Embodiments of the present disclosure are directed to multi-wavelength laser generator may produce light with a frequency comb having equally spaced frequency lines. In various embodiments, the laser generator includes first, a semiconductor gain element is used to provide gain to the laser being generated. Second, a ring resonator filter, or ring filter, is used to select the wavelength comb spacing. Third, a narrow-band DBR or narrow-band mirror is used to select the number of wavelengths that lase. Fourth, a wide-band or narrow-band mirror is used to provide optical feedback and to form the optical cavity. Fifth, a phase tuner section is used to align the cavity modes with the ring resonances (i.e. the ring filter modes) in order to reduce or minimize the modal loss. Other embodiments may be described and/or claimed.

A tunable laser includes a housing having a sealable accommodating cavity, an optical interface and an electrical interface disposed on the housing, a tunable semiconductor laser apparatus, a splitter component, and a photodetector. The tunable semiconductor laser apparatus is disposed in the accommodating cavity for emitting an optical signal whose wavelength is tunable. An electrical signal inputted through the electrical interface controls the tunable semiconductor laser apparatus to emit the optical signal. The optical signal is outputted through the optical interface. The splitter component and the photodetector are disposed outside the housing. The optical signal is split into at least two beams of light by the splitter component after the optical signal is outputted through the optical interface. The photodetector is configured to receive one of the beams of light to monitor the optical signal emitted by the tunable semiconductor laser apparatus.

Disclosed herein are multi-layered optically active regions for semiconductor light-emitting devices (LEDs) that incorporate intermediate carrier blocking layers, the intermediate carrier blocking layers having design parameters for compositions and doping levels selected to provide efficient control over the carrier injection distribution across the active regions to achieve desired device injection characteristics. Examples of embodiments discussed herein include, among others: a multiple-quantum-well variable-color LED operating in visible optical range with full coverage of RGB gamut, a multiple-quantum-well variable-color LED operating in visible optical range with an extended color gamut beyond standard RGB gamut, a multiple-quantum-well light-white emitting LED with variable color temperature, and a multiple-quantum-well LED with uniformly populated active layers.

Techniques and circuitry for a semiconductor laser with enhanced lasing wavelengths stabilization are described. A semiconductor laser can generate an optical signal (e.g., single or multi-wavelength), for use in a Dense Wavelength Division Multiplexing (DWDM) interconnect system. The stabilization circuitry can include temperature sensor circuitry that measures an operational temperature of the semiconductor laser, and a feedback controller that can determine a temperature-induced wavelength shift that may be experienced by the multi-wavelength optical signal based on the laser's temperature. The feedback controller is also configured to generate a compensation signal that is determined to cause a complimentary shift in the multi-wavelength optical signal, where the complimentary shift can compensate for the temperature-induced wavelength shift. An integrated MOS capacitor of the laser can be charged by the signal in a manner that effectuates the complimentary shift and tunes the multi-wavelength optical signal to compensate for temperature-induced shift, thereby enhancing stabilization.

An optical frequency comb setup including a semiconductor cascade laser drivable by a laser driver, emitting a laser beam through an end facet of the semiconductor cascade laser with a frequency comb with at least two given individual emission frequencies, repetition frequency, carrier envelope offset frequency shows improved comb stability and/or comb formation and/or comb bandwidth. This is achieved by an external cavity added outside of the cavity of the semiconductor cascade laser, having a reflective element with a mirror surface reflecting the at least two individual emission frequencies being arranged in a relative distance to the end facet allowing to adapt repetition frequency and/or carrier envelope offset frequency and/or the dispersion seen by the light in the optical frequency comb setup.

A micro disk laser having a greater strength of oscillation in one direction than in another direction and unidirectionally oscillating includes a micro disk having an oval shape corresponding to a modified ellipse obtained by changing a length of a short axis of an ellipse according to a position of a long axis while lengths of first and second side portions of the long axis are fixed in the ellipse, the ellipse having the long axis and the short axis having a different length than the long axis.

A resonator is provided having a waveguide with a first boundary, a second boundary parallel to the first boundary, a first end, a second end, and a waveguide cavity at least partly between the first boundary and the second boundary. A first grating, having a period of distance a, is at the first boundary of the waveguide, and a second grating, having a period of distance a, is at the second boundary of the waveguide. The first and second boundaries are separated by a constant distance d. The first boundary may have a periodic profile aligned with a periodic profile of the second boundary. The periodic profile of the first boundary and the second boundary may be a sinusoidal profile, a square profile, or profile of another shape. The resonator may be suitable for use in a distributed feedback laser.

Examples disclosed herein relate to multi-wavelength semiconductor comb lasers. In some examples disclosed herein, a multi-wavelength semiconductor comb laser may include a waveguide included in an upper silicon layer of a silicon-on-insulator (SOI) substrate. The comb laser may include a quantum dot (QD) active gain region above the SOI substrate defining an active section in a laser cavity of the comb laser and a dispersion tuning section included in the laser cavity to tune total cavity dispersion of the comb laser.

The present disclosure describes broadband optical emission sources that include a stack of semiconductor layers, wherein each of the semiconductor layers is operable to emit light of a different respective wavelength; a light source operable to provide optical pumping for stimulated photon emission from the stack; wherein the semiconductor layers are disposed sequentially in the stack such that a first one of the semiconductor layers is closest to the light source and a last one of the semiconductor layers is furthest from the light source, and wherein each particular one of the semiconductor layers is at least partially transparent to the light generated by the other semiconductor layers that are closer to the light source than the particular semiconductor layer. The disclosure also describes various spectrometers that include a broadband optical emission device, and optionally include a tuneable wavelength filter operable to allow a selected pass through.

A semiconductor laser tuned with an acousto-optic modulator. The acousto-optic modulator may generate standing waves or traveling waves. When traveling waves are used, a second acousto-optic modulator may be used in a reverse orientation to cancel out a chirp created in the first acousto-optic modulator. The acousto-optic modulator may be used with standing-wave laser resonators or ring lasers.