Polarization insensitive 1.55-μm optical amplifier with GaAs delta-strained Ga/sub 0.47/In/sub 0.53/As quantum wells

We report a novel, polarization insensitive, 1.55-μm semiconductor optical amplifier grown by solid source molecular beam epitaxy. The active region contains six Ga/sub 0.47/In/sub 0.53/As quantum wells, each containing three tensile strained GaAs delta layers. Simple ridge waveguide devices were fabricated with 8/spl deg/ angled facets. The internal gain is 26.5 dB for both the transverse electric and transverse magnetic polarizations at a wavelength of 1.55 μm and an injection current of 375 mA. The polarization sensitivity of the gain is less than 1 dB for a bandwidth of 45 nm, and the gain is nearly flat with a variation of less than 1 dB for a bandwidth of 20 nm. The saturation output power of these devices is 11 dBm. These results are reproducible and comparable to reports from more complex device designs.