High Energy Passively Q-Switched Laser on a CMOS Platform

High energy Q-switched lasers are highly desirable for various applications ranging from sensing, micro machining and medical applications especially in the long wavelength window
$(> 1.8\upmu \mathrm{m})$
. Such lasers are usually based on large benchtop solid-state or fibre systems. Integrated rare-earth doped medium [1]–[5] has been an excellent candidate for high energy pulse generation with high beam quality. In this work, we show CMOS compatible Q-switched laser around 1.9
$\mu \mathrm{m}$
with an on-chip output energy over 150 nJ in a footprint <10 mm
²
. The pulse energy demonstrated in this work is comparable to passively Q-switched fibre lasers [6].