Far infrared optically pumped SO2laser

CO2laser pumping of the SO2molecule has produced far infrared (FIR) lasing on three rotational lines in the ν1excited state. Complete line assignments have been derived for all of the observed transitions.     

中红外激光器功率稳定器技术

针对中红外光电探测器光谱响应度精确测量时, 要求提高中红外激光器功率稳定度这一问题。提出了一种对中红外激光器功率进行稳幅的方法, 基于声光调制器布拉格衍射原理、采用光反馈闭环控制技术实现了对中红外激器光功率的稳定控制。详细介绍了该方案的光路设计、控制电路原理及控制算法, 在此基础上研制了一种中红外激光功率稳定器。采用该功率稳定器对3.39 m He-Ne激光器的输出光进行了稳幅实验。结果表明, 该装置可将中红外激光器输出功率稳定度从8%提高到0.4%。可很好地满足中红外探测器光谱响应度测试的需要。     

Applications of high resolution spectroscopy to the identification of far-infrared laser emission from optically pumped13CH3OH

High-resolution infrared (IR) and far infrared (FIR) Fourier transform absorption spectra have been employed to investigate assignments of FIR laser lines reported from optically-pumped¹³CH₃OH. The spectroscopic measurements are used in conjunction with the reported IR pump and FIR laser frequencies to form closed combination loops for several systems, serving to confirm the assignments and in some cases to improve the accuracy of the FIR laser frequencies. Frequency predictions from combination differences are also presented for a number of potential new FIR laser lines.     

New infrared laser lines in argon, krypton, and xenon

Fourteen new infrared laser transitions in Ar, Kr, and Xe ranging from3.725 to 17.233 mum are reported. All of the Kr laser transitions and all but one of the Ar and Xe transitions have upper levels in thesordstate: the majority of the transitions satisfy the conditionDelta K = Delta J. Identification of a previously observed, unidentified laser line at 5.804 μm in Ar is given.     

光抽运甲基氟远红外激光器

一、引言 用CO_2激光抽运的远红外激光器诞生在1970年,至今已在30多种分子中获得了1000多条远红外激光谱线,波长范围从40微米到2毫米,复盖了整个远红外区。与电激励远红外激光器相比,光抽运的远红外激光器不存在放电起伏、热漂移和分子分解等现象。因此,具有单色性好,噪声低等优点,特别适用于通讯、雷达、等离子体诊断、光频标与光频测量、光谱学、天文学等领域。     

Far infrared stimulated emissions from CO2 laser excited dichloromethane

Six new far-infrared laser frequencies have been obtained in CO₂-laser excited dichloromethane. Competing transitions have enabled assignments to be made to the v₇ band.     

The vinyl bromide optically pumped far infrared laser: new largeoffset emissions

We present the results of a study on vinyl bromide in the search for new far infrared (FIR) laser lines. As the pump source, we use a CW waveguide CO₂ laser with a tunability of 290 MHz around each line in order to pump large offset vibrational transitions. As a consequence, we obtained 28 new FIR laser emissions; 24 of them have wavelengths greater than 500 μm and are, therefore, suitable to be used in high-field EPR spectroscopy. For each of the new lines, we give the wavelength, the offset of the pumping transition with respect to the center frequency of the CO₂ emission, the polarization relative to that of the pumping laser line, the operating pressure, and the relative intensity. We also present a catalog including data of all of the FIR laser lines observed from this molecule up to now     

A tunable far infrared laser

A continuously tunable far infrared (FIR) laser has been demonstrated; experimental results are presented. A high-pressure (10-12 atm) continuously tunable CO2TE laser is used to pump Raman transitions in CH3F; the generation of continuously tunable radiation in the250-300 mum wavelength range is reported. Accurate frequency and bandwidth measurements have been made and the FIR bandwidth in superradiant emission isapprox4-5GHz. Consequently, the generation of frequency tunable, subnanosecond pulses in the FIR appears feasible. The generation of tunable laser radiation from 150 to 1000 μm by stimulated Raman scattering should be possible using higher pump intensity and/or other gases.     

定向红外干扰系统中磷锗锌激光源的最新进展

高质量中红外激光源是定向红外干扰系统中的核心组件,与系统的作战效能密切相关。介绍了定向红外干扰系统中基于磷锗锌晶体的激光源的晶体特性、生长工艺、常用腔型和抽运源技术,详述了磷锗锌激光源的最新研究和应用进展,分析了制约磷锗锌激光源发展的技术瓶颈,并对磷锗锌激光源在定向红外干扰系统中的应用前景进行了展望。     

New infrared laser transitions in Ag II

We have observed seven infrared laser transitions when exciting a He discharge in a silver hollow cathode. To our knowledge, five of the seven laser transitions have not been reported previously in the literature.     

The identification of candidate transitions for optically pumped far infrared lasers: Methyl halides and D2O

Two hundred and forty-four candidate transitions for optically pumped far infrared lasers have been identified in C¹²H3F, C¹³H3F, C¹²D3F, C¹²H3Cl³⁵, C¹²H3Cl³⁷, C¹²H3Br⁷⁹, C¹²H3Br⁸¹, and D2O using as candidate pump lines, 781 in number, the isotopic forms of CO2, the sequence and hot bands of C¹²O2¹⁶, and the N2O bands. The dominant transition parameters responsible for strong emission from TEA, CW, and long pulse modes of operation were identified by a correlation between known experimental behavior and the pertinent transition parameters, the results being that strong TEA laser emission correlates with ground state population while strong CW and long pulse emission correlate with absorption coefficient. The candidate transitions were subsequently selected on the basis of these parameters using calculated transitions and assignments based on band data from high resolution laser-Stark spectroscopy and measured candidate pump frequencies.     

Analysis of CH3OH far infrared laser lines optically pumped by sequence band and isotopic CO2lasers

Assignments are presented for seven far infrared (FIR) laser lines of CH3OH pumped by theS-9P(31),18-10R(24),13-9R(26), and13-9P(16)CO2laser lines, plus an interesting speculation for the FIR line pumped by the18-9P(12)CO2line. Frequencies have been deduced to a substantially improved accuracy of ±0.001 cm^-1from IR and FIR spectroscopic combination differences for most of the assigned lines as well as three other predicted transitions. In addition, accurate frequencies are given for 13 predicted FIR laser transitions which are expected from the IR spectrum to be pumped by three¹⁶O¹²C¹⁸O laser lines.     

Hamiltonian of a Slightly Asymmetric Molecules with a Three Fold Internal Rotor and Its Applications to Optically Pumped FIR Lasers: Theoretical Aspects

In this paper, a Model of the Hamiltonian function is reviewed for the slightly asymmetric class of molecules, which is the most successful so far, according to our present knowledge. This model does not have the redundancy problem suffered by previous models. The observed frequencies are calculated to within experimental accuracy. In our subsequent papers we will show the application of this model for the prediction and quantum number assignments of optically pumped far infrared lasers and thereby increasing the possibility of new lines in the region of the spectrum which severely lacks enough monochromatic sources. We will also show that this model is capable of calculating even MMW transitions for the second excited state of methanol. All the previous models consider transitions up to the first excited torsional state.     

New possibilities for frequency stabilization of far infrared lasers

All spectrometers based on the use of a far infrared laser present the drawback of the laser frequency uncertainty. Even if the knowledge of the laser frequency is very precise, a shift of the laser cavity length is always present, limiting the spectrometer frequency accuracy to 500 kHz. The goal of this paper is to give a solution to this drawback in demonstrating the feasibility of a frequency stabilization of the far infrared laser.     

Theoretic model of myocardial revascularization by far infrared laser and experimental validation

A theoretic model of myocardial revascularization by a far infrared laser has been established and a quantificational rela- tionship between the aperture of laser channel and parameters of laser has been concluded according to thermodynamics and the law of interaction of far infrared laser and myocardium. The experiment of a carbon dioxide laser revascularization in porcine myocardium has been done for different laser powers and irradiation time. The relative errors between experi- mental result and theoret...     

Nonlinear level crossing in the infrared transitions of optically pumped far infrared laser media

In conjunction with the Stark field induced power enhancement in optically pumped far infrared lasers, absorption transitions in a degenerate two level system under the influence of an weak static Stark field have been analyed. A third order theory to the density matrix formalism leads to zero field level crossing signals for absorption in rate equation approximation and in Doppler limit. For fast relaxation among Zeeman sublevels, the zero field level crossing signal arises from population effect. Optoacoustic measurements have been carried out on the ν₅,^qQ(16,8) absorption line of CH₃OH which produces the familiar 119-μm laser with the CO₂ 9P(36) pump line. The optoacoustic absorption signals observed are well reproduced by the theoretical expression.     

量子级联激光器的发展及其应用

量子级联激光器作为新近出现的全固化小型理想中远红外激光源,引起了人们极大的兴趣,本文介绍了量子级联激光器的发展、应用状况及一些可能的应用范围。     

Assignments of far-infrared laser lines in the CO-stretching state of 0–18 methanol

Far-infrared (FIR) laser and infrared pump transitions of the O-18 isotopic species of methanol have been assigned for a number of CO₂ laser pump lines with the aid of high-resolution Fourier transform spectra in the FIR and CO-stretch band regions. The structures of the FIR laser energy level systems and the transition assignments were established through the use of closed transition combination loops, which also yield improved accuracies for the FIR laser wavenumbers.     

Submillimeter laser action of CW optically pumped CF3Br

Far infrared laser action at 823 and 883 μm is reported for the first time from the optically pumped CF3Br molecule. This molecule exhibits strong absorptions in thePandRbranches of the 9 μm band of the CW CO2laser. Tentative assignments are proposed for the first two transitions observed.     

发射反空空导弹对光电告警系统的需求分析

针对反空空导弹系统对来袭空空导弹的探测需求问题,提出了一种基于空战进程的机载光电告警系统作用距离动态计算方法。该方法首先构造了飞行过程中来袭空空导弹动态红外辐射特征,分析了降雨、云雾及背景干扰在大气传输中的影响,结合典型空战场景,在中红外和远红外波段对光电告警系统的动态探测性能进行了仿真。仿真结果表明,工作在远红外波段的光电告警系统,在空空反导攻击区内能够发现来袭导弹,满足反空空导弹系统的作战需求,进而提高自卫飞机的战场生存力。