Studyies On Integrated Demultiplexing Receivers For Dense Wavelength Division Multiplexing (DWDM) System

Since the Internet has been experiencing the explosive growth these years, it brought great pressure to the transmission network. The mass data which is rapidly growing up in the internet needs more and more bandwidth to transmit. Fortunately, the emergence of Wavelength Division Multiplexing technology solved the contradiction between the mass data and limited fibers. The Dense Wavelength-Division Multiplexing (DWDM) system could maturely provide much more bandwidth with the same amount of fibers. The DWDM which is a mature and more advanced optical communication technology has seized lots of attention from the Labs in the world. Detectors used for DWDM system, featuring for wavelength-selection, high quantum efficiency, high frequency respond and narrow spectral line width, have many applications. The main achievements and research works are listed as follows.1. Quantum efficiency and frequency respond of a monothically integrated InP p-i-n photodiode with GaAs Fabry-Perot filter (GaAs-DBRs/InP-PD) are researched in this thesis. Then the fabrication process of the GaAs-DBRs/InP-PD is studied in detail, which includes InP/GaAs heteroepitaxy growth, magnetron sputtering of metal coating method, fabrication technologies of photo-etching, and fabrication technologies of Pimples in/out. The monolithically integrated photodetectors are fabricated and tested. The device operates at a wavelength around 1566nm. The peak quantum efficiency more than 12%,3-dB spectral linewidth of 1.8nm, a 3dB bandwidth of 13GHz have been simultaneously obtained. 2. Quantum efficiency and frequency respond of dual-juction PIN RCE photo-detector are researched in this thesis. Then the heteroepitaxy growth and fabrication process are analyzed. The dual-junction PIN RCE photo-detectors are successfully prepared and tested. The device operates at a wavelength around 1500nm.The peak quantum efficiency about 70%, and a 3dB bandwidth of 17GHz has been obtained in this device.3. The basic structure and quantum efficiency of the wavelength selective monolithically integrated photo-detector array have been analyzed. Then the fabrication process of the multistep cavity, which includes the technologies of fabrication technologies photo-etching and the multistep cavity, is analyzed in detail. Then the wavelength selective monolithically integrated photo-detector array is fabricated and tested. The four cavity device operates at 1550nm for four channels with 10nm interval. The results show that the device has a good performance in spectrum.The dropped central wavelengths are 1538nm,1550nm,1559nm and 1570nm, and the quantum efficiencies are more than 15%. The spectral linewidth as narrow as 0.8nm, and a 3dB bandwidth of 9GHz are simutaniously obtained in the device.