Stability of Q-switched 2 µm lasers

Q-switched lasers operating at wavelengths around 2 µm have many applications including materials processing and LIDAR. However, the low gain of the quasi-three-level gain media available at 2 µm can lead to problems with pulse-to-pulse fluctuations in their output, known as jitter. Here we present a methodology for characterising the level of jitter in a Q-switched laser and apply it to a Tm:YAP system. We also look at the causes of jitter and evaluate some methods of reducing it. The methodology developed here will aid in the development and characterisation of Q-switched lasers at any wavelength.