Materials for wide-band amplification

The material gain of InGaAsP/InGaAsP quantum-well active layers is calculated, including tetragonal strain and confinement effects. For compressively strained structures, the calculated optical bandwidth reaches 150 nm. For structures under tensile strain, the optical bandwidth reaches 110 nm with a polarization sensitivity which is lower than 1 dB between TE and TM emissions over the -3dB optical bandwidth. Further enlargement of the optical bandwidth is expected by reducing the quantum well width.