RESUMEN
We present a new laser prototype for laser ultrasonics excitation. The fundamental wavelength of a Q-switched Nd:YAG laser with a repetition rate of 1 kHz is converted to 3.3 µm with a KTiOAsO4 optical parametric oscillator. The achieved pulse energy at 3.3 µm is 1.7 mJ, and the pulse duration at the fundamental wavelength of 1.06 µm has been measured to be 21 ns. The ultrasonic excitation efficiency is about 3.5 times better compared to the application of state-of-the-art CO2 lasers.
RESUMEN
A miniaturized, passively Q-switched Nd:YAG laser oscillator-power amplifier is reported, which is axially pumped by a compact, fiber-coupled, high-power, quasi-cw diode laser module. The pumping intensity of the oscillator crystal can be adjusted independently of the pumping intensity of the amplifier. This ensures that the oscillator pulse enters the amplifier when its maximum population density is reached. Furthermore, pulse bursts can be generated with a definite, adjustable number of single pulses. Maximum pulse energies of 8.4 and 22 mJ were achieved for a single pulse and for a pulse burst, respectively, at a pumping power of 470 W. The pulse widths were 2 ns, whereas the beam quality corresponded to M2<1.5. The laser is appropriate for scaling the power to the 10 MW range. Operation by using a 100 m pumping fiber was demonstrated.
RESUMEN
We report on a compact, tunable ultraviolet laser system that consists of an optical parametric oscillator (OPO) and a longitudinally diode-pumped Nd:YAG master oscillator-power amplifier (MOPA). The pump energy for the whole laser system is supplied via a single delivery fiber. Nanosecond pulses are produced by an oscillator that is passively Q-switched by a Cr(4+):YAG crystal. The OPO is pumped by the second harmonic of the Nd:YAG MOPA. Continuously tunable radiation is generated by an intracavity sum-frequency mixing process within the OPO in the range of 245-260 nm with high beam quality. Maximum pulse energies of 1.2 mJ were achieved, which correspond to an optical efficiency of 3.75%, relating to the pulse energy of the MOPA at 1064 nm.