New high speed long wavelength Al0.48In0.52As/Ga0.47In0.53As multiquantum well avalanche photodiodes

We report the operation of a new long-wavelength (λ=1.3µm) superlattice avalanche photodiode. The p⁺in⁺structure, grown by MBE, contains a 35 period Al0.48In0.52As (139Å)/Ga0.47In0.53As (139Å) multiquantum well In the i region. Dc and high frequency multiplications of 65 and 12 respectively have been measured; the dark current at unity gain is 70 nA. High speed of response with full widths at half maximum of 220 ps at a gain of 12 and the absence of tails are demonstrated, indicating that carrier pile-up in the wells is negligible.