Diode-pumped passively Q-switched high-brightness microchip lasers

We have demonstrated the diode end-pumped high-brightness Nd
³⁺
:YAG microchip lasers, passively Q-switched by Cr
⁴⁺
:YAG as a saturable absorber (SA). In order to optimize the output characteristic of the laser, we have investigated the transmission of Cr
⁴⁺
:YAG, and acquired the dependence of the pulse energy density on the initial transmission with the final transmission that was provided from the measurement. As a result, its maximum output pulse energy was 0.95 mJ with the pulse width of 480 ps and the peak power was 1.7 MW and a beam quality was M
²
= 1.05 with 100 Hz repetition frequency.