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甲醇（ＣＨ３ＯＨ）分子是常用的ＦＩＲ激活介质，具有很特别的光谱特征．而小型光泵脉冲亚毫米波激光器是近年才发展起来的新技术，作者已经成功地研制出管长为１０～２０ｃｍ的ＣＨ３ＯＨＦＩＲ激光器，并获得谱线．本文利用ＣＨ３ＯＨ分子能级表编制成数据库管理程序，对光泵ＣＨ３ＯＨ亚毫米波激光进行计算．代入ＣＯ２－９Ｐ（１６）线振动吸收跃迁的条件及相应的亚毫米波纯转动跃迁所受的跃迁选择条件，将泵频偏限制在±０．００３０ｃｍ－１范围内，可推算出，当亚毫米波波长为９１８μｍ（对应波数１０．８９３２３ｃｍ－１）时，有对应的能级跃迁：Ａ，ｇｒ，０，０；１０→ｃｏ，０，０；１１ｇｒ，０，１；１０→ｇｒ，０，０；１０泵频偏为－０．００２２４ｃｍ－１，其跃迁属基态反转的三能级跃迁，这种跃迁比激发态反转的三能级跃迁更不易得到，效率比较低．根据跃迁选择定则和ＣＨ３ＯＨ的分子参数，可计算出该跃迁的偶极矩阵元μ，单位体积内参与激光过程的有效分子数Ｎｖ，横向弛豫时间Ｔａ，纵向弛豫时间Ｔｂ和起始光强Ｉｓ０等参数．选定工作参数后，整个计算过程可由计算机完成．得出以下结果：１．亚毫米波激射呈现双峰形状，这是由于在强泵浦电场作用下，ＣＨ３ＯＨ分子能级出现?
Methanol (CH3OH) is a common FIR activator with very specific spectral characteristics. The small optical pump pulse sub-millimeter-wave laser is only developed in recent years, new technology, the author has successfully developed a tube length of 10 ~ 20cm CH3OHFIR laser, and get the spectrum. In this paper, CH3OH molecular energy level table compiled database management procedures, optical pumping CH3OH submillimeter laser calculation. Substituting the conditions for the absorption transition of the CO2-9P (16) line and the transition selection conditions for the corresponding submillimeter purely rotational transition, the pump frequency deviation is limited within the range of ± 0.0030cm-1, A millimeter wave with a wavelength of 918 μm (corresponding to a wave number of 10.89323 cm -1) has corresponding energy level transitions: A, gr, 0,0; 10 → co, 0,0; 11gr, 0,1; 10 → gr, 0 , 0; 10 The pump frequency deviation is -0.00224cm-1, and its transition is a three-level transition with ground-state inversion. This transition is more difficult to obtain than the three-level transition with excited-state inversion, and its efficiency is relatively low. According to the transition rule and CH3OH molecular parameters, we can calculate the dipole matrix element μ of the transition, the effective number of molecules Nv, the transverse relaxation time Ta, the longitudinal relaxation time Tb and the starting light Strong Is0 and other parameters. After selecting the working parameters, the whole calculation process can be completed by the computer. The following results were obtained: 1. The sub-millimeter wave lasing presents a bimodal shape, which is due to the CH3OH molecular level appearing under the action of a strong pumping electric field.