Mid-IR broad area angled cavity diode lasers

Broad area diode lasers can effectively scale power, but suffer from degraded beam quality largely due to filamentation in a Fabry- Pérot cavity. Angled cavity waveguide has been proven to be able to suppress filamentation, but some high order modes still exist in the mid-IR angled cavity diode lasers we have fabricated recently. We discovered that removing certain regions that don’t contribute gain to the fundamental mode will shift mode competition toward the fundamental mode. Laser devices with such a modified angled cavity waveguide exhibit improved beam quality, and demonstrate a ~2 fold brightness enhancement to their Fabry-Pérot counterparts.