High-Power 1770 nm Emission of a Membrane External-Cavity Surface-Emitting Laser

An InGaAlAs/InP membrane external-cavity surface-emitting laser (MECSEL) operating at 1770 nm is reported for the first time. A record high power of 7.7 W is registered at -20°C. This is the record high emission power registered for any surface emitting InGaAlAs-based semiconductor laser at a wavelength longer than 1480 nm. A power value of 3.5 W is measured at 20 °C. The lasing is observed up to 60 °C. The high-power emission is achieved due to lateral and longitudinal power scaling realized by enlarging the pump spot diameter to $400~\mu \text{m}$ and the double-side pumping (DSP) of a single chip of extended thickness. We analyze the thermal properties and evaluate the temperature inside the laser membrane. We present the characteristic temperature (T0) as a function of temperature. The T0 is measured to be 70 K at -20°C and 26 K at 55 °C. Our data support the explanation that the increase in the maximum power of the DSP MECSEL originates from an improvement in the thermal properties rather than from more uniform carrier injection into the quantum wells.