Integrated optical demultiplexing and receiving device based on one-mirror-inclined three-mirror cavity (OMITMiC) structure, or OMITMiC wavelength-selective photodetector, is a kind of novel integrated multifunction optoelectronic device which was proposed in 1996 and first realized with GaAs-based materials for short wavelength (less than 1 m) operation in 2001. Recently, after great efforts on developing controllable self-retreating dynamic mask (CSRDM) wet etching method for InP-based epitaxial layer and low temperature InP/GaAs wafer bonding technique, such a device operating at long wavelength region (1550nm) had also been successfully demonstrated and the measurement results shown that it features high-speed (12GHz with a mesa area of 40 36 m 2 ), high quantum efficiency (66%~78.4%), ultra-narrow spectral linewidth (0.6 nm) and wide range tuning (more than 10 nm ) simultaneously. In addition, a long wavelength monolithic OMITMiC photodetector with GaInNAs absorption layer has also been demonstrated. These achievements could have a significant impact on wavelength-division-multiplexed (WDM) optical fiber transmission systems and networks.