| The research of LD pumped solid laser is making great progress as LD with high efficiency and high power progresses. Because the LD pumped solid laser has so many virtues, for example high efficiency, high stability, narrow line width, long life time and small outline and so on, it has been utility instrument in many field such as laser medical, optical storage, laser rangefinder, optical spectrum analysis etc..LD pumped solid laser system is researched in this paper. The factors which influence the noise of optical output power is pointed out. And the resolvent of"green problem"is analysised. We used Nd:YVO4 as laser crystal and KTP as double frequency cystal in the experiment. By the way of double refraction effect we get an optical filter to make the laser system operate with single longitudinal mode. When the power of pumped light is 500mW, we gain the freen light which's power is 21mW. The noise of optical power is less than 0.6%. We can draw a conclusion that the noise of the double refraction mode laser system depends on the exact temperature control in the experiment.The PID method which is applied to temperature control is introduced. And the performance of several type of temperature sensor is compared. We designed two sets of current driver and temperature control circuit. They both provide the function of stable current driver, over current protection, high speed modulation etc. They also provide precision temperature control using negative temperature coefficient resistance and TEC. The system constituted by separate electronical components is low cost and can be assembled by functional modules more flexibly. The laser system temperature stability is less than 0.03℃under its control. The system constituted by import module can be designed in a small outline printed circuit board and it also has high reliability. The laser system temperature stability is less than 0.02℃under its control. They are very important to make the laser system operate with low noise output. |
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