A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, one or more proximal-side electrostatic cavities are defined between the VCSEL device and the membrane device and used to displace the mirror to decrease a size of an optical cavity.

A tunable laser that is characterized by including a gain waveguide ACT made of an optically active semiconductor material, and a tunable wavelength filter TWF that selects light of a specific wavelength using current injection, which are integrated on a compound semiconductor substrate S, in which at least one or more of the tunable wavelength filters TWF are formed to select a specific wavelength of light from the light from the waveguide ACT and return the selected specific wavelength of light back to the waveguide ACT, and a semiconductor mixed crystal material constituting the tunable wavelength filter TWF has a strained multiple quantum well structure MQW in which a mixed crystal material ratio changes periodically.

A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, one or more proximal-side electrostatic cavities are defined between the VCSEL device and the membrane device and used to displace the mirror to decrease a size of an optical cavity.

An embodiment provides a beam projector module including: a light source configured to output light; a substrate configured to support the light source; an optical device configured to reduce the light in terms of intensity output to a predetermined space; a frame configured to separate the optical device from the light source by a predetermined distance; an optical substrate configured to attach the optical device thereto and to define a sealed space with the substrate and the frame, the sealed space having internal pressure lower than pressure outside the sealed space; a sensor configured to measure a state of the sealed space; and a processor configured to change an operation mode of the light source depending on a measured value of the sensor.

A synthesizer includes a first resonator mirror, a second resonator mirror, and a gain medium disposed within a laser resonator cavity defined by the first resonator mirror and the second resonator mirror. The synthesizer includes a saturable absorber operationally coupled to the gain medium and having active control such that the saturable absorber is configured to generate a waveform via an injection locking signal to create a mode locking effect, the waveform having a frequency comb defined by dimensions of the gain medium. The synthesizer also includes a crystal electro-optical modulator disposed within the laser resonator cavity. The waveform passes through the modulator to impinge on a photodiode to output an emission RF waveform. Changing the voltage applied to the modulator changes the index of refraction of the modulator, altering an optical path length of the laser resonator cavity to adjust a frequency of the emission RF waveform.

A photonic integrated circuit device includes a lasing cavity for resonating at a plurality of discrete wavelengths and an optical feedback cavity operably coupled to the lasing cavity via a front surface of the lasing cavity. The optical feedback cavity has a reflective element for reflecting light, at least partially, back into the lasing cavity to form a resonant Fabry-Perot cavity between the front surface and the reflective element. The optical feedback cavity includes a variable phase shifting element adapted for receiving an input signal to control a phase shift of light propagating in the optical feedback cavity. The amount of light entering the lasing cavity from the optical feedback cavity is low enough to avoid dynamic instability of the lasing cavity. The reduction in light is obtained using an attenuator.

Laser processing device (100) includes laser oscillator (10) that generates laser light beam (LB), optical fiber (30) that transmits laser light beam (LB), laser head (40) that emits laser light beam (LB) to workpiece (W), and chiller (50) that passes and circulates cooling water through laser oscillator (10) to cool laser oscillator (10). Laser oscillator (10) includes: a plurality of laser diodes; and a base having a cooling water channel therein and having the laser diodes mounted on a surface thereof. Laser processing device (100) is configured to change the incident angle of laser light beam (LB) entering optical fiber (30) by changing the water pressure of the cooling water flowing through the cooling water channel.

Described are various configurations of integrated wavelength lockers including asymmetric Mach-Zehnder interferometers (AMZIs) and associated detectors. Various embodiments provide improved wavelength-locking accuracy by using an active tuning element in the AMZI to achieve an operational position with high locking sensitivity, a coherent receiver to reduce the frequency-dependence of the locking sensitivity, and/or a temperature sensor and/or strain gauge to computationally correct for the effect of temperature or strain changes.

An optical device includes a first reflector; a second reflector; an elastic support unit supporting the second reflector; a piezoelectric element on the elastic support unit; a light emitter configured to emit light having an oscillation wavelength; and circuitry configured to output a signal to apply drive voltage to the piezoelectric element to elastically deform the elastic support unit. The deformation of the elastic support unit changes a distance between the first reflector and the second reflector to change the oscillation wavelength of the light emitted from the light emitter.

Disclosed is a single-photon source emitting light with controllable circular polarization direction. A pillar structure above a semiconductor substrate includes a semiconductor single-quantum-dot structure. A spin injection layer is arranged above the pillar structure. A pulsed voltage is applied between the spin injection layer and the semiconductor substrate to inject a spin-polarized single-carrier from the spin injection layer into the semiconductor single-quantum-dot structure. In response to the injected single-carrier, a single-quantum-dot emits a single-photon with a circular polarization direction corresponding to the spin direction of the injected single-carrier. The polarization controllable single-photon source allows to use magnetic or electrical means to modulate the circular polarization direction of single-photon. The modulation speed by electrical mean can reach up to GHz range.