TE/TM mode switching of GaAsP strained quantum-well laser diodes

摘要

Abstract: per demonstrates TE/TM mode switching in GaAsP/AlGaAs tensilely strained quantum-well laser diodes (LDs) with multiple electrodes. The quantum-well layers are grown by low-pressure metal organic vapor phase epitaxy. For a 250-$mu@m-long cavity, the threshold current density of this LD wafer at room temperature is about 1.6 kA/cm$+2$/. With a long cavity these LDs operate in the TM mode, but the TE mode dominates when the cavity is shorter than 200 $mu@m. TE/TM mode switching is obtained in a two-electrode laser with electrodes 150 $mu@m and 80 $mu@m long. When current is injected into both electrodes this LD oscillates at 790 nm in the TM mode and with a threshold current of 40 mA. When current is injected only into the longer electrode, however, it oscillates at 800 nm in the TE mode and absorption at the region under the shorter electrode increases the threshold current to 80 mA. For both kinds of oscillation the suppression ratio is greater than 10 dB. This LD operates in the fundamental mode over an injection-current range of several milliwatts.!6