Investigation of the temporal behavior of the self-Q-switched Ho:GdVO4 laser pumped by a Tm-doped fiber laser

Abstract

We investigate the temporal behavior of a self-Q-switched Ho:GdVO4 laser at 2074 nm by analyzing the variation of reabsorption region with the incident pump power. The different temporal behaviors of self-Q-switched Ho:GdVO4 laser are observed by changing the incident pump power. When the incident pump power is below 11.7 W, the self-Q-switching pulse train are stable and fully modulated. However, once the incident pump power exceeds 11.7 W, the modulation depth of output laser pulse train drops sharply with the increase of incident pump power until the pulsing phenomenon disappears. Under considering the ground state reabsorption effect, the temporal behavior of self-Q-switched Ho:GdVO4 laser is discussed by calculating the variation of reabsorption region with the incident pump power, and the theoretical analysis can explain the experimental results very well. The maximum average output power of self-Q-switched Ho:GdVO4 laser reaches 1.07 W at the incident pump power of 11.7 W, with a pulse width of 1.808 µs and a pulse repetition frequency of 56.53 kHz. To the best of our knowledge, this is the first Ho doped self-Q-switched solid state laser.