Abstract: A new class of lasers is provided that can be pumped by conventional high-power, multi-mode, broadband 1-D and 2-D laser diode arrays with spectral widths greater than 0.01 nm, where the pumped laser gain medium comprises an atomic vapor of one the alkali elements (Li, Na, K, Rb or Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne or Xe) and selected molecular gases. The alkali atom gain medium is pumped at a wavelength matching the wavelength of the 2S1/2–2P3/2 electric-dipole-allowed transition (the D2 transition). After kinetic relaxation of pump excitation to the excited 2P1/2 electronic level, laser emission takes place on the 2P1/2–2S1/2 transition (the D1 transition).

Abstract: Compact, high-power, near-diffraction-limited sources of radiation in the near infrared spectral region are provided by a new class of power amplifiers that can be pumped by conventional high-power, multimode, relatively-broadband 1-D and 2-D laser diode arrays, where the pumped amplifier gain medium is an atomic vapor of one of the alkali elements (Li, Na, K, Rb, Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne, or Xe) and selected molecular gases. Given the central role of the alkali atomic vapor as the entity providing amplifier gain, this new type of amplifier is herein designated as the diode-pumped alkali amplifier (DPAA).

Abstract: Optically-pumped mid-infrared vibrational-rotational transition gas lasers and amplifiers with improved efficiency and practicality. Inventive laser and amplifier devices include: laser active media comprising a mixture of alkali vapor, selected hetero-nuclear molecular gas, and one or more buffer gases; conventional semiconductor laser diode pump sources with nanometer scale spectral bandwidths; and preferential laser emission in ro-vibrational transitions among relatively low-lying vibrational levels.

Abstract: Compact, high-power, near-diffraction-limited sources of radiation in the near infrared spectral region are provided by a new class of power amplifiers that can be pumped by conventional high-power, multimode, relatively-broadband 1-D and 2-D laser diode arrays, where the pumped amplifier gain medium is an atomic vapor of one of the alkali elements (Li, Na, K, Rb, Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne, or Xe) and selected molecular gases. Given the central role of the alkali atomic vapor as the entity providing amplifier gain, this new type of amplifier is herein designated as the diode-pumped alkali amplifier (DPAA).

Abstract: A new class of lasers is provided that can be pumped by conventional high-power, multi-mode, broadband 1-D and 2-D laser diode arrays with spectral widths greater than 0.01 nm, where the pumped laser gain medium comprises an atomic vapor of one the alkali elements (Li, Na, K, Rb or Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne or Xe) and selected molecular gases. The alkali atom gain medium is pumped at a wavelength matching the wavelength of the 2S1/2-2P3/2 electric-dipole-allowed transition (the D2 transition). After kinetic relaxation of pump excitation to the excited 2P1/2 electronic level, laser emission takes place on the 2P1/2-2S1/2 transition (the D1 transition).

Abstract: In the basic Diode-Pumped Alkali Laser (DPAL) device, excitation to the n 2P3/2 electronic level by a single diode laser pump source leads to a population inversion between the first excited electronic 2P1/2 level and the ground 2S1/2 level, permitting the construction of efficient, high-power, compact DPAL laser oscillators in the near infrared spectral region. The present invention extends the single-step excitation DPAL to a two-step excitation, or up-conversion DPAL to produce efficient, powerful laser operation in the visible blue and near UV spectral regions (viz., in the range 460-323 nm). The present invention describes an apparatus and method that efficiently sums the energy of two, near-infrared diode pump photons in alkali vapor atoms, followed by stimulated emission to their electronic ground levels.

Abstract: A new class of lasers is provided that can be pumped by conventional high-power, multi-mode, broadband 1-D and 2-D laser diode arrays, where the pumped laser gain medium comprises an atomic vapor of one the alkali elements (Li, Na, K, Rb or Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne or Xe) and selected molecular gases. The alkali atom gain medium is pumped at a wavelength matching the wavelength of the 2S1/2-2P3/2 electric-dipole-allowed transition (the D2 transition). After kinetic relaxation of pump excitation to the excited 2P1/2 electronic level, laser emission takes place on the 2P1/2-2S1/2 transition (the D1 transition).

Abstract: A new class of lasers is provided that can be pumped by conventional high-power, multi-mode, broadband 1-D and 2-D laser diode arrays, where the pumped laser gain medium comprises an atomic vapor of one the alkali elements (Li, Na, K, Rb or Cs), buffered with a mixture of rare-gas (He, Ar, Kr, Ne or Xe) and selected molecular gases. The alkali atom gain medium is pumped at a wavelength matching the wavelength of the 2S1/2−2P3/2 electric-dipole-allowed transition (the D2 transition). After kinetic relaxation of pump excitation to the excited 2P1/2 electronic level, laser emission takes place on the 2P1/2−2S1/2 transition (the D1 transition).

Abstract: In the basic Diode-Pumped Alkali Laser (DPAL) device, excitation to the n 2P3/2 electronic level by a single diode laser pump source leads to a population inversion between the first excited electronic 2P1/2 level and the ground 2S1/2 level, permitting the construction of efficient, high-power, compact DPAL laser oscillators in the near infrared spectral region. The present invention extends the single-step excitation DPAL to a two-step excitation, or up-conversion DPAL to produce efficient, powerful laser operation in the visible blue and near UV spectral regions (viz., in the range 460-323 nm). The present invention describes an apparatus and method that efficiently sums the energy of two, near-infrared diode pump photons in alkali vapor atoms, followed by stimulated emission to their electronic ground levels.

Abstract: Using a thin disk laser gain element with an undoped cap layer enables the scaling of lasers to extremely high average output power values. Ordinarily, the power scaling of such thin disk lasers is limited by the deleterious effects of amplified spontaneous emission. By using an undoped cap layer diffusion bonded to the thin disk, the onset of amplified spontaneous emission does not occur as readily as if no cap layer is used, and much larger transverse thin disks can be effectively used as laser gain elements. This invention can be used as a high average power laser for material processing applications as well as for weapon and air defense applications.

Abstract: The invention provides an efficient, compact means of generating blue laser light at a wavelength near ˜493+/−3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near ˜986+/−6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the ˜490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from ˜980 to ˜992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm).

Abstract: In a master oscillator-power amplifier (MOPA) hybrid laser system, the master oscillator (MO) utilizes a Nd3+-doped gain medium and the power amplifier (PA) utilizes a diode-pumped Yb3+-doped material. The use of two different laser gain media in the hybrid MOPA system provides advantages that are otherwise not available. The Nd-doped gain medium preferably serves as the MO because such gain media offer the lowest threshold of operation and have already been engineered as practical systems. The Yb-doped gain medium preferably serves in the diode-pumped PA to store pump energy effectively and efficiently by virtue of the long emission lifetime, thereby reducing diode pump costs. One crucial constraint on the MO and PA gain media is that the Nd and Yb lasers must operate at nearly the same wavelength. The 1.047 &mgr;m Nd:YLF/Yb:S-FAP [Nd:LiYF4/Yb:Sr5(PO4)3F] hybrid MOPA system is a preferred embodiment of the hybrid Nd/Yb MOPA.

Abstract: The invention comprises a RE-doped MA.sub.2 X.sub.4 crystalline gain medium, where M includes a divalent ion such as Mg, Ca, Sr, Ba, Pb, Eu, or Yb; A is selected from trivalent ions including Al, Ga, and In; X is one of the chalcogenide ions S, Se, and Te; and RE represents the trivalent rare earth ions. The MA.sub.2 X.sub.4 gain medium can be employed in a laser oscillator or a laser amplifier. Possible pump sources include diode lasers, as well as other laser pump sources. The laser wavelengths generated are greater than 3 microns, as becomes possible because of the low phonon frequency of this host medium. The invention may be used to seed optical devices such as optical parametric oscillators and other lasers.

Abstract: Dysprosium-doped metal chloride materials offer laser properties advantageous for use as optical amplifiers in the 1.3 .mu.m telecommunications fiber optic network. The upper laser level is characterized by a millisecond lifetime, the host material possesses a moderately low refractive index, and the gain peak occurs near 1.31 .mu.m. Related halide materials, including bromides and iodides, are also useful. The Dy.sup.3+ -doped metal chlorides can be pumped with laser diodes and yield 1.3 .mu.m signal gain levels significantly beyond those currently available.

Abstract: A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr.sup.2+ -doped ZnS and ZnSe generate laser action near 2.3 .mu.m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d.sup.4 and d.sup.6 electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers.

Abstract: High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes.

Abstract: Ce.sup.3+ -doped LiSrAlF.sub.6 crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF.sub.6 with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF.sub.6 type of chemical formula, e.g. Ce-doped LiCaAlF.sub.6 and LiSrGaF.sub.6, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation.

Abstract: Yb.sup.3+ and Nd.sup.3+ doped Sr.sub.5 (VO.sub.4).sub.3 F crystals serve as useful infrared laser media that exhibit low thresholds of oscillation and high slope efficiencies, and can be grown with high optical quality. These laser media possess unusually high absorption and emission cross sections, which provide the crystals with the ability to generate greater gain for a given amount of pump power. Many related crystals such as Sr.sub.5 (VO.sub.4).sub.3 F crystals doped with other rare earths, transition metals, or actinides, as well as the many structural analogs of Sr.sub.5 (VO.sub.4).sub.3 F, where the Sr.sup.2+ and F.sup.- ions are replaced by related chemical species, have similar properties.

Abstract: An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises Ytterbium doped apatite (Yb:Ca.sub.5 (PO.sub.4).sub.3 F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode.

Abstract: A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).