Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuitry for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations.

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.

A handheld LIBS device and method includes a laser assembly producing two pulsed single spatial mode output beams and a focusing optic which combines the two pulsed single spatial mode output beams at a focal point at a sample. The laser assembly includes a laser assembly housing with an output coupler window for the two pulsed single spatial mode output beams, a gain medium in the laser assembly housing between the output coupler window and an adjustable prism mount in the laser assembly housing holding a prism configured to establish two light paths through the gain medium, a source in the laser assembly housing providing pump energy to the gain medium, and a Q-switch positioned between the prism and the gain medium.

A handheld LIBS device and method includes a laser assembly producing two pulsed single spatial mode output beams and a focusing optic which combines the two pulsed single spatial mode output beams at a focal point at a sample. The laser assembly includes a laser assembly housing with an output coupler window for the two pulsed single spatial mode output beams, a gain medium in the laser assembly housing between the output coupler window and an adjustable prism mount in the laser assembly housing holding a prism configured to establish two light paths through the gain medium, a source in the laser assembly housing providing pump energy to the gain medium, and a Q-switch positioned between the prism and the gain medium.

A beam positioner can be broadly characterized as including a first acousto-optic (AO) deflector (AOD) operative to diffract an incident beam of linearly polarized laser light, wherein the first AOD has a first diffraction axis and wherein the first AOD is oriented such that the first diffraction axis has a predetermined spatial relationship with the plane of polarization of the linearly polarized laser light. The beam positioner can include at least one phase-shifting reflector arranged within a beam path along which light is propagatable from the first AOD. The at least one phase-shifting reflector can be configured and oriented to rotate the plane of polarization of light diffracted by the first AOD.

The present disclosure is directed to systems and methods for controlling a center wavelength. In one example, a method includes estimating a center wavelength error. The method also includes determining a first actuation amount for a first actuator controlling movement a first prism based on the estimated center wavelength error. The method also includes actuating the first actuator based on the actuation amount. The method also includes determining whether the first prism is off-center. The method also includes, in response to determining that the first prism is off-center, determining a second actuation amount for the first actuator and determining a third actuation amount for a second actuator for controlling movement of a second prism. The method also includes actuating the first actuator and the second actuator based on the second and third actuation amounts, respectively. The method finds application in multi-focal imaging operations.

Integrated wavelength selectors are described. The wavelength selector may include silicon nitride ring resonator disposed vertically between a heater and a temperature sensor. The temperature sensor may be formed of silicon in some embodiments. The wavelength selector may be coupled to the output port of a tunable laser, or may be disposed within a laser cavity.

A spectroscopic laser sensor based on hybrid III-V/IV system-on-a-chip technology. The laser sensor is configured to either (i) be used with a fiber-optic probe connected to an intravenous/intra-arterial optical catheter for direct invasive blood analyte concentration level measurement or (ii) be used to measure blood analyte concentration level non-invasively through an optical interface attached, e.g., to the skin or fingernail bed of a human. The sensor includes a III-V gain-chip, e.g., an AlGaInAsSb/GaSb based gain-chip, and a photonic integrated circuit, with laser wavelength filtering, laser wavelength tuning, laser wavelength monitoring, laser signal monitoring and signal output sections realized on a chip by combining IV-based semiconductor substrates and flip-chip AlGa1-nAsSb/GaSb based photodetectors and embedded electronics for signal processing. Embodiments of the invention may be applied for real-time monitoring of critical blood analyte concentration levels such as lactates, urea, glucose, ammonia, albumin, etc.

A discrete wavelength tunable laser having an optical cavity which comprises: a reflective semiconductor optical amplifier (SOA); a demultiplexer (Demux) having a single input and a plurality of outputs, the Demux configured to receive the output of the SOA and to produce a plurality of fixed spectral passbands within the gain bandwidth of the SOA; one or more tunable distributed Bragg reflector(s) (DBR(s)) arranged to receive the outputs of the Demux, each tunable DBR configured to select a reflective spectral band within the gain bandwidth of the SOA upon application of a bias current; wherein the SOA forms the back end mirror of the optical cavity; the one or more tunable DBRs form the front end mirror of the optical cavity; and wherein the lasing channel of the discrete wavelength tunable laser is chosen by the overlap of the selected reflective spectral band of one of the one or more tunable DBRs with a fixed spectral passband of the Demux.

A femtosecond pulse laser apparatus includes a pump light source configured to provide a pump light, a gain medium configured to obtain a gain of a laser light using the pump light, a first curved mirror and a second curved mirror, which are provided at both sides of the gain medium, an output mirror configured to transmit a portion of the laser light and reflect the other portion of the laser light to the gain medium, a mode locking portion configured to generate a femtosecond pulse of the laser light, and an acoustic wave generator configured to provide an acoustic wave into the gain medium so as to adjust self-phase modulation of the laser light.