ring lasers, which may be cascaded, that are integrated on a common silicon-on-insulator (SOI) substrate with a single-frequency semiconductor master laser, wherein the light output from the semiconductor master laser is used to injection-lock the first of the semiconductor ring lasers. The ring lasers can be operated in strongly injection-locked mode, while at least one of them is subjected to direct injection current modulation.

An asymmetric whispering gallery mode resonator device is described. The resonator device includes an asymmetric whispering gallery mode resonator disk (e.g., transparent material, electrooptic material). The resonator disk includes an axial surface along a perimeter of the resonator disk, a top surface, and a bottom surface. A first midplane passes through the axial surface dividing the axial surface into symmetrical halves. The top surface and the bottom surface are substantially parallel, and a second midplane is substantially equidistant between the top surface and the bottom surface. The first midplane and the second midplane are non-coextensive. The asymmetric whispering gallery mode resonator disk can further include a first chamfered edge between the top surface and the axial surface, and a second chamfered edge between the bottom surface and the axial surface. Moreover, the resonator device includes a first electrode on the top surface and a second electrode on the bottom surface.

A multisection digital supermode-distributed Bragg reflector (MSDS-DBR) comprising: a plurality P of digital supermode Bragg reflector (DS-DBR) grating sections arranged along a waveguide; wherein each DS-DBR grating section is configured to pass or reflect light over a given spectral region, the given spectral region being different from the spectral regions of the other DS-DBR grating sections; wherein each DS-DBR grating section comprises a plurality M of grating sub-regions, each sub-region corresponding to a spectral sub-band within the spectral region of the DS-DBR grating section, and wherein each grating sub-region includes a positive electrical contact and a negative electrical contact; said grating sub-region being configured to pass or reflect light of its spectral sub-band when an electrical bias is provided between its positive and negative electrical contacts.

According to an aspect, an optical system includes a laser diode configured to emit optical signals and at least two size-switchable broken racetrack ring resonators optically coupled to an optical waveguide, where each broken racetrack ring resonator is configured to exhibit a resonant wavelength. The optical system also includes a tuning arrangement associated with the broken racetrack ring resonators, where the tuning arrangement includes a micro electro-mechanical system (MEMS) or nano electro-mechanical system (NEMS) actuator mechanically coupled to a first portion of a first one of the broken racetrack ring resonators and configured to mechanically move the first portion so as to change the resonant wavelength of the first one of the broken racetrack ring resonators.

An optical source is described. This optical source includes a semiconductor optical amplifier (with a semiconductor other than silicon) that provides an optical gain medium and that includes a reflector. Moreover the hybrid external cavity laser includes a photonic chip with: an optical waveguide that conveys an optical signal output by the semiconductor optical amplifier; and a ring resonator, having a resonance wavelength, which reflects at least a resonance wavelength in the optical signal, where the reflector and the ring resonator define an optical cavity. Furthermore, the photonic chip includes: a thermal-tuning mechanism that adjusts the resonance wavelength; a photo-detector that measures an optical power output by the ring resonator; and control logic that adjusts the temperature of the ring resonator based on the measured optical power to lock a cavity mode of the optical cavity to a carrier wavelength.

The disclosed embodiments provide a tunable laser that includes a set of M reflective silicon optical amplifiers (RSOAs) and a set of N narrow-band reflectors. It also includes a silicon-photonic optical switch, having M amplifier ports, which are coupled through a set of M optical waveguides to the set of M RSOAs, and N reflector ports, which are coupled to the set of N narrow-band reflectors. The tunable laser also includes a switching mechanism that facilitates coupling at least one selected amplifier port from the M amplifier ports with a selected reflector port from the N reflector ports, thereby causing an RSOA coupled to the selected amplifier port to form a lasing cavity with a narrow-band reflector coupled to the selected reflector port. The tunable laser also includes a laser output, which is optically coupled to the lasing cavity.