Abstract

In this work we describe an optical amplifier fabricated from a strained-layer multiple quantum well laser diode. The amplifier has a small signal gain in excess of 25 dB and a 3-dB saturation output power (P_3dB) exceeding 25 mW. In general, amplifiers fabricated from bulk epilayer, buried heterostructure devices have high gain per unit length and small saturation output power. A benchmark for such an amplifier operating at 1.5μm wavelength is a 300 μm long buried heterostructure device, which had small-signal gain of 24.5 dB with P_3dB of 9 mW.[1] Optical amplifiers fabricated from multiple quantum well laser diodes have significantly higher values of P_3dB, at the expense of greatly reduced gain. [2,3] The properties of the multiple quantum well optical amplifiers arise, in large part, from the small mode confinement factors, Γ, for these devices, which reduce the gain (proportional to Γ) and increase P_3dB (proportional to 1/Γ). Thus, a 625 μm long multiple quantum well amplifier with Γ = 0.05 demonstrated small-signal gain of 19 dB and P_3dB of 42 mW. [2] By reducing Γ to 0.02, a 500 μm long multiple quantum well device with P_3dB of 115 mW, but with gain of only 8 dB, was reported. [3]

© 1990 Optical Society of America