Polarization-independent Δ-strained semiconductor opticalamplifiers: a tight-binding study

摘要

We present a tight-binding analysis of the polarization dependencenof GaAs Δ-strained semiconductors optical amplifiers. Our approachnallows us to account for band nonparabolicity, valence band mixing, asnwell as thin layer perturbations, overcoming the natural limitations ofnstandard techniques based on the envelope function formalism. We explainnhow thin strained GaAs layers embedded in a lattice-matchednInGaAsP-InGaAs quantum well can he used to achievenpolarization-insensitive optical amplification. The theory is alsonapplied to other structures providing optical amplification, showing hownthe concept of “virtual barriers” can lead to highnpolarization insensitivity