Abstract: A mode locked laser supplies a high repetition seed pulse train along a seed beam path to a pulse picker having at least one polarizer. A Faraday rotator in optical communication with the seed beam rotates the polarization of the seed beam by about 45°. A double pass acousto optical modulator (AOM) receives the seed beam propagating through the Faraday rotator and diffracts the seed beam into a first order first pass beam and a zero order first pass beam. A reflector returns the first pass first order beam into the acousto optical modulator for a second pass. The modulator diffract the beam into a zero order second pass beam and a first order second pass diffracted beam, the first order second pass beam propagating on the substantially same path as the incoming seed beam but in the opposite direction.

Abstract: A mode locked laser supplies a high repetition seed pulse train along a seed beam path to a pulse picker having at least one polarizer. A Faraday rotator in optical communication with the seed beam rotates the polarization of the seed beam by about 45°. A double pass acousto optical modulator (AOM) receives the seed beam propagating through the Faraday rotator and diffracts the seed beam into a first order first pass beam and a zero order first pass beam. A reflector returns the first pass first order beam into the acousto optical modulator for a second pass. The modulator diffract the beam into a zero order second pass beam and a first order second pass diffracted beam, the first order second pass beam propagating on the substantially same path as the incoming seed beam but in the opposite direction.

Abstract: A method and apparatus for spatially separating beams with different wavelengths is presented. The system includes: a light source (i.e. a laser with multiple harmonic output beams) with multiple wavelengths emitted along a single beam path or very nearly collinear beam paths, a path which connects the light source to a wavelength dependent beam separator, and a second path for blocking unwanted output wavelengths which connects the beam separation region to the laser output.

Abstract: According to the invention, a diode side pumped laser is provided. The laser has an optical cavity formed between a first and a second reflective surface. A Nd:YLF lasing medium is located within the cavity along its optical axis. The Nd:YLF lasing medium can desirably be a single Nd:YLF lasing rod which has a length of 90 mm or more. A plurality of diode bars are provided in optical communication with the Nd:YLF lasing medium preferably a lasing rod. The diode bars extend along substantially the pumpable length of the lasing rod and radially around the periphery of the lasing rod. The diode bars have radiation outlets in optical communication with the lasing rod for supplying electromagnetic radiation on pumping paths to the rod. The lasing rod receives an average linear power density from the diode bars of less than 50 watts/cm. The pumping paths traverse substantially the entire pumpable length of the lasing rod substantially perpendicular to the direction of propagation of energy in the laser cavity.

Abstract: A high pulse energy, side pumped laser is provided. The laser has an optical cavity formed between a first and a second reflective surface. A lasing medium is located within the cavity along its optical axis. A plurality of diode bars are provided in optical communication with the lasing medium preferably a lasing rod. The diode bars supply electromagnetic radiation to the lasing rod. The diode bars are configured about the lasing rod so that electromagnetic radiation from the diodes bars propagates through the lasing rod on a plurality of substantially nonintersecting paths. Since the lasing rod is side pumped, the substantially nonintersecting paths traverse the lasing rod substantially perpendicular to the direction of propagation of energy in the laser cavity.

Abstract: The invention relates to an improved harmonic laser which provides an externally generated harmonic beam. According to the invention, a third harmonic laser or higher harmonic laser is provided. The laser includes a first reflector and a second reflector for fundamental beam, forming a resonator cavity having an optical axis. The resonator includes a laser medium for producing a fundamental beam. The first reflector is highly reflective for fundamental beam. The second reflector is at least partially reflective for fundamental beam. A second harmonic generator is located within the resonator formed between the first high reflector and the second reflector for generating a second harmonic beam from the fundamental beam. Preferably the second harmonic generator is located so that the fundamental beam makes a first and second pass through the second harmonic generator. The resonator produces two output beams at least one of which is a harmonic beam.

Abstract: According to the invention, a laser and a method of operating a laser which can produce multiple pulses from a single laser head is provided. A lasing medium is pumped by pumping source such as laser diodes, lamp and such. A modulator located in the cavity is turned on to induce a loss in the laser cavity sufficient to prevent lasing. A first predetermined amount of energy is stored in the lasing medium while the modulator is turned on due to a creation of a population inversion in the lasing medium in excess of the lasing threshold. The modulator is then turned off for a period of time to allow the lasing medium to provide a first pulse. The modulator is then turned on before the population inversion in the laser medium is depleted completely so that a predetermined amount of energy remains stored in the lasing medium. After the first pulse, the modulator again induces a loss in the cavity sufficient to prevent lasing.

Abstract: Lasers are provided to deliver a wide variety of wavelengths at variable pulse energy. A laser cavity is formed between a first and second reflective surface. A lasing medium is located within cavity which lases at a preselected fundamental frequency. One or more nonlinear crystals are provided in optical communication with the lasing crystal to produce a secondary beam having a different frequency than the fundamental beam. A modulator is provided to control the pulse energy of the secondary beam. Desirably the secondary beam is a harmonic beam for example a second, third, fourth or fifth harmonic beam or a beam provided by an optical parametric oscillator.