Search

Examines the experimental determination of the thermo-optical coefficient and the effective stimulated emission cross-section at 1064 nm for a neodymium-doped gadolinium vanadate crystal. Thermal lensing effect in the monolithic laser; Overlap integral values; Laser properties of the gadolinium vanadate.

Simultaneous Q-switching and mode-locking in a laser-diode end-pumped intracavity frequency doubled Nd:YVO4/KTP green laser using Cr4+:YAG saturable absorber is experimentally demonstrated. The influence of the initial transmission (T0) of the Cr4+:YAG crystal on the Q-switched mode-locked green pulses as well as on the average green power is characterized by using Cr4+:YAG crystal with various T0. The effect of T0 on the pulse build-up time in intracavity second harmonic configuration is theoretically investigated. It was found that the depth of modulation for the mode-locked pulses is greatly improved at the second harmonic wavelength as compared to that for the fundamental wavelength. The average pulse duration of the individual mode-locked pulse for the second harmonic beam measured to be less than 500 ps with a repetition rate of 400 MHz. [Copyright &y& Elsevier]

We report intracavity second harmonic (at 532 nm) generation in a passively Q-switched mode-locked Nd:YVO4 laser. The width of a typical Q-switched envelope of the mode-locked pulses for the green laser was around 65 ± 5 ns and the repetition rate for the mode-locked pulses was 400 MHz. The intracavity frequency doubling significantly improves the depth of modulation of the mode-locked pulses. The peak power of a single mode-locked green pulse near the center of the Q-switched envelope was estimated to be more than 2 kW and the average green power was 6 times higher than the CW green power at an incident diode pump power of 6 W. [Copyright &y& Elsevier]

In this paper we demonstrated and analyzed a high-power cw Nd:CNGG laser end-pumped by a fiber-coupled diode laser array in a convex–concave-type cavity. TEM00 mode output power of 1.63 W was obtained with 27% optical-to-optical conversion efficiency and slope efficiency of 44.5%. Thermal lensing and its variation with the incident pump power for this crystal have been measured. The coefficient for pump power induced diffraction losses of Nd:CNGG crystal have also been estimated for this laser configuration. [Copyright &y& Elsevier]

A practical method is described and used for determination of the effective stimulated emission cross-section (σe) in an operating diode pumped Nd:YVO4 micro-laser at 1064 nm with various doping concentrations. In this method a micro-laser is formed by keeping a small piece of the sample in a plane–plane resonator under semi-monolithic configuration and a fiber coupled diode laser (808 nm) was used for pumping. The pump power induced thermal lensing effect was used to make the cavity stable. In thermally stabilized solid-state lasers the cavity parameters change dynamically with the pump power and hence the overlap integrals become a function of the absorbed pump power. In our method the overlap integrals were estimated by measuring the thermal lens focal length at the threshold. The value of σe of Nd:YVO4 crystal with different doping concentrations obtained by this method were in well agreement with the reported values. [Copyright &y& Elsevier]

A simple approach is described and used for on-line measurement of the fractional heat-load parameter ξ in an operating diode-pumped Nd:YVO4 laser at 1.06 μm wavelength for different doping concentrations. The method is based on the fact that if the thermo-optical properties of the sample are known then the ξ-parameter can be estimated from the measured effective focal length induced by the pump beam and any other lensing effect due to mechanical mounting of the sample for a given pumping configuration. The value of the fractional heat-load parameter estimated by our technique was in excellent agreement with the earlier reported values. [Copyright &y& Elsevier]