液晶波前校正器特性研究

利用808 nm大功率连续激光器研究了液晶的光功率承受特性结果表明,当功率密度为133 W/cm2时,液晶还能保持原有的光学调制特性,而且可以长时间稳定工作测定了液晶的波长色散特性,发现,随着波长的增加Δn值逐渐减少,近紫外300~400 nm波段Δn变化47％,而在400~780 nm变化量为28％,在780~900 nm Δn变化了2％还研究了温度对液晶波前校正器衍射效率的影响,随着温度的升高Δn逐渐减小,当温度从10℃升到90℃时,对于16台阶菲涅耳透镜,衍射效率下降了70%；但当温度在20℃变化10℃时,对4台阶菲涅耳透镜衍射效率最大变化量为1.7%,而对16台阶菲涅耳透镜,衍射效率降低了1.2%.

Characteristics of Liquid Crystal Wavefront Corrector

The durability of the laser power is considered with an 808nm wavelength continuous high power laser.It is shown that the liquid crystal does not take place the phase transition while the laser power density is 133W/cm2,and it can hold the liquid crystal state at long time.The dispersion of the liquid crystal wavefront corrector is measured and discussed.It indicates that as the wavelength increases,the birefringence Δn decreases.The changes of Δn are 47%,28%,and 2% at 300~400 nm,400~780nm,and 780~900nm respectively.The effect of the temperature on the diffraction efficiency of the liquid crystal wavefront corrector is also analyzed.The birefringence of the liquid crystal as functions of the temperature is measured.It is shown that the birefringence reduces while the temperature increases.The diffraction efficiency decreases from 98.7% to 27.2% while the temperature increases from 10 to 90 centigrade for 16 quantified levels.However,the diffraction efficiency just decreases 1.2% while the temperature vibrates at 20 centigrade with 10 centigrade.