A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.

A system includes a master oscillator configured to generate a first optical beam and a beam controller configured to modify the first optical beam. The system also includes a PWG amplifier configured to receive the modified first optical beam and generate a second optical beam having a higher power than the first optical beam. The second optical beam has a power of at least about ten kilowatts. The PWG amplifier includes a single laser gain medium configured to generate the second optical beam. The system further includes a feedback loop configured to control the master oscillator, PWG amplifier, and beam controller. The feedback loop includes a laser controller. The laser controller may be configured to process wavefront information or power in bucket information associated with the second optical beam to control an adaptive optic or perform a back-propagation algorithm to provide wavefront correction at an output of the PWG amplifier.

A fiber optic assembly includes: a gain fiber configured to output signal light; a first taper configured to expand the signal light output by the gain fiber; and a reversing prism configured to receive counter-pumping light and output the counter-pumping light into the first taper. The first taper is further configured to direct the counter-pumping light towards the gain fiber.

A kind of all-solid-state high-power slab laser based on phonon band-edge emission, which is comprised of a pumping source, a focusing system, a resonant cavity and a self-frequency-doubling crystal; the said self-frequency-doubling crystal is a Yb-doped RECOB crystal cut into slab shape along the direction of the crystal's maximum effective nonlinear coefficient of its non-principal plane; by changing the cutting direction of the crystal, the phase matching of different wavelengths is realized, thus realizing laser output at the band of 560-600 nm; the said pumping source is a diode laser matrix with a wavelength of 880 nm-980 nm; the input cavity mirror and the output cavity mirror are coated with films to obtain laser output at the band of 560-600 nm; the two large faces of the said self-frequency-doubling crystal is cooled by heat sink and located between the input cavity mirror and the output cavity mirror.

A voltage-controlled oscillator generates a VCO output signal at frequency f.sub.M. A dual optical-frequency source generates optical signals at frequencies v.sub.1S and v.sub.2S. An electro-optic frequency divider (EOFD) generates multiple optical sidebands spaced by f.sub.M, and from two sidebands generates a beat signal at beat frequency f. A first control circuit generates an error signal from the beat signal and a first reference signal at frequency f.sub.REF1, and couples the VCO and the EOFD in a negative feedback arrangement that stabilizes the output frequency f.sub.M. A second control circuit generates an error signal from the frequency-divided output signal and a second reference signal at frequency f.sub.REF2, and couples the VCO and one or both of the dual source or the first reference signal in a negative feedback arrangement that stabilizes, or compensates for fluctuations of, a difference frequency v.sub.2Sv.sub.1S.

An assembly is used with an amplifier that amplifies light using source light, pump light, and a doped fiber. The assembly has a plurality of ports, including a first port for input of the source light, a second port for input of the pump light, a third port for output to the doped fiber, a fourth port for input from the doped fiber, and a fifth port for amplified output. A birefringent device in optical communication with each of the ports is configured to refract o-light and e-light components of the light passing therethrough with different refractive indices. For the first and fourth ports, a first half-wave plate in optical communication through the birefringent device is configured to rotate polarization of the light passing therethrough with a first rotation. For the second port, a second half-wave plate in optical communication through the birefringent device is configured to rotate polarization of the light passing therethrough with a second rotation different from the first polarization. A lens is used to focus the light, and an optical filter in optical communication with the lens is configured to reflect the pump light back to the lens and being configured to pass the source light. A rotator in optical communication with the lens is configured to rotate polarization of the light passing therethrough with a third rotation. The third rotation is half of the first rotation, and the first rotation is half of the second rotation. Finally, a wedge reflector in optical communication with the rotator is configured to reflect the light incident thereto. The source light and the pump light are combined and communicated from the second port for output to the doped fiber. Meanwhile, amplified light from the doped fiber is received at the fourth port and is communicated to the amplified output. Reverse light from the amplified output can be isolated from reaching the doped fiber, and reverse source light from the doped fiber can be isolated from reaching the source port.

A laser in an embodiment of the present invention is disclosed that includes a laser pump source, a pump-beam coupler (PBC) coupled with the laser pump source, a laser gain medium coupled with the PBC, a second-harmonic generator (SHG) coupled with the laser gain medium; and an output coupler coupled with the SHG.

A laser in an embodiment of the present invention is disclosed that includes a laser pump source, a pump-beam coupler (PBC) coupled with the laser pump source, a laser gain medium coupled with the PBC, a second-harmonic generator (SHG) coupled with the laser gain medium; and an output coupler coupled with the SHG.

An optical device includes: a base; a light emitting device arranged on the base and configured to output a laser beam; a plurality of optical parts arranged on the base and configured to transmit the laser beam output from the light emitting device to an optical fiber to couple with the optical fiber, the plurality of optical parts including a first optical part and a second optical part; and a shielding portion arranged on the base and configured to shield stray light reflected on the second optical part so as to avoid the stray light from being irradiated to the first optical part.

The passively q-switched diode end-pumped solid-state laser is used the gain medium made of Er:Yb doped crystal and the Q-switch made of Co.sup.2+:MgAl.sub.2O.sub.4 crystal. The optical elements are optimally designed for the resonator to achieve pulse energy in a range 0.5 mJ?E?2 mJ with the pulse width in a range of 4 ns-15 ns. The resonator is appropriate to use in laser rangefinders, target designator, and other products in military and civilian applications.