C. D. Nabors

Efficient second harmonic generation of a diode-laser-pumped CW Nd:YAG laser using monolithic MgO:LiNbO/sub 3/ external resonant cavities

56% efficient external-cavity-resonant second-harmonic generation of a diode-laser pumped, CW single-axial-mode Nd:YAG laser is reported. A theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO/sub 3/. The best conversion efficiency was obtained with a 12.5-mm-long monolithic ring cavity doubler, which produced 29.7 mW of CW, single-axial mode 532-nm radiation from an input of 52.5 mW. >

Optical parametric oscillator frequency tuning and control

The frequency-tuning and -control properties of monolithic doubly resonant optical parametric oscillators are analyzed for stable single-mode pump radiation. Single-axial-mode operation is observed on the idler and the signal for both pulsed and continuous pumping. Projections are made for tuning-parameter tolerances that are required for maintenance of stable single-frequency oscillation. Continuous frequency tuning is possible through the simultaneous adjustment of two or three parameters; thus the synthesis of specific frequencies within the broad tuning range of the doubly resonant optical parametric oscillator is permitted.

Coherence properties of a doubly resonant monolithic optical parametric oscillator

We describe a doubly resonant optical parametric oscillator (DRO) pumped with the second harmonic of a narrow-linewidth Nd: YAG laser. The linewidth of the DRO signal was less than 13 kHz, the DRO was shown to generate a phase-locked subharmonic of the pump at degeneracy, and the signal and the idler were shown to be mutually coherent with the pump and to be phase anticorrelated with each other away from degeneracy. The signal–idler heterodyne linewidth was 500 Hz, and pump phase modulation was shown to transfer to the DRO phase at degeneracy.

Injection locking of a 13-W cw Nd:YAG ring laser

A lamp-pumped, 13-W cw Nd:YAG ring laser at 1.064 microm is injection locked using a 40-mW single-frequency diodelaser-pumped Nd:YAG laser as the master oscillator. The phase fidelity of the injected slave to the master is measured using an all-optical technique.

Efficient, single-axial-mode operation of a monolithic MgO:LiNbO(3) optical parametric oscillator.

A monolithic doubly resonant optical parametric oscillator (OPO) fabricated from MgO:LiNbO(3) was pumped by a cw, frequency-doubled, diode-laser-pumped Nd:YAG laser. The threshold for cw operation was 12 mW, and pump depletions of up to 78% were observed two times above threshold. The total OPO output power was 8.15 mW, with a conversion efficiency for the incident pump of 34% and combined conversion efficiency for the 1064-nm laser light of 14%. The OPO was temperature tuned from 1007 to 1129 nm, operated on a single-axial-mode pair over most of the range, and could be electric field tuned by as much as 38 nm near degeneracy.

Monolithic MgO:LiNbO(3) doubly resonant optical parametric oscillator pumped by a frequency-doubled diode-laser-pumped Nd:YAG laser.

We have demonstrated a monolithic MgO:LiNbO(3) doubly resonant optical parametric oscillator (OPO) using an allsolid- state pump. The pump laser was a single-axial-mode monolithic Nd:YAG nonplanar ring oscillator whose diode-laser pump was modulated at 325 kHz to produce relaxation oscillation spikes to higher peak powers at 1.06 microm that were frequency doubled in a resonant cavity to 532 nm. Pump depletions for the OPO of greater than 60% were observed when pumping six times above the calculated 40-mW threshold. The OPO output was temperature tuned from 1.01 to 1.13 microm, producing single-axial-mode output over much of the range. By changing the voltage applied across the OPO, the output wavelength was scanned as much as 11 nm in 310 V.

Second-harmonic generation of a continuous-wave diode-pumped Nd:YAG laser using an externally resonant cavity.

We report 13% second-harmonic conversion efficiency of a 15-mW, cw, diode-laser-pumped Nd:YAG oscillator. 2 mW of single-axial-mode 532-mm radiation was generated by externally resonant second-harmonic generation in a monolithic MgO:LiNbO(3) nonlinear crystal cavity. The measured finesse of 450 for the monolithic external cavity indicated that absorption and scatter losses in the doubler were less than 0.8%.

Efficient Second Harmonic Generation Of A Diode-Pumped Cw Nd:YAG Laser Using An Externally Resonant Cavity

Diode-pumped solid state lasers are efficient and compact sources of coherent IR radiation, but for many applications short wavelength visible sources are desired. Intracavity frequency doubling is a proven method of efficient conversion of these lasers to the visible, but generally results in deeply amplitude modulated output. An alternative approach is external cavity frequency doubling to provide stable single-axial-mode output at the second harmonic. We have used external cavity frequency doubling to generate 56% second harmonic conversion efficiency of a 53 mW, cw, diode-laser-pumped Nd:YAG oscillator. A monolithic cavity of MgO:LiNb03 resonant at the fundamental was used to generate the 30 mW of single axial mode 532 nm radiation.

Diode Pumped Solid-State Laser Oscillators for Spectroscopic Applications

Solid state laser development has been paced by the improvement of pumping sources. From the helical lamps used to pump the early Ruby lasers, to the linear arc and pulsed flashlamps used to pump Nd:YAG lasers, solid state laser pump sources have improved steadily in power and efficiency. The latest development is pumping solid state lasers with diode lasers and diode laser arrays. The development of high power, efficient, long lived diode lasers promises a revolution in solid state laser technology.

Monolithic Optical Parametric Oscillators for Quantum Optics

In recent years optical parametric oscillators1 have proven their worth as sources for quantum optics studies. As the archetypical source for squeezed states, parametric amplification has been used to produce squeezing in triply and doubly resonant OPOs, and in below- and above-threshold systems.2,3,4 OPOs are also undergoing a renaissance from a more conventional standpoint when used as widely tunable, narrow-band sources of light for spectroscopy and remote sensing applications.