POLARIZATION-INSENSITIVE OPTICAL AMPLIFIER WITH TENSILE-STRAINED-BARRIER MQW STRUCTURE

A new approach to achieving a polarization-insensitive semiconductor o ptical amplifier is presented. The active layer consists of a tensile- strained-barrier MQW structure that enhances TM mode gain. Polarizatio n sensitivity below 0.5 dB is realized at a wavelength of 1.56 mum. A signal gain of 27.5 dB is obtained along with a saturation output powe r of 14 dBm. Deriving the refractive indices of well and barrier layer s from both experiment and theory, we succeed in separation of the eff ect of the confinement factor and the gain coefficient. It is determin ed that TM mode gain enhancement in this structure is primarily due to the increase in the confinement factor.