Basic studies on efficient parametric image-upconversion of 10<micrn>m band into the visible.

研究结果如下：1.以铯原子为非线性介质，6d^2D3/2能级为双光子共振能级，差频产生为转换过程的系统效率最高。结果表明，铯蒸气电池的温度有可能降低几百度，并提出了基于热管炉以外的原理实现电池的可能性.理论计算表明，该系统无需任何缓冲气体即可实现共线相位匹配。在相位匹配条件下，计算了系统的接收角.在实验基础上研制的塞西姆蒸气室经测试是安全的。然而，该电池允许泄漏的蒸汽，使第二个电池正在建设。4.最后，对制约系统效率的双光子吸收进行了估算，完成了10 m波段到可见光波段的高效参量图像上转换的大部分基础研究<micrn>。图像上转换的实验可以在短时间内完成。

The summerized results are follows.1. The system utilizing cesium vapor as nonlinear medium, level 6d^2D 3/2 as Two-photon resonant level and difference frequency generation as conversion process will be the most efficient. The result indicates that lowering temperature of cesium vapor cell will be possible by several hundreds degree and it suggests the possibility of realizing a cell based on the principle other than heat pipe oven.2. In the above system collinear phase matching can be realized without any buffer gas according to theoretical calculation. Under the phase match condition the acceptance angle of the system is calculated.3. A secium vapor cell made on experimental basis has been tested and found to be safe. However, the cell permitted the leakage of the vapor, so that the second cell is being constructed.4. Two photon absorption which might restrict the efficiency of the system has been estimated.In conclusion, most of the basic studies on efficient parametric imageupconversion of 10<micrn>m band into the visible wavelength range has been accomplished. The experiment of the image upconversion can be performed shortly.