A passively, Q-switched laser is described. The laser may operate at an eye-safe lasing wavelength of 1.34 microns and use a gain element of Nd:YVO.sub.4 and a saturable absorber element of V:YAG with a space separating the gain element and saturable absorber element. The Q-switched laser is pumped by a grating stabilized laser diode. The laser may be used in laser ranging applications.

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.

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 may include a diode-pumped solid-state laser oscillator configured to output a pulsed laser beam, a modulator configured to modify an energy and a temporal profile of the pulsed laser beam, and an amplifier configured to amplify an energy of the pulse laser beam. A modified and amplified beam to laser peen a target part may have an energy of about 5J to about 10 J, an average power (defined as energy (J) x frequency (Hz)) of from about 25 W to about 200 W, with a flattop beam uniformity of less than about 0.2. The diode-pumped solid-state oscillator may be configured to output a beam having both a single longitudinal mode and a single transverse mode, and to produce and output beams at a frequency of about 20 Hz.

Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

A gain medium is pumped by a source. An optical wave passes through a photonic integrated circuit (PIC) that comprises: a substrate comprising Silicon, a plurality of photonic structures, an input port coupling an optical wave into a waveguide formed in the PIC, and an output port coupling an optical wave out of a waveguide formed in the PIC. Propagation of an optical wave circulating around a closed path of a laser ring cavity is limited using an optical isolator such that, when the pump source exceeds a lasing threshold, the optical wave propagates in a single direction through the gain medium and the PIC. From output coupler, an output that is provided that comprises a fraction of the power of an optical wave that is incident upon the output coupler, and remaining power of the optical wave is redirected around the closed path of the laser ring cavity. The fraction can be greater than 0.5.

A passively, Q-switched laser operating at an eye safe wavelength of between 1.2 and 1.4 microns is described. The laser may operate at a lasing wavelength of 1.34 microns and use a gain element of Nd:YVO.sub.4 and a saturable absorber element of V:YAG. The systems and methods to produce short pulses having a pulse duration less than 1 ns and high energy pulses having pulse energies greater than 2 μJ are described.

A multi-stage thulium-doped (Tm-doped) fiber amplifiers (TDFA) is based on the use of single-clad Tm-doped optical fiber and includes a wavelength conditioning element to compensate for the nonuniform spectral response of the initial stage(s) prior to providing power boosting in the output stage. The wavelength conditioning element, which may comprise a gain shaping filter, exhibits a wavelength-dependent response that flattens the gain profile and output power distribution of the amplified signal prior to reaching the output stage of the multi-stage TDFA. The inclusion of the wavelength conditioning element allows the operating bandwidth of the amplifier to be extended so as to encompass a large portion of the eye-safe 2 μm wavelength region.

A frequency modulated, continuous wave (FMCW) laser using a microchip gain medium, an optical coupling element, and a tuning element is described. The laser may be part of a coherent laser ranging system.

A laser system includes a resonant laser cavity configured to output a laser signal. The system also includes a utility waveguide configured to receive the laser signal from the laser cavity. The utility waveguide includes a perturbation region that is external to the laser cavity and receives the laser signal from the laser cavity and outputs a laser beam. The perturbation region includes one or more perturbation structures that each causes one or more perturbation(s) in the index of refraction of the utility waveguide. The perturbation structures are selected to provide optical feedback to the resonant laser cavity such that a power versus wavelength distribution in the laser beam is different from the power versus wavelength distribution that would be in the laser signal in the absence of the perturbation structures.