We report on the room-temperature continuous-wave operation of vertica
l-cavity lasers operating at 154 mu m. The devices me a 7 strain-compe
nsated quantum-well active layer sandwiched between two Al(Ga)As-GaAs
quarter-wave mirrors joined by wafer fusion. Five device sizes between
8 and 20 mu m were found to operate continuously at room temperature
(23 degrees C). The lowest room-temperature continuous-wave threshold
current of 2.3 mA was measured on an 8-mu m diameter device, while the
highest continuous-wave operating temperature of 33 degrees C was mea
sured on a 12-mu m device.