Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

The present invention provides a multichannel parallel light emitting device comprising a semiconductor cooler, a cold surface of the semiconductor cooler completely covers the area of a hot surface, and when the hot surface and the cold surface are horizontally disposed, a horizontal distance is reserved between the edge of the cold surface and the edge of the hot surface, and a positive electrode and a negative electrode are fixed on a second surface of the cold surface. The semiconductor cooler with the above structure is disposed in a sealed BOX of a BOX package, the bottom surface of the inner wall of the BOX package is provided with a groove for mounting a semiconductor cooler, a hot surface of the semiconductor cooler is fixed at the bottom of the groove, an insulating low thermal conductivity sealing ring is disposed between a lower end of a cold surface of the semiconductor cooler and the BOX package, so that the BOX package, the insulating low thermal conductivity sealing ring and the cold surface of the semiconductor cooler form a closed space, so as to achieve the TEC local hermetic effect, a water-proof film is not required for the TEC, and to ensure the TEC can work in a non-hermetic environment.

This application describes a wavelength-tunable laser apparatus, which reduces complexity of wavelength tuning of a laser. The laser includes a reflective gain unit, an optical phase shifter, a coupler, and a passive filter unit array. Furthermore, an output port of the reflective gain unit is connected to an input port of the optical phase shifter, an output port of the optical phase shifter is connected to an input port of the coupler, a first output port of the coupler is connected to an input port of the passive filter unit array, and a second output port of the coupler is an output port of the laser. The passive filter unit array includes a plurality of passive filter units, where any two of the plurality of passive filter units have different wavelength tuning ranges, and each filter unit has a linearly tunable wavelength.

A non-reciprocal optical assembly for injection locking a laser to a resonator is described. The laser emits a light beam, and the resonator receives the light beam and returns a feedback light beam to the laser such that the feedback light beam causes injection locking. The non-reciprocal optical assembly is interposed between and optically coupled to the laser and the resonator. The non-reciprocal optical assembly includes a first port that receives the light beam from the laser, and a second port that outputs the light beam to the resonator and receives the feedback light beam from the resonator. The first port also outputs the feedback light beam to the laser. The light beam passes through the non-reciprocal optical assembly with a first power loss, and the feedback light beam passes through the non-reciprocal optical assembly with a second power loss (the first power loss differs from the second power loss).

Systems, devices, and methods for narrow waveband laser diodes are described. The conventional coating on the output facet of a laser diode is replaced with a notch filter coating that is reflective of wavelengths within a narrow waveband around the nominal output wavelength of the laser diode and transmissive of other wavelengths. The notch filter coating ensures the laser diode will lase at the nominal wavelength and not lase for wavelengths outside of the narrow waveband. The notch-filtered laser diode provides a narrow waveband output that is matched to the playback wavelength of at least one hologram in a transparent combiner of a wearable heads-up display, and thereby reduces or eliminates display aberrations that can result from wavelength sensitivity of the playback properties of the hologram.

Systems and methods for performing resonator fiber optic gyroscope (RFOG) resonance hopping are described herein. For example, an RFOG includes a fiber optic resonator. The RFOG also includes a plurality of laser sources that each launch a respective laser for propagation within the fiber optic resonator. Further, the RFOG includes a threshold detector that determines when the operation of at least one laser source in the plurality of laser sources exceeds a threshold associated with the operational range of an aspect of the at least one laser source. Additionally, the RFOG includes a hop control logic that adjusts the frequency of at least one laser produced by the at least one laser source one or more resonant modes of the fiber optic resonator such that the aspect of the at least one laser moves away from the threshold towards a nominal value within the operational range.

A wavelength-multiplexed light transmission module according to the present invention includes a plurality of lasers that respectively emit a plurality of laser beams having different wavelengths, a lens radially emitting the plurality of laser beams, a bandpass filter that has a transmission center wavelength which is shorter as an incident angle is larger, and a mirror for reflecting the plurality of laser beams, wherein the plurality of laser beams are incident to the bandpass filter such that the incident angle of a laser beam is larger as the laser beam has a shorter wavelength, whereby the plurality of laser beams are transmitted through the bandpass filter, and an inclination angle of the mirror with respect to the bandpass filter is provided such that the plurality of laser beams transmitted through the bandpass filter are reflected by the bandpass filter and the mirror to be multiplexed with one another.

In one embodiment, a lidar system includes a light source configured to emit an optical signal. The light source includes a seed laser diode configured to produce a seed optical signal and a semiconductor optical amplifier (SOA) configured to amplify the seed optical signal to produce an amplified seed optical signal, where the emitted optical signal includes the amplified seed optical signal. The light source further includes an electronic driver configured to supply electrical current to the seed laser diode and electrical current to the SOA. The lidar system also includes a receiver configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Example embodiments disclose a tunable optical pair source (TOPS) configured to generate first and second output optical beams having respective first and second frequencies that are phase locked with each other. The TOPS may include a first laser, such as a tunable laser, configured to generate a first laser beam, a radio frequency (RF) oscillator configured to transmit an RF reference signal, a beam splitter in optical communication with the first laser, and an electro-optic modulator configured to modulate the second split beam with the RF reference signal to form a modulated beam having a first sideband comb comprising a plurality of harmonics. Additionally, the TOPS may include an optical filter configured to receive the modulated beam and output a filtered optical beam, and a second laser configured to generate a second laser beam at the second frequency, the second laser being configured to receive the filtered optical beam as a seed.

The invention relates to a laser system comprising a laser light source (1) that emits laser radiation during operation of the laser system, a modulation means (2) that brings about modulation of the laser radiation emitted by the laser light source (1) such that the spectrum of the laser radiation comprises a carrier (14) and two sidebands (13, 15) that are symmetrically distributed around the carrier, and at least one optical amplifier (5) that amplifies the radiation emitted by the laser light source (1). The invention proposes that an optical filter (4) be provided in the beam path of the laser radiation, upstream of the optical amplifier (5), which filter is intended for removing the spectral portion of the laser radiation at the frequency of one of the two sidebands (13). The laser system is suitable inter alia for generating an artificial guide star (laser guide star) for astronomical telescopes comprising adaptive optics. The invention furthermore relates to a method for generating single-sideband modulated laser radiation.