大口径倍频晶体高精度温控装置的研制

非临界相位匹配条件下，为保证大口径倍频晶体具有较高的温度稳定性与一致性，在全口径范围内实现最优的倍频转换效率，设计了一种采用电加热方法进行高精度温度控制的装置。在装置设计中，充分考虑倍频晶体导热系数小、形状薄而大的特点，通过热传导加热倍频晶体，并同时加热装置其他部分，形成自然对流，均衡晶体温度。通过仿真和实验得到该装置温度分布的整体规律，得到在不同加热长度下，晶体稳定温度及稳定所需时长随晶体材料导热系数变化的规律。实验和仿真均表明:该装置能加热80 mm口径的倍频晶体至目标温度，并将其温度一致性控制在0.15℃范围内。

Development of high precision temperature control device for large aperture frequency doubling crystal

In noncritical phase matching condition, it is necessary to precisely control the stability and uniformity of the crystal temperature in full aperture. A device using resistive heater to control the temperature of the large aperture crystal was introduced. Taking full account of the low thermal conductivity and large aperture of the crystal, it was heated by thermal conduction and the natural convection of the inner air, which was heated up at the same time for temperature balancing. The characteristics of temperature distribution of the device were studied. Through experiments and simulations analysis, it was found that the crystal temperature of steady state and the necessary heating time varied with the heating length and the thermal conductivity of the crystal material. The result shows the practicability of the thermal control of the crystal with the aperture of 80 mm. The temperature difference of the crystal, in steady state, could be controlled within 0.15℃.