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.

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

An apparatus is provided, the apparatus comprising: (i) a diode-pumped solid-state laser oscillator configured to generate a pulsed laser beam having predefined beam characteristics corresponding to a current setting selection of a controller; and (ii) an amplifier configured to amplify an energy and modify a beam profile of the pulse laser beam. A beam detector is coupled to the generated beam to monitor a combination of: (i) a beam pulse width; (ii) a beam diameter; and (iii) an energy level, and generates an error signal to be sent back as a feedback signal to the controller. The controller configures the current source to output a correction current to tune the DPSSL oscillator, the wave plate, and the first polarizer to rotate a correction polarization angle and adjust the energy amplification or temporal profile to within a defined performance tolerance.

In one aspect, a device is disclosed that includes one or more input ports structured to receive a pumping light at a pumping wavelength and a signal light at a signal wavelength, and one or more output ports structured to output light including an amplified signal light at the signal wavelength and a second harmonic idler light. The device includes a nonlinear optical material to mix the pumping light and the signal light and to cause nonlinear conversion of the pumping light into the amplified signal light and generate an idler light at an idler wavelength. The nonlinear optical material is further structured to convert the idler light into the second harmonic idler light which eliminates the idler light at the one or more output ports and prevents back-conversion of the amplified signal light and idler light to the pumping wavelength.

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 position of the resonator axial mode spectrum relative to a gain peak of the gain element is controlled to yield desired characteristics in the laser output.

A single-frequency laser apparatus comprises a mirror and a volume Bragg grating (VBG) reflector defining a laser cavity therebetween and an optical gain material for emitting and amplifying an intra-cavity beam in the laser cavity. The optical gain material comprises a transition-metal doped crystal such as a crystal doped with transition-metal ions selected from one or more of Ti.sup.3+ ions, Cr.sup.2+ ions, Cr.sup.3+ ions or Cr.sup.4+ ions. A reflectivity spectrum of the VBG reflector and an optical length of the laser cavity are selected so that a beam output from the laser cavity is a single-frequency output beam and/or includes only one longitudinal mode of the laser cavity. The laser apparatus may provide a robust, compact, low cost, high-power wavelength adjustable (from approximately 650 to 950 nm), narrow linewidth (<100 kHz), single frequency laser source which is suitable for a wide range of applications from laser sensing, spectroscopy, and high precision frequency metrology sectors.

A Raman pumping device (10) for amplifying a data optical signal in a fiber optic transmission system, comprising first and second ports (12a, 12b) through which the data optical signal may respectively enter and exit the Raman pumping device (10), a Raman pump source (14) for generating a Raman pump signal, and at least one combiner (16) for combining the Raman pump signal with the data optical signal. The Raman pumping device (10) allows for selectively combining the Raman pump signal generated by the same Raman pump source (14), or at least parts of the same Raman pump source (14) codirectionally or counterdirectionally with the data optical signal.

Provided are a time and frequency control method and system for optical comb. The method includes: controlling an optical comb measuring system to start and to generate an optical comb; obtaining monitoring data, wherein the monitoring data comprises a working temperature, a mode-locked frequency and a light pump power, wherein the mode-locked frequency comprises a repetition frequency and a carrier envelope phase locked at the end of starting the optical comb measuring system; determining whether an offset of the mode-locked frequency exceeds a self-feedback adjustment range of a hardware adjustment circuit; and in response to any of the repetition frequency and the carrier envelope phase exceeds the self-feedback adjustment range, adjusting the working temperature and the light pump power until the mode-locked frequency returns back into the self-feedback adjustment range.

In one aspect, a device is disclosed that includes one or more input ports structured to receive a pumping light at a pumping wavelength and a signal light at a signal wavelength, and one or more output ports structured to output light including an amplified signal light at the signal wavelength and a second harmonic idler light. The device includes a nonlinear optical material to mix the pumping light and the signal light and to cause nonlinear conversion of the pumping light into the amplified signal light and generate an idler light at an idler wavelength. The nonlinear optical material is further structured to convert the idler light into the second harmonic idler light which eliminates the idler light at the one or more output ports and prevents back-conversion of the amplified signal light and idler light to the pumping wavelength.

A current control device supplies a current to a semiconductor laser in order to output laser light to the semiconductor laser, and includes a current commander and a supplier. The current commander outputs a command value corresponding to a current value by increasing the command value with a lapse of time until reaching a target command value corresponding to a current value for outputting the laser light with a predetermined strength. The supplier supplies a current with a size corresponding to the command value output by the current commander to the semiconductor laser.