High-power DBR-free VECSELs emitting at 1178 nm for sodium guide star applications

DBR-free VECSELs overcome long-standing limitations in standard devices and offer improved heat management, reduced growth complexity, larger material choice, and broader gain tunability. We present the latest advances in DBR-free VECSELs emitting at 1178 nm targeting sodium guide star applications. We compare barrier-pumping and in-well pumping schemes employing 808 nm and 1070 nm pump lasers, respectively. A maximum output power of >20 W is attained with the barrier-pumping configuration, while a ~52 % slope efficiency with single pass is obtained with the in-well pumping scheme. Linewidth narrowing of < 0.25 nm and frequency conversion to 589 nm is also presented.