Optoelectronic properties of InGaAs/InGaAsP multiple-quantum-well waveguide detectors

The performance of InGaAs/InGaAsP multiple-quantum-well material as the absorbing medium in waveguide detectors is discussed. No deleterious saturation effects were observed up to an absorbed power of approximately 1 mW, with strong enough absorption for a four-well separate confinement heterostructure to provide >or=80% quantum efficiency for lengths at least as short as 114 mu m. The frequency response up to 5 GHz shows only a simple parasitic-limited rolloff which matches the measured impedance. These results provide sound evidence that the carrier trapping problem in this quantum-well material combination is much less serious than that in other material systems. This has important consequences not only for quantum-well field effect optical devices, but also for photonic integration, since the same quantum-well layers can simultaneously serve as a gain medium and as a detecting medium.<>