Embodiments of the disclosure provide a laser beam generation system. The laser beam generation system includes a first laser chip configured to generate a first polarized laser beam and a second laser chip configured to generate a second polarized laser beam. The laser beam generation system also includes a polarizer configured to combine the first polarized laser beam and the second polarized laser beam to generate a third laser beam.

A tunable multi-mode laser is configured to generate a multi-mode optical signal at a tuned wavelength. The laser includes a semiconductor optical gain region, a feedback region, and a phase modulation region between the gain and feedback regions. Each of the regions may be monolithically integrated. A feedback loop is coupled to the tunable laser to receive the optical signal and includes at least one delay line. The delay line may also be monolithically integrated. An output of the delay line is fed back to the tunable multi-mode laser in order to provide at least one of self-injection locking and self-phase locked looping for the multi-mode tunable laser. Each of the optical gain region and phase modulation region of the laser is biased by the output of the delay line in order to reduce phase drift of the optical signal.

A laser device includes a laser oscillator emitting a laser beam, and an optical unit receiving the laser beam and emitting the laser beam to outside. The optical unit includes: a partially transmissive mirror reflecting a part of the laser beam toward the outside while transmitting a remaining part of the laser beam; a diffusion plate diffusing the laser beam passed through the partially transmissive mirror and deflecting the laser beam in a predetermined direction, at a predetermined diffusion angle; and a photodiode receiving the laser beam deflected by the diffusion plate, and outputting an electric signal. The laser device is configured such that deviation of an optical axis of the laser beam is monitored based on an output signal of the photodiode.

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 method, apparatus, and system for an external cavity laser with a Michelson Interferometer.

A laser for a distributed fiber sensing system may have a frequency discriminator integrated with the laser. The laser may be an external cavity laser, with at least a portion of the laser cavity on a planar lightwave circuit, which also includes the frequency discriminator.

A time-of-flight (ToF) transmitter with self-stabilized optical output phase with minimal overhead is described, where the transmitter may either function as a slave in that the laser pulse phase and width can be controlled by the master ToF receiver, or it can function as a master where the laser control pulse is generated on the same chip or a companion chip. When the ToF transmitter functions as a slave and receives the laser pulse control signal, the techniques of this disclosure can transform the receive path and the pre-driver circuit into part of a delay locked loop (DLL).

Narrow-optical linewidth laser generation devices and methods for generating a narrow-optical linewidth laser beam are provided. One narrow-optical linewidth laser generation devie includes a single-wavelength mirror or multiwavelength mirror (for comb lasers) formed from one or more optical ring resonators coupled with an optical splitter. The optical splitter may in turn be coupled with a quantum dot optical amplifier (QDOA), itself coupled with a phase-tuner. The phase tuner may be further coupled with a broadband mirror. The narrow-optical linewidth laser beam is generated by using a long laser cavity and additionally by using an integrated optical feedback.

An apparatus and method for calculating the frequency of the light.

There is disclosed a DBR laser and a method of use. The DBR laser comprises a phase section in a cavity of the DBR laser and configured to adjust an optical path length of the cavity. A DBR section comprises a frequency tuning system configured to adjust a Bragg frequency of the DBR section. A detector is configured to detect laser light transmitted through the DBR section. A controller is configured: to cause the phase section to apply a dither to the optical path length of the cavity or cause the frequency tuning system to apply a dither to the Bragg frequency of the DBR section; to use the detector to monitor intensity of light transmitted from the laser cavity via the DBR section during application of the dither; to determine a deviation from longitudinal mode centre operation on the basis of the monitored intensity; and to cause the frequency tuning system to adjust the Bragg frequency of the DBR section in order to reduce said deviation, or cause the phase section to adjust the optical path length of the cavity in order to reduce said deviation.