OPTICAL DETECTOR FOR WAVELENGTH DIVISION MULTIPLEXING SYSTEM AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: An optical detector for a wavelength division multiplexing system and a method for fabricating the same are provided to minimize a volume and a dependency of a polarized light in an optical detector having an optical wavelength bandpass filter and an optical detecting device. CONSTITUTION: A n-InP layer(44), a n-InGaAs layer(43), and a p-InP layer(41) are deposited on a n-InP substrate(45), thereby forming an optical detecting device having a PIN(positive intrinsic negative) junction structure. A metal thin film such as an Au/Au-Sn is coated on the optical detecting device. An electrode(46) is formed on the lower surface of the substrate. An optical wavelength bandpass filter(47) is formed on the light receiving surface of the substrate to transmit only an optical signal of a center wavelength among an input optical signals input. The optical detecting device outputs a predetermined electrical signal, according to the intensity of radiation and the strength of the optical signal transmitting the optical wavelength bandpass filter. The optical detecting device is a PIN photodiode.