| In this paper, dual Temperature Control (TC) of External Cavity Semiconductor Diodes (ECLD) is mostly studied, and the voltage regulator, which provides support voltages for the intelligent light source is developed.The main factors to influence stability of ECLD are drift of working temperature and changes of driving current. First, when temperature of ECLD inside increases, the output power decreases. And temperature being not stable may cause mode hop, which will highly affect the stability of ECLD. Second, the threshold current of ECLD increases along with temperature rising, and the parallel translation of ECLD's characteristic curve basically follows the change of temperature. In addition, working in excessively high temperature for a long time may cause aging or even damage of ECLD. Therefore, it is very important to strictly control the temperature of ECLD.The research object of this experiment is intelligent light source based on ECLD. The structure of dual TC of LD as well as entire intelligent light source is composed of two fixed value, closed loop, negative feedback systems of TC. One is achieved by the analog circuit with PID control theory; and the other is achieved by system based on micro controller. The experiment result indicates that the precision of temperature control of intelligent light source is±0.5℃and PID temperature control of LD can reach±0.03℃. In addition, an improving control project based on ARM is introduced, which makes the ECLD's servo circuit more accurate, efficient and abbreviated.Voltage regulator of intelligent light source system is high stability, double polarities and multi-output, which provides the voltages for the whole system consists of frequency stabilization servo circuit, temperature control circuit, constant source and wave tuning circuit. Its output include±5V,±8V,±12V,±15V, and its error is less than±0.02V.In application research of ECLD, the ECLD with temperature control is more consistently dependable. |
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