Microphotonics

Abstract: In this chapter, after presenting a brief review of the various types of optical waveguides, we outline the key principles and parameters which describe and define the operation of optical waveguides and fibres The ways in which propagation through optical fibres affects the properties of the guided waves are discussed, including dispersion and non linear effects Power transfer between propagating waves is essential to the operation of a number of components and the fundamentals of coupling theory are reviewed In summary, the theory given provides the foundation for understanding the detailed operation of a wide variety of optical components and systems based on optical fibre technology

Abstract: This work presents our recent progress in the development of an Si wire waveguiding system for microphotonics devices. The Si wire waveguide promises size reduction and high-density integration of optical circuits due to its strong light confinement. However, large connection and propagation losses had been serious problems. We solved these problems by using a spot-size converter and improving the microfabrication technology. As a result, propagation losses as low as 2.8 dB/cm for a 400/spl times/200 nm waveguide and a coupling loss of 0.5 dB per connection were obtained. As we have the technologies for the fabrication of complex, practical optical devices using Si wire waveguides, we used them to make microphotonics devices, such as a ring resonator and lattice filter. The devices we made exhibit excellent characteristics because of the microfabrication with the precision of a few nanometers. We have also demonstrated that Si wire waveguides have great potential for use in nonlinear optical devices.