A room temperature opticaly pumped solid state laser operating in the 0.8 to 0.9 micron region with inherently low beam divergence enchances covert laser systems because of compatability with high quantum efficiency low noise photocathodes.
This application is a division of my copending application entitled "Laser System" Ser. No. 249,172, filed May, 1, 1972 and now U.S. Pat. No. 3,833,805.
A room temperature, optically pumped, solid state laser operating at 0.75 micrometers including a Ho.sup.3+ :LiYF.sub.4 crystal provides an excellent source for optical target location systems and other applications which require a source of high peak power in the spectral region just beyond the visible - the "Deep Red".
A room-temperature, laser-pumped, Q-switched, thulium-doped, solid state laser for producing pulses of laser emission at substantially 2 microns is disclosed. In a preferred embodiment, the laser comprises: a laser cavity defined by first and second reflective elements opposing each other on a common axis to form a reflective path therebetween; a laser crystal disposed in the laser cavity, the laser crystal having a host material doped with an amount of thulium activator ions sufficient to produce a laser emission at substantially 2 microns from the .sup.3 F.sub.4 to .sup.3 H.sub.6 laser transition in the thulium activator ions when the laser crystal is enabled and is pumped by a CW pump beam at a preselected wavelength; a pump laser for pumping the laser crystal with the CW pump beam at the preselected wavelength; and a Q-switch disposed in the laser cavity between the laser crystal and the second reflective element for periodically enabling the laser crystal to produce a pulsed laesr emission at substantially 2 microns when the laser crystal is also pumped by the CW pump beam.
A high efficiency, high power blue-green laser capable of providing short lses useful for underwater communication and detection systems. To provide the desired blue-green lasing, a solid state laser is pumped by a matched high-efficiency laser having a relatively long duration output pulses. Q-switching of the solid state laser is used to shorten the duration and increase the peak power of the pulses. Material found especially useful for practice of the invention are Holmium.sup.+3 and Praseodymium.sup.+3 as the solid state laser and a dye laser pumped by a mercury capillary lamp as the pumping laser.
A tunable laser system emitting coherent radiation selectively variable over the range of wavelengths from about 1650 A to about 3300 A utilizes a crystal, composed of a fluoride of at least a Column IIIb metal doped with at least one trivalent ion of a lanthanide series element, and pumped with high average power pulses. The crystal is emplaced in an optical cavity having means, such as a diffraction grating, etalon, or optically-tunable prism, to vary the coherent emission wavelength.
