Optimal Design And Fabrication Of The Polymer Planar Waveguide Optical Switches

The optical communication technology of using optical fiber as transmissionmedium is the necessary method of meeting the current rapid growth ofcommunication and data transmission. In recent years, with the application of datacommunication and the wavelength division multiplexing （WDM） technology, theexpansion function of the optical transmission network has been effectively improved.Optical switches and its arrays in WDM optical networks can play an important rolein many fields, including the switch protection, optical crossover interconnection,optical multiplexing, and routing, self-healing and so on. It is the core technology ofoptical cross connector （OXC） and optical add-drop multiplexer （OADM）.This paper made a research on both polymer planar waveguide thermo-optic（TO）and electro-optic（EO） switches. Firstly the research significance, progress andclassification of the optical switch, as well as the operating principle ofthermo/electro-optical switch were introduced; Then the core part of this paper wasintroduced, mainly including the following respects:1．A polymer/SiO₂hybrid waveguide Mach-Zehnder interferometer （MZI） typeof TO switch was experimentally demonstrated. The device could well transfer thesignal laser light with a wavelength of1550nm. The fabricated device exhibited apower consumption about26mW, extinction ratio about14dB, and rise time about340μs and fall time about356μs.2．How to reduce the power consumption of the single MZI polymer TO switchis one of the main research content in this paper. Firstly the size of the waveguide andthe electrode was optimized. The rise time of90μs and fall time of106μs wasreduced a lot compared to results before optimized. The extinction ratio measured14dB, and the power consumption of13.2mW has been reduced about50%comparedto the device without optimization. Afterwards, a simple and effective method,etching an air isolation groove, to reduce the power consumption of the polymer TOswitch was proposed. The optical field and thermal field for the structure with and without the air isolation groove were simulated. The power consumption of the deviceafter etching the air isolation groove was6.4mW, reducing45%compared to thepower consumption of11.6mW of the device without the air isolation groove.3．A MZI TO switch working at the wavelength of650nm based on thepolymer/SiO₂hybrid waveguide was experimentally demonstrated. The core materialwas the ultraviolet negative photoresist SU-8, and the under and upper cladding wereSiO₂and P（MMA-GMA）, respectively. The device was tested under the laser lightwith a wavelength of650nm. The fabricated switch exhibited an insert loss of9.7dBand rise time of about95μs and fall time of about215μs.4．The research on the inductively coupled plasma（ICP） etching was studied. Themorphology of the waveguides after etching were observed by virtue of images ofscanning electron microscope（SEM） and atomic force microscope （AFM）. The effectsof etching parameters such as Antenna Power, Bias Power, APC Press and Arconcentration on the vertical profile and surface roughness were also investigated.Through optimizing these parameters, a rib waveguide with vertical profile andsmoother surface was obtained. Three typical electro-optic materials were studied. Atlast, a core-modulating and a cladding-modulating EO switch based on DR1/PMMAwere fabricated and tested.