Research Of Optical Switch And Photodetector In Optical Interconnection

It is a common sense that optical interconnection and optical switching will replace electronic interconnection and switching as its advantages of high transmission capability, high speed, no interfere, low loss, powerful I/O function. Besides, optical interconnection and optical switching can be connected with electric system commendably by integrated receiving module, light-emitting module, space light modulator and so on. Thus we can make full use of electric system to get powerful logic processing capacity and realize complicated system function. Optical interconnection and optical switching include two aspects of technologies, and one of them is apparatus technology, which is made up of light-emitting technology, light-modulating technology, light-receiving technology, optical switch technology and micro-optic apparatus technology etc., and the other is network-constituting technology that is composed of network-topology design and optics-implement technology. The developing history of optical interconnection and optical switching is that of photoelectric apparatus in nature. The implement of optical interconnection and optical switching lies on the development of optical switch, photodetector (PD), laser etc.. In the paper, optical switch and photodetector will be discussed. We will bring forward a novel free-space fiber switch, which is independent of polarization, and it obtains line-polarized light by modulating incidence light that is transmitted in optical route and is comeback in fan-out, thus the polarization dependent loss in free-space fiber switch which is caused by each component's polarizing accumulation will be minished. The loss can change the state of polarization. In the paper, the principle and matrix description of the switch is expounded, and the aplanatism of signal lights is also testified, and the insert loss (IL) and polarization dependent loss (PDL) is analysed. Then, fixing and debugging for optical switch is discussed. It is a luciferous foreground for silicon photodetector because of silicon material abundant resource and being compatible primely with integrate circuit. Whereas, silicon is an indirect gap material, which causes the performances of silicon photodetector present any deficiency. In the paper, we will overcome the problem from fabricating-technics and configuration of apparatus. We will discuss three integrate technics in first, and then modify the technics in some sort for enhancing the performances of the silicon photodetector. On another hand, we will bring forward a resonant-cavity-enhanced (RCE) photodetector. A Fabry-Perot (F-P) cavity is shaped by growing distribute Bragg reflection (DBR) in two ends of apparatus. Optical field intensity in the cavity will enhance consumedly as resonate-enhanced effect, thus photodetector can achieve higher quantum efficiency and bandwidth in the instance of thiner absorb layer. The performances of the photodetector will be analysed in the paper, and be compared with conventional photodetector. In the end, fabricating process of a simple RCE photodetector is discussed.