Abstract

Recently, there has been great interest in polarization-insensitive semiconductor optical amplifiers (SOAs) for both 1.3 μm¹ and 1.55 μm.² The polarization insensitivity is achieved by alternating compressive and tensile-strained quantum wells in the active region. Because of polarization selection rules, the compressive wells provide gain only for light polarized along the active layers (TE), while the tensile wells provide gain mainly to light polarized perpendicular to the active layers (TM). These structures are therefore ideal for pump-probe studies, since varying the relative polarization between the pump and probe pulses will isolate processes occurring in different wells. In particular, when the pump is TM polarized and the probe TE polarized, interband transitions will be induced primarily in the tensile wells by the pump, and the probe will be sensitive mainly to the compressive wells. This configuration may permit us to learn about interwell transport.

© 1995 Optical Society of America