[OPTICAL REVIEW Vol. 6, No. 5 (1999) 459-463]
Characteristics of InAlGaAs/InAlAs Superlattice Avalanche Photodiodes for Ultra-low Optical Power Detection in the Near Infrared
Yasunori SAITO,1 Tomoyuki MARUYAMA,2 Hideaki YAMAKI,1,3 Fumitoshi KOBAYASHI,1 Takuya D. KAWAHARA,1 Akio NOMURA1 and Mitsuyoshi TANAKA2
1Department of Information Engineering, Shinshu University, 500, Wakasato, Nagano, Nagano, 380-8553 Japan, 2R & D Office 5, Hioki E. E. Corporation, 81, Koizumi, Ueda, Nagano, 386-1192 Japan
(Received April 12, 1999; Accepted June 29, 1999)
Static characteristics of two different structured InAlGaAs/InAlAs superlattice avalanche photodiodes (SLAPDs) cooled by liquid nitrogen were evaluated at a wavelength of 1.5 μm. The dark current of the SLAPD having a thick superlattice layer of 0.504 μm was 5×10-13 A. This was successively reduced by four orders of magnitude compared to that of the thin layer SLAPD of 0.231 μm at a breakdown voltage of around 20 V. The thickened layer was effective in suppressing tunneling dark current. An output current of 1.7×10-12 A at a bias voltage of 15 V was measured for an optical input with a wavelength of 1.5 μm and a signal power of 1×10-12 W. This showed a sharp distinction from the dark current.
Key words : avalanche photodiode, superlattice, InAlGaAs/InAlAs, dark current, ultra-low optical power, near infrared
3Present Address: Toyokawa Administrative Center, Minolta
Company, Ltd., 1-8, Kanayanishi-Machi, Toyokawa, Aichi, 442-8558 Japan
saitoh@cs.shinshu-u.ac.jp