We investigated a 1.5-μm-wavelength InAs-based quantum-dot (QD) absorption layer for high-speed and high-sensitivity photodetectors in advanced optical-fiber communications. The photodetector, which contained 20 stacked absorption layers of InAs/InGaAlAs QDs using the straincompensation technique, exhibited a high absorption coefficient, avalanche multiplication effect, and a low dark current. It could operate at a low bias voltage for a p-type-intrinsic-n-type (PIN) diode structure. We expect that the 3-dB bandwidth at a low bias voltage would be approximately 50 GHz, and that the gain and bandwidth product in the avalanche multiplication region would be 150GHz at a high bias voltage.
ASJC Scopus subject areas
- Physics and Astronomy(all)