Research on developement of the laser excited by a semiconductor diode in laser beam lithography

通过对掺Nd的LiNb03 （LN）的吸收光谱和光致发光光谱的测量，我们得到了以下结果：(1)比较了掺量为1和3 %的Nd离子的两种LN亚速率的上述效率。结果表明，在TM偏振光入射下，后者具有最大的光致发光。(2)它们的光谱表现出温度依赖性，当温度升高到90 C时，其亮度随温度升高而升高，但从90 C下降到150 C。(3)对于3% nd掺杂的LN，我们只观察到自发发射，而没有达到总体反转。其次，从实验和计算两个方面对KNb03晶体中二次谐波产生（SHG）过程产生的蓝光进行了研究。结果如下：(1)由于激光二极管存在像散像差，对传统的相位匹配进行了改进，使其包含聚焦光光束半径的依赖关系。(2)以上像差使相匹配波长向波长较长的一侧偏移。在室温下，由于像散像的存在，晶体X-Y平面上不存在相匹配角。(3)相对于激光二极管，在12.5℃的温度下，在光束半径为100mum，激光波长为863.5nm的相位匹配条件下，将KNb03的SHG晶体保持在38.6℃的温度下，产生蓝光。

From the measurement on the absorption and the photoluminecent spectrums of Nd-doped LiNb03 (LN), we have obtained the following results(1) Two LN subtsrates, in which the Nd ion of 1 and 3 weight % had been doped, respectively, were compared on above efficiencies. As a result, the latter had the greatest photoluminecence of in the incidence of TM polarized light.(2) Their spectrums were found to exhibit the temperture dependence such that the magnitude was raised withthe increase of temperature untill 90ﾟ C, but dcreased from 90ﾟ C to 150ﾟ C.(3) For the 3% Nd-dopepd LN, we had observed only the spontaneous emission, not atainning to the population inversion.Next, the blue light generation due to the second harmonic generation (SHG) process in KNb03 crystal have been examined from both aspects of experiment and calculation. The results are as follows.(1) Due to the presence of astigamatic aberration in the laser diode, the conventional phase matching was modified so as to include the beam radius dependence of a focusing light.(2) Above aberration makes the phase matching wavelength shift into the side of longer wavelength. At room temperature, the phase matching angles are not existed in the crystalographic X-Y plane, due to the astigmatic aberration.(3) The blue light was occured in the phase matching conditions of the beam radius of 100mum, the lasing wavelength of 863.5nm under peltier-cooling of 12.5ﾟ C with respect to a laser diode, and keeping the SHG crystal of KNb03 at the temperature of 38.6ﾟ C.