Integration of waveguide type wavelength demultiplexing photodetectors by selective intermixing of InGaAs/InGaAsP quantum well structures

Abstract

Wavelength demultiplexing photodetectors was fabricated using selective intermixing of InGaAs/InGaAsP multi-quantum well (MQW) structure. As InGaAs/InGaAsP MQW with U-InP cladding layer and U-InGaAs cap layer grown by metal organic chemical vapor deposition (MOCVD) was used for this experiment. Intermixing of InGaAs/InGaAsP MQW structure was done by a rapid thermal annealing after depositing SiO2 dielectric layer on the InGaAs cap layer by plasma-enhanced chemical vapor deposition (PECVD). Three sections of shorter-wavelength PD, absorber region and longer-wavelength PD lined up linearly and the front two regions were intermixed. Output current ratios of fabricated photodetectors at wavelengths of 1550 and 1480 nm were about 20dB and thus the photodetectors were proven to demultiplex both wavelengths.