A. Agnesi

Diode pumped Nd:YVO4 laser at 1.34 μm Q-switched and mode locked by a V3+:YAG saturable absorber

Abstract A diode-pumped Nd:YVO 4 laser passively Q-switched and mode locked by V 3+ :YAG generates as much as 505-mW average power at 1342 nm (30% of the cw output) in trains of sub-nanosecond pulses with energy as high as 0.7 μJ and repetition rates in the range 10–50 kHz.

Optical spectroscopy and diode-pumped laser performance of Nd/sup 3+/ in the CNGG crystal

We have exploited the broad absorption and emission bandwidth of the laser crystal Ca/sub 3/(NbGa)/sub 2-x/Ga/sub 3/O/sub 12/ doped with Nd/sup 3+/ to develop a tunable and mode locked diode-pumped 1.06 /spl mu/m laser. We also present the fluorescence and excitation spectra at different crystal temperatures from 10 to 298 K. The spontaneous transition probabilities, the branching ratios, and the radiative lifetime are calculated by means of the Judd-Ofelt theory and compared with the experimental results. The stimulated emission cross-sections of the most important transitions have been calculated and compared with laser results. Employing a 2-W laser diode as a continuous-wave pump source, we have been able to tune the emission wavelength in the range 1053-1074 nm. Active mode-locking yielding pulses of 9.6, 18, and 19.7 ps at the three main emission peaks of 1058.6, 1061.2, and 1065.3 nm, respectively. was also demonstrated.

High-power diode-pumped picosecond Nd 3+ :YVO 4 laser

A diode-pumped Nd(3+):YVO(4) laser passively mode locked by a nonlinear mirror based on second-harmonic generation has been developed. Pumping with a fiber-coupled 10-W diode array, we generated nearly diffraction limited, linearly polarized 11-ps pulses at 1064nm, with average power of 2.7 W at a 150-MHz repetition rate. Pulses as short as 7.9 ps were measured with reduced output power (1.35 W) by optimal focusing in the nonlinear crystal.

430-mW single-transverse mode diode-pumped Nd:YVO/sub 4/ laser at 671 nm

A diode-pumped Nd:YVO/sub 4/ laser operating at 1342 nm and intracavity doubled has been developed. Employing a type II noncritically phase-matched LiB/sub 3/O/sub 5/ (LBO) crystal, we generated 430 mW at 671 nm in single transverse mode. Operating at /spl ap/85% of the maximum output power we also selected a single axial mode.

Compact, 1.5 mJ, 450 MHz, CdSiP 2 picosecond optical parametric oscillator near 6.3 μm

We report a compact, efficient, high-energy, and high-repetition-rate mid-IR picosecond optical parametric oscillator (OPO) based on the new nonlinear material CdSiP(2) (CSP). The OPO is synchronously pumped by a master oscillator power amplifier system at 1064.1 nm, providing 1 μs long macropulses constituting 8.6 ps micropulses at 450 MHz, and it can be tuned over 486 nm across 6091-6577 nm, covering the technologically important wavelength range for surgical applications. Using a compact (∼30 cm) cavity and improved, high-quality nonlinear crystal, idler macropulse energy as high as 1.5 mJ has been obtained at 6275 nm at a photon conversion efficiency of 29.5%, with >1.2 mJ over more than 68% of the tuning range, for an input macropulse energy of 30 mJ. Both the signal and idler beams are recorded to have good beam quality with a Gaussian spatial profile, and the extracted signal pulses are measured to have durations of 10.6 ps. Further, from the experimentally measured transmission data at 1064 nm, we have estimated the two-photon absorption coefficient of CSP to be β=2.4 cm/GW, with a corresponding energy bandgap, E(g)=2.08 eV.

1.5 Watt passively Q-switched diode-pumped cw Nd:YAG laser

Abstract A medium-power all-solid-state diode-pumped cw Nd:YAG laser, passively Q -switched employing Cr 4+ :YAG as saturable absorber, has been developed. Optimum coupling operation at the 1064 nm working wavelength resulted in 100 μJ, 36 ns, nearly diffraction limited pulses at 15 kHz repetition frequency, with 1.5 W average power output. We discuss the characterisation of the passive Q -switching elements and the laser operation.

Efficient wavelength conversion with high-power passively Q-switched diode-pumped neodymium lasers

Powerful CW diode-pumped Nd:YAG and Nd:YVO4 lasers Q-switched by Cr:YAG saturable absorbers demonstrate efficient (30%-60%) harmonic and parametric conversion, generating hundreds of milliwatts from ultraviolet to mid-infrared.

High-repetition-rate Q-switched diode-pumped Nd:YAG laser at 1.444 μm

A diode-pumped Q-switched Nd:YAG laser that operates at the eye-safe 1444 nm wavelength has been developed. When pumped by a 10-W fiber-coupled array at 808 nm, it generated 1 W in cw operation and 560 mW at 20-kHz repetition rate with active Q-switching. Design issues such as thermal lensing characterization and beam quality are discussed.

DESIGN AND CHARACTERIZATION OF A DIODE-PUMPED, SINGLE LONGITUDINAL AND TRANSVERSE MODE, INTRACAVITY-DOUBLED CW ND:YAG LASER

We report on the experimental results of a diode-pumped, intracavity-doubled cw Nd:YAG laser, pumped by a 10-W fiber-coupled semiconductor laser at 808 nm and emitting as much as 600 mW in a stable single longitudinal mode and TEM(00) spatial mode. We discuss the main issues of the resonator design and the optimization of the intracavity second harmonic conversion by interpreting our results using simple models. Improvements for the current project are also discussed.

Numerical evaluation of the Hankel transform : remarks

The method originally proposed by Siegman [ Opt. Lett.1, 13 ( 1977)] for evaluating numerically the Hankel transform by fast-Fourier-transform techniques is reconsidered. A novel analytical form is found that permits a numerical computation of the Hankel transform with accuracy comparable with that of Siegman’s approach without lower-end corrections; but for simplicity and numerical efficiency the original approach remains unsurpassed.