A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

An optical waveguide structure includes a lower cladding layer positioned on a substrate; an optical guide layer positioned on the lower cladding layer; an upper cladding layer positioned on the optical guide layer; and a heater positioned on the upper cladding layer. The lower cladding layer, the optical guide layer, and the upper cladding layer constitute a mesa structure. The optical guide layer has a lower thermal conductivity than the upper cladding layer. An equation “W.sub.wg≤W.sub.mesa≤3×W.sub.wg” is satisfied, wherein W.sub.mesa represents a mesa width of the mesa structure, and W.sub.wg represents a width of the optical guide layer. The optical guide layer occupies one-third or more of the mesa width in a width direction of the mesa structure.

A pluggable optical connector is configured to be insertable into and removable from an optical communication apparatus, and to be capable of communicating a modulation signal and a data signal with the optical communication apparatus. A wavelength-tunable light source is configured to output an output light and a local oscillation light. An optical transmission unit is configured to output an optical signal generated by modulating the output light in response to the modulation signal. An optical reception unit is configured to demodulate an optical signal received by using the local oscillation light to the data signal. Pluggable optical receptors are configured in such a manner that an optical fiber is insertable into and removable from the pluggable optical receptors, and configured to be capable of outputting the optical signal to the optical fiber and transferring the optical signal received thorough the optical fiber to the optical reception unit.

A laser system for generating a narrow linewidth semiconductor light beam includes a substrate, a gain chip affixed on the substrate and configured to amplify light beam, and an optical feedback photonic chip affixed on the substrate, optically coupled to the gain chip, and configured to output light beam, which has a narrow linewidth around a resonant frequency of the optical feedback photonic chip, to the gain chip.

A device comprises three elements, realized as photonic integrated circuits. The first element comprises a tunable semiconductor laser emitting light at a laser output wavelength. The second element comprises a wavelength selective element, coupled to the first element. The third element comprises N photodetectors where N>=2, coupled to the second element. Light coupled into the second element from the first element is de-multiplexed by the wavelength selective element such that a ratio of light power coupled from the second element into one of the N photodetectors to light power coupled from the second element into another one of the N photodetectors is a function of the laser output wavelength. The responses of the N photodetectors facilitate at least one of measurement and control of the laser output wavelength.

The present invention relates to evanescently coupling whispering gallery mode optical resonators having a liquid coupling as well as methods of making and using same. The aforementioned evanescently coupling whispering gallery mode optical resonators having a liquid couplings provide increased tunability and sensing selectivity over current same. The aforementioned. Applicants' method of making evanescent-wave coupled optical resonators can be achieved while having coupling gap dimensions that can be fabricated using standard photolithography. Thus economic, rapid, and mass production of coupled WGM resonators-based lasers, sensors, and signal processors for a broad range of applications can be realized.

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.

A wavelength tunable light source includes: a common wavelength filter that has periodic transmission peak wavelengths or reflection peak wavelengths and is commonly used for a plurality of channels; a wavelength tunable filter that is coupled to the common wavelength filter and has a one-input and multiple-output configuration which has a plurality of output ports, and that has a plurality of transmission peak wavelengths corresponding to the plurality of channels at the plurality of output ports; and a plurality of gain media optically coupled to the plurality of output ports of the wavelength tunable filter, wherein a plurality of laser cavities that perform laser oscillation at a plurality of different wavelengths are formed between the common wavelength filter and the plurality of gain media.

A laser system includes: a first laser element constituting one end of a first external resonator; a second laser element constituting one end of a second external resonator; a diffractive optical element to which a first beam group and a second beam group enter; a partially reflective element that constitutes an opposite end of the first external resonator and an opposite end of the second external resonator, reflects a part of the first beam and a part of the second beam, and transmits the remainder of the first beam and the remainder of the second beam; and a beam deflection element that deflects the second beam emitted from the diffractive optical element toward the partially reflective element.

An integrated optical linewidth reduction system based on optical feedback and a low-speed electronic control loop to control the optical feedback. Light is tapped and reflected back to the laser with an amplitude, phase or both amplitude and phase adjustment such that the linewidth of the laser is lower than the free-running laser linewidth. The amplitude of the feedback signal may be controlled using an optical attenuator. The phase of the feedback signal may be controlled using a phase shifter. The amplitude of the optical feedback may be monitored by means of a filter and a photodetector, or just a photodetector. The amplitude and/or phase of the optical feedback is monitored by means of a frequency/phase noise discriminator. The phase shifter can be an endless phase shifter