Study Of Polymer Thermo-optic Waveguide Devices

The information and the network are developing in a high-speed way andbecome more and more popular in this world. The development of the network haschanged the status of the communication industry. Nowadays, the communication hasalready penetrated into every corner in our life. The optical fiber has many advantages,such as low loss, large bandwidth, large capacity and strong anti-interference ability;so compared with traditional communication system, filer communication system hasadvantages of low loss, large bandwidth, large capacity and strong anti-interferenceability. The extensive utilizing of wavelength-division multiplexing technology(WDM) in fiber system has enlarged the capacity of the fiber communication systemeffectively. Optical switch and optical switch array have played important roles ofoptimizing optical domain, self-healing and domain routing, and also are the keydevices of optical cross connection (OXC) and optical add-drop multiplexer (OADM)system. Compared with inorganic materials, organic materials have advantages ofvariety, simple technology, low cost and easy to integrate, therefore it is extensivelyused in the fabricating of optical switch.This paper has done many work aimed at design, fabrication and measurement ofpolymer thermo-optic switch based on silicon substrate. Firstly, the uses and kinds ofoptical switches, the material selection and the development of thermo-optic switcheshave been introduced, and then the theory of thermo-optic effect, asymmetricthree-layer planar waveguide, rectangular waveguide and MMI-(MZI) type planarwaveguide has been explained in detail.The main contents include the following aspects.1. A Y branch thermo-optic switch has been designed and fabricated utilizingSiO2/polymer hybrid structure. Utilizing silica as the low cladding layer,P(MMA-GMA) as the core layer, the device has been fabricated. Then theperformance of the device has been tested under the fiber-waveguide coupling testplatform constructed in our laboratory. The experimental results indicate that theoptical insertion loss and extinction ratio of the fabricated switch are12dB and18dB,respectively. The rise time and the fall time are120μs and110μs respectively, andthe driving power is130mW.2. Using silicon as substrate, P(MM-GMA) and fiber-coupling test platform, the2×2MMI-MZI polymer thermo-optic switch has been fabricated and testedrespectively. We have got good near-field optical output and with the switch power of 25mW, the rise time of380μs, the fall time of400μs.3. This part has been mainly conducted the research aimed at the three-dimensionalpolymer thermo-optic switch based on vertical coupling structure. The MMI beamsplitter has been selected as the structure of lower waveguide. First, the optical fieldof1×2,1×3,1×4beam splitter has been simulated and analyzed, and then thefabrication process of three-dimensional thermo-optic device based on verticalcoupling structure using silicon as substrate and P(MMA-GMA) as the core layer hasintroduced detailedly. In the end, we have got the near-field optical output and timeresponse curve of triangular wave and rectangular wave, and the optical insertion lossis about25dB.