B.D. Sinclair

Blue microchip laser fabricated from Nd:YAG and KNbO3

A Nd:YAG/KNbO(3) composite-material microchip laser has generated blue radiation at 473 nm with output powers of 1 mW when diode laser pumped and 9 mW when Ti:sapphire laser pumped. The fundamental radiation generated by the quasi-three-level (4)F(3/2)-(4)I(9/2) transition in Nd:YAG at 946 nm was frequency doubled in KNbO(3) angle cut to be type I critically phase matched at 45 degrees C. Despite the normally isotropic nature of Nd:YAG, the fundamental is emitted linearly polarized and orthogonal to the linearly polarized blue radiation.

A comparative study of diode pumped microchip laser materials: Nd-doped YVO4, YOS, SFAP and SVAP

Abstract The lasing performance of the Nd-doped microchip laser host materials YVO4, YOS, SFAP and SVAP operating on the 1 μm transition in Nd is examined. With 0·5 W and 2 W laser diode array pump sources Nd:YVO4 remains the material of choice for this transition while both Nd:SFAP and Nd:YOS show promise, although higher doping concentrations are required. Pump-induced damage made Nd:SVAP unsuitable as a microchip laser material.

Polarization effects, birefringent filtering, and single-frequency operation in lasers containing a birefringent gain crystal

The effect of having a birefringent gain crystal is studied in the context of two laser systems: an intracavity frequency-doubled microchip laser and a compact single-frequency laser utilizing a birefringent filter. A model based on Jones calculus is proposed to predict the polarization and wavelength structure of the longitudinal modes and is found to be consistent with experimental measurements. The optimization of these systems is discussed, and the importance of the birefringences in the cavity and cavity length is indicated.

Self-Q-switched Nd:YVO4 microchip lasers.

We have observed giant pulses from cw pumped, monolithic Nd:YVO(4) microchip lasers, several hundred times the cw level, with pulse lengths less than 2 ns, which cannot be accounted for by conventional gain switching. These pulses occur as the second longitudinal mode starts to oscillate and can be described by the inclusion of gain-related effects in the formation of a stable cavity.

All-solid-state optical parametric oscillator for the visible.

An all-solid-state optical parametric oscillator (OPO) with signal and idler waves tunable over the ranges 481-457 and 1355-1590 nm, respectively, has been developed. Radiation at 1064 nm from a diode-laser-pumped Nd:AG laser (delivering 10-mJ Q-switched pulses of 18-ns duration at rates of 10-100 Hz) is frequency tripled at efficiencies near 30% and then used to pump the lithium triborate OPO, thus an all-solid-state configuration is realized. Oscillation thresholds (0.4 mJ), pump depletions (50%), external efficiencies (27%), and temperature-tuning rates (signal -0.11 nm/ degrees C, idler +0.87 nm/ degrees C) for the OPO are reported.

A visible extended cavity diode laser for the undergraduate laboratory

We demonstrate how to construct a simple single-frequency extended cavity diode laser (ECDL) for the undergraduate laboratory using mainly standard opto-mechanical components. This ECDL is operated with both 635 and 670 nm laser diodes. We present three experiments that can be performed using this ECDL, namely spectroscopic studies of iodine, second harmonic generation, and an optical heterodyne experiment using the ECDL with a helium–neon laser.

Single-frequency, end-pumped Nd:YLF laser excited by a 12-mJ diode-laser array

We describe the operation of a diode-laser-pumped, end-pumped Nd:YLF laser that utilizes a 12-mJ, 60-W, quasicw diode-laser bar. Multilongitudinal-mode, TEM(00) pulse energies of greater than 2 mJ have been observed, with corresponding Q-switched peak output powers in excess of 118 kW. The incorporation of a prelase Q-switching technique has seen single-longitudinal-mode peak powers in excess of 90 kW continuing to be achieved. The low-threshold operation at 1.539 microm of a singly resonant KTP optical parametric oscillator pumped by this source is also reported.

Experimental Evaluation of a Fibre Raman Oscillator Having Fibre Grating Reflectors

We report on the construction and characterization of a novel fibre Raman oscillator which used fibre grating reflectors rather than discrete mirrors to form the Raman resonator. This was synchrono...

Laser-diode-pumped, electro-optically tunable Nd:MgO:LiNbO 3 microchip laser

We have demonstrated continuous-wave operation of a microchip laser fabricated from Nd:MgO:LiNbO3 and pumped by a laser diode. Incident pump power thresholds of 32 mW with slope efficiencies of 6.5% were observed. The microchip laser operated in the lowest-order transverse mode at all output powers up to and including the maximum output power of 13 mW. Application of an electric field transverse to the cavity axis permitted tuning of the oscillating cavity modes to be obtained at a rate of 8.9 MHz V−1 mm.

Compact, actively Q-switched optical parametric oscillator

An ultracompact, actively Q -switched optical parametric oscillator (OPO) has been realized that is only 30 mm in length, based on a semimonolithic microchip laser, a quadrupole deflector, and a monolithic periodically poled lithium niobate crystal. The OPO threshold was 550 mW when Nd:YAG was used as the gain material and 590 mW for Nd:Y VO(4), giving signal pulses of as much as 8.7 muJ in energy with Nd:YAG at 1 kHz and 5.9-muJ pulses with Nd:Y VO(4) at 5 kHz, for 1.2- and 2-W laser diode pumping, respectively. The output was single frequency and could be tuned over the range 1540-3440 nm.