Abstract: A method and apparatus for controlling the form and timing of pulses emitted by a high-power solid-state laser, without the need for complex feedback circuits. The width and peak intensity of relaxation pulses emitted by the laser are controlled by use of an acousto-optic modulator (14) installed in the laser cavity, to lock the relaxation pulses to the frequency of radio-frequency (rf) control signals applied to the modulator. The number and average rate at which the pulses are emitted from the laser are independently controlled by varying the duty cycle of diodes (20) used to pump solid-state amplifiers (18) installed in the laser cavity. Short pump pulses can be selected to deliver only a few relaxation pulses from the laser, or longer pump pulses can be selected to deliver large numbers of relaxation pulses during each pump pulse.

Abstract: An intracavity doubled solid state Raman laser system for converting the frequency of a laser input beam emitted by a laser pumping system is described. A solid Raman medium is disposed within a resonator cavity to shift the frequency of the input beam to produce a Raman beam. The frequency of the Raman beam is tuned in the resonator cavity preferably using an etalon and a birefringent filter. The polarization of the Raman beam is selected using a polarizing element disposed in the resonator cavity. The Raman beam frequency is doubled using a non-linear doubling medium inside the resonator cavity. The Raman laser system is particularly suitable for producing yellow light.

Abstract: A solid-state laser architecture producing a beam of extremely high quality and brightness, including a master oscillator operating in conjunction with a zig-zag amplifier, an image relaying telescope and a phase conjugation cell. One embodiment of the laser architecture compensates for birefringence that is thermally induced in the amplifier, but injects linearly polarized light into the phase conjugation cell. Another embodiment injects circularly polarized light into the phase conjugation cell and includes optical components that eliminate birefringence effects arising in a first pass through the amplifier. Optional features permit the use of a frequency doubler assembly to provide output at twice optical frequencies, and an electro-optical switch or Faraday rotator to effect polarization angle rotation if the amplifier material can only be operated at one polarization.

Abstract: Apparatus, and a related method, for compensating for birefringence introduced in a birefringent medium, such as a solid-state amplifier. The invention includes the combination of a quarter-wave plate, a Faraday rotator and a mirror, which may be a phase conjugation cell. Light passing through the quarter-wave plate is substantially circularly polarized, which is advantageous if the mirror is a phase conjugation cell using stimulated Brillouin scattering (SBS). A second pass through the quarter-wave plate provides a linearly polarized beam of which the polarization angle is orthogonally related to that of the original beam, to facilitate out-coupling of energy from the apparatus. The Faraday rotator effects a total polarization angle rotation of 90.degree. in two passes and helps compensate for birefringence when the beam is passed through the birefringent medium again on the return pass.

Abstract: A solid-state laser architecture producing a beam of extremely high quality and brightness, including a master oscillator operating in conjunction with a zig-zag amplifier, an image relaying telescope and a phase conjugation cell. One embodiment of the laser architecture compensates for birefringence that is thermally induced in the amplifier, but injects linearly polarized light into the phase conjugation cell. Another embodiment injects circularly polarized light into the phase conjugation cell and includes optical components that eliminate birefringence effects arising in a first pass through the amplifier. Optional features permit the use of a frequency doubler assembly to provide output at twice optical frequencies, and an electro-optical switch or Faraday rotator to effect polarization angle rotation if the amplifier material can only be operated at one polarization.

Abstract: An ultracompact array of microlasers in which Q-switching is performed by intracavity electroabsorptive modulators, to provide an array of relatively high-power beams with good beam quality and other beam characteristics. The microlasers are optically pumped by light beams from an array of semiconductor diode lasers, each of which is individually controlled by a separate electrode. Light from the diode lasers is coupled directly into a slab of solid-state crystal material, such as Nd:YVO.sub.4 (neodymium:yttrium vanadate), in which laser action takes place. The solid state material in part defines an array of laser cavities and an array of individually controllable Q-switching elements is integrated into the cavities, permitting Q-switching of each of the array elements. The Q-switching elements are electroabsorptive modulators that permit extremely rapid switching of the microlaser elements and provide output pulses of relatively high peak powers.

Abstract: Apparatus and a related method for generating a second harmonic frequency optical output from a fundamental frequency input beam, without significant birefringence. The apparatus includes two Type II doubler crystals of equal length arranged with their corresponding axes parallel to each other, and a polarization rotator positioned between the doubler crystals, to rotate the polarization angle of a residual fundamental frequency component of an output beam from one of the crystals by 90.degree. or an odd multiple of 90.degree.. Random birefringence introduced into one of the doubler crystals is virtually canceled in the other, and the assembly of the two crystals and the polarization rotator may be angularly adjusted as needed for phase matching or tuning, without detracting from the birefringence compensation capability. The invention is also disclosed in the context of a phase conjugated master oscillator power amplifier (PC MOPA) system.

Abstract: A dual-wavelength laser emitter is provided for emitting a dual-wavelength laser beam. The laser emitter includes a first laser beam source for generating a first laser beam having a first frequency and a second laser beam source for generating a second laser beam having a second frequency. A beam splitter is included for combining portions of the first and second laser beams to form a dual-wavelength laser beam. The dual-wavelength laser beam is then amplified via an amplifier. A stimulated Brillouin scattering cell may be included to phase conjugate the dual-wavelength laser beam to improve the quality of the output beam. A frequency-doubling crystal may further be included for doubling the frequency of the dual-wavelength laser beam. The dual-wavelength laser emitter then emits a laser output beam as a function of the frequencies and amplitudes of the first and second laser beams.

Abstract: A highly-efficient solid-state blue laser that exploits a strong emission line provided by a solid-state laser medium of neodymium-doped scandium oxide (Nd:Sc.sub.2 O.sub.3) to produce a beam of coherent blue light at a wavelength matching the absorption line of cesium at 455.6 nm (0.4556 microns). The solid-state blue laser includes the laser medium of neodymium-doped scandium oxide, a semiconductor diode laser array for optically pumping the laser medium to produce a beam of coherent infrared radiation at a wavelength of approximately 1367 nm (1.367 microns), and optical means for tripling the frequency of the beam of coherent infrared radiation to produce a beam of coherent blue light at the wavelength of approximately 455.6 nm. The solid-state blue laser is simple, highly efficient and provides relatively high power outputs.

Abstract: A continuous wave HF R-branch chemical laser uses a linear array nozzle system having primary and secondary nozzles for exciting HF and a laser resonator having mirrors with reflectance to discriminate against P-branch lasing of the excited HF.