GaInAsP/InP attenuator integrated waveguide photodetector (AIPD) based on the Franz-Keldysh effect

A waveguide photodetector monolithically integrated with an optical attenuator based on the Franz-Keldysh effect at the input section is proposed. The intrinsic sensitivity of the device without attenuation is 0.25 A/W. The effective sensitivity is reduced by applying the reverse bias at the attenuator section. The largest variable sensitivity range of 11 dB is realized at the reverse bias of 32 V.