1 kHz 3.3 µm Nd:YAG KTiOAsO4 optical parametric oscillator system for laser ultrasound excitation of carbon-fiber-reinforced plastics.

ABSTRACT

We present a new laser prototype for laser ultrasonics excitation. The fundamental wavelength of a Q-switched NdYAG 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.