| The rapid development of the dense wavelength division multiplexing (DWDM) optical communication network created a high demand for more powerful and better performance optical devices. The temperature characteristics of optical integrated devices and temperature control were the key points of building a steady and reliable optical network.The thesis designed three kinds of wide range temperature control systems employing semiconductor refrigeration technique, such as an entirely sealed system, a half sealed system and a clamping system. The temperature distribution inside the systems was analyzed with the finite element method with a concern on their uniformities. The results of simulation indicated that, for the entirely sealed system, if only one refrigeration chip with the power of 4 watt was used, the difference between the highest and the lowest temperature was about 1.7℃. If two refrigeration chips with respective power of 2 watt were used, the difference of temperature was about 0.5℃. And if four refrigeration chips with respective power of one watt were used, the difference of temperature was about 0.24℃. For the half sealed system, the difference of temperature was from about 1.6℃to 1.8℃. For the clamping system, if there was no refrigeration chips, the temperature of about 70 percent area of the optical integrated device was affected by the heat resource, and if there were two refrigeration chips, the temperature of only about 30 percent area near the heat resource was affected and other area remained 25℃.At the same time, a control circuit was constructed in this thesis employing a monolithic thermocouple amplifier with cold junction compensation AD595, a complete 12-bit A/D converter AD574, a 8-bit MCU P89C61X2BN, a 8-bit D/A converter DAC0808 and a high-voltage and high-current operational amplifier OPA547. It can scanned the temperature from—10℃to 60℃. The system had the advantages of small shape, convenient usage, no pollution and low cost. |
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