The Research Of All-Optical Switches Based On Compound Semiconductor Materials

With the great increase of information traffic, all-optical transmission network has become the future development trend of optical network. The optical switches and optical switch arrays are the key devices in the optical cross-connect equipments (OXC) and optical add and drop multiplexing equipments (OADM) ,which are the important components in the all-optical network. The development of all-optical network technology, especially optical time-division multiplexing technology, requires much faster optical switches.The traditional optical switches, such as MEMS optical switches, thermo-optical switches, liquid crystal switches, cannot cope with the requirement of ultral-fast speed in the all-optical network. However, the all-optical switch, which is modulated directly by controlling pulses, can overcome the limitations of "electronic bottleneck", and reach picosecond switching time, so it is very attractive in the ultral-fast optical switch research.In this dissertation, the working mechanism of the optically activated switch is analyzed. The model of photon-induced refractive index change based on GaAs materials is presented briefly, then the model based on GaAs/AIGaAs quantum wells materials is deeply analyzed by treating the effects of photon-excited carriers self-consistently. Furthermore, the propagation characteristics of multi-quantum well waveguide is invested, and the low-loss multi-quantum well rib waveguide deeply etched is also designed by using the spectral index method.The researches of switch structure focus on the suppression of multi-mode interference (SMI) by FD-BPM simulation. The SMI all-optical switch, which has the advantages of simple structure, small size, and capability to be monolithically integrated into large optical switch arrays is analyzed in detail.We have fabricated the all-optical switches based on GaAs epitaxial materials by using the semiconductor device fabrication technology. The fabrication experience and detailed parameters are also summarized in thispaper. A series of near-field images of the output channels has been collected, and analyzed with Gaussian curve fit method. The testing results show that the extinction ratio of SMI all-optical switch based GaAs epitaxial materials can reach 8dB, and the experimental phenomena of M-Z all-optical switch can be observed too. Beside, we have also made experiments on all-optical switches fabricated on GaAs/AIGaAs quantum wells materials.