Research On Flat Spectral Response Of Si-based Polymer Arrayed Waveguide Grating Devices

As society is entering into an information age, the rapid increase of global communication services, it will be a certain tendency of the broadband integrated services network, which is of the increase of speed and the enlargement of capacity in modern communication networks. The all-optical network bases on WDM system is full of agility and environmental stability, and perfectly fit into optical fiber communication systems in the future. The application of the wavelength division multiplexing (WDM) technology could solve the problem about the massive increase of speed and the enlargement of capacity broadband information. AWG devices possess some advantages, such as easy optical integrating, narrow wavelength spacing, much more signal channels and compact structure. Also, AWG devices are the most parts of optical add/drop multiplexer (OADM) and optical cross connectors (OXC) modules in optical fiber network. Polymer AWG's excellent particular features, such as low cost, simple fabrication process, low propagation loss, small birefringence and easy control of the refractive index, evoke the researchers'interest. Therefore, the WDM technology has already become one of the most important technologies in optical fiber communication.In this thesis, the optimization and fabrication of two fluorinated polymer/Si AWG multiplexers with flattened response are reported, which consist of 17×17- channels. The wavelength spacing of the AWGs is 0.8nm, the insertion loss of is above–13.4dB. the crosstalk of AWG is–20dB. The main contents are as follows:1. The research history and current situation about AWG are reviewed, and put forward the need of studying polymer AWG, and the research history and current situation about AWG with flattened response are reviewed.2. Some principle theories and academic formulae about AWG were given out. And some important characteristics about AWG are discussed and analyzed, in order to offer theoretic basis for following parameter optimization and layout design.3. we present a technique of obtain flattened response. First, we optimize the parameters of the AWG device with flattened response, and finish design of an AWG with flattened response.4. Effect of bending on transmission characteristics and manufacturing errors of arrayed waveguide grating multiplexers are discussed and analyzed carefully.5. A 17-channel AWG device with flattened response operating around the 1550.918 nm wavelength has been designed and fabricated using highly fluorinated poly ethers based upon the preceding basic theory and technique method. The waveguide propagation loss is measured to be 0.67dB/cm by the cut-back method. The insertion loss is 6.7dB, crosstalk is–20dB, and free spectrum range FSR is 13.7652nm by the fiber-waveguide coupling method. In the central channel, the total loss is 13.4dB, and the 3-dB is about 0.476nm. The research about polymer AWG is being in the ascendant in the worldwide.Our following research will focus on further optimizing the device structure, synthesizing some lower loss polymer materials, improving manufacturing precision, We are devoting ourselves to fabricate the polymer AWG device with low loss, low crosstalk, low polarization-independence and with flattened responses.