Opto-mechanics In Integrated Optical Waveguides And Its Applications In Optical Signal Processing

With the coming of high speed information age, optical communication network is achieving great development. On one hand, the communication capacity of the network link is getting improved greatly. On the other hand, increasing the integration density of devices and communication capacity, high speed, tunability, configurability, flexibility, versatility are the development trends of the signal processing of the network nodes. Opto-mechanical effects on the objects under the action of light, can produce the change of the momentum. By utilizing opto-mechanics one can control light using light indirectly. This makes tunable optical signal processing possible. Opto-mechanics in integrated optical waveguides has great potential for optical signal processing in the aspects of integration, tunability, configurability, versatility.In this thesis, opto-mechanics in integrated optical waveguides and its applications in optical signal processing are investigated, including the basic theory of opto-mechanics in integrated optical waveguides, an optical switch based on opto-mechanics, and an optically-controlled reconfigurable tunable demodulator. The contents are as follows:(1) The basic theory and characteristics of opto-mechanics(optical gradient force and radiation force) in integrated optical waveguides are analyzed. Potential applications of opto-mechanics in integrated optical waveguides for optical signal processing are discussed.(2) An optical switch based on opto-mechanics in integrated optical waveguides is proposed and designed. Opto-mechanics in integrated optical waveguide causes the deformation of the optical waveguide, thus changing the effective refractive index of the entire optical waveguides. The change of the effective refractive index of the waveguides causes the coupling length of the waveguide. Therefore the output signal can be tunably controlled. An optical switch based on opto-mechanics in integrated optical waveguides is numerically investigated. An optical switch based on graphene is also proposed and simulated.(3) An optically-controlled tunable DQPSK demodulator based on opto-mechanics in integrated optical waveguides is proposed and designed. The mode properties and the tunable performance of the DQPSK demodulator are simulated. The fabrication method of the demodulator waveguides is discussed. The demodulation performance of two different structures(double-clamped nanostring and cantilever nanostring) is compared. Furthermore, the proposed tunable demodulator can be developed to enable baudrate reconfigurable DQPSK demodulator by incorporating the structure of optical switch based on opto-mechanics. 10-Gbaud, 20-Gbaud and 40-Gbaud baudrate reconfigurable DQPSK demodulation are discussed and the performance of the demodulation is analyzed.