New CW CO2 laser lines: the 9-μm hot band

We have made what we think is the first observation of the oscillation of the 9-μm hot-band lines 01¹1→[11¹ 0,03¹0]_II of CO₂. We have observed 40 lines with a maximum power of 8 W. They will provide a new source of laser radiation for spectroscopy. The set of lines has been positively identified by directly measuring the frequencies of two of the lines with a heterodyne technique using a CO₂ laser standard     

Further investigations of a 2-μm Tm:YVO4 laser

The performance of a Tm:YVO₄ laser has been optimized by varying the thickness of the laser crystal and the reflectivity of the output coupler. This has led to the measurement of a slope efficiency of 48% for the laser output. Formulas describing the saturation of the pump and the upper laser level in the presence of up-conversion loss have been developed. Fitting of the experimental data to the saturation curves calculated using these formulas has yielded an up-conversion rate constant from ³F₄ to ³ H₅ of 2·10^-18 cm³ s^-1      

Frequency stabilization of the sequence-band CO2 laserusing the 4.3-μm fluorescence method

The saturated 1.3-μm fluorescence stabilization method is applied to the 00⁰2-[10⁰1, 02⁰1]_I,II sequence band CO₂ laser transitions. For this purpose, the 4.3-μm fluorescence is observed using an external longitudinal CO₂ absorption cell heated to 300°C. The dependence of the frequency stability upon the gas temperature and pressure in the cell as well as laser parameters have been carried out in absolute frequency scale with the help of a two-channel heterodyne system. Under optimal conditions, the standard deviation of the beat note frequency between sequence band and regular band lasers for 30 s averaging time is less than 20 kHz, and the long-term stability and reproducibility is achieved at about 10 kHz     

序列谱带选支CO_2激光器

本文介绍一种能产生CO_2(00~02—[10~01,02~01]_(Ⅰ,Ⅱ)带激光跃迁,从而使普通封闭选支CO_2激光器输出谱线数目加倍的腔内热吸收池技术及其实验结果。     

13CD3OD optically pumped by a waveguide CO2 laser: new FIR laser lines

A waveguide CO₂ laser of wide tunability was used to pump infrared transitions of the ¹³CD₃OD C-O stretching vibrational mode. The optoacoustic signal associated with the absorbing transitions served as a guide to search for new laser lines. We could observe 36 new far-infrared laser lines ranging from 57 to 1192 μm. All lines were characterized in wavelength, relative polarization, intensity, optimum pressure of operation, and precise offset measurements     

A new three-equation model for the CO2 laser

Three rate equations describing the single-mode CO₂ laser dynamics are derived by applying the theory of linear filters to an improved four-level model. The model is studied in the case of periodic modulations of the losses and compared with the outcome of an experiment, revealing a good agreement     

序列谱线选支CO_2激光器

通常,普通的光栅选支CO_2激光器在(00°1～[10°0,02°0]_(Ⅰ,Ⅱ)带上可获得调谐范围为9～11微米的几十条激光谱线。然而,在CO_2的放电中,在(00°2-[10°1,02°1]_(Ⅰ,Ⅱ)对能级之间还可以实现粒子数反转,这个被称为“序列”带的新的激光谱带与普通选支CO_2激光器输出的“惯常”带具有相类似的增益分布,在9～11微米波长范围内二者谱线数目大致相同,两两对应相互交错,但又十分靠近。但是,在一个普通的选支激光腔内,由于“惯常”带的增益比“序列”带的增益大很多,受竞争效应的影响,一般看不到“序列”带激光谱线。要获得属于“序列”带的     

混合型TEA CO2激光器

本文给出了一种获得单纵模脉冲激光的装置。该激光器由TEA CO2和CWCO2激光器组成,采用内注入,结构简单易注入成功。本实验得到了预期的结果,并提出了进一步改进的方法。     

Zn indiffusion waveguide polarizer on a Y-cut LiNbO3 at1.32-μm wavelength

A polarization-dependent loss measurement of Zn indiffusion (ZI) waveguide on a Y-cut LiNbO₃ substrate is firstly reported. The measured results show that the waveguides support either a single extraordinary polarization or both extraordinary and ordinary polarizations depending on the fabrication process parameters. For the single extraordinary polarization waveguide, the measured propagation loss at 1.32-μm wavelength is 0.9 dB/cm and the best measured polarization extinction ratio is 44 dB at a distance of 1.5 cm from the input end, which are quite good for being a waveguide polarizer. Moreover, the voltage-length product measured for the ZI Mach-Zehnder modulator shows that the substrate electrooptic coefficient is not degraded     

Subnanosecond multi-gigawatt CO2 laser

A semiconductor switching technique has been utilized to produce 30-300 ps variable duration CO₂ laser pulses of 0.5-MW peak power. Eight passes through a 1.2-m long, UV-preionized, 3-atm TE CO₂ amplifier raise the output laser peak power to the 10¹⁰ W level. Sampling the amplifier gain in linear and saturated regimes using CO₂ laser radiation ranging from CW to 30 ps pulse length permits comparison with computer modeling of picosecond CO₂ pulse amplification. The potential for further peak power scaling of picosecond molecular lasers is discussed     

CO_2波导激光器的最佳化

计算了内腔封离型CO_2波导激光器的EH_11波导模的传输和耦合损耗,设计并制造了内腔封离型CO_2波导激光器.器件的最高输出功率为3.57W,单位激活长度和体积的输出功率分别为0.27W/cm、17.3W/cm~3.     

TEA CO_2 10.6微米激光在AgGaS_2晶体中的倍频

研究了AgGaS_2晶体对TEA CO_2 10.6微米激光的倍频特性。晶体厚度4.3毫米时倍频转换效率为0.122％。实测相位匹配角71.5％,调节宽度8°±1°。实验结果与理论计算值非常一致。     

Anomalous gain in an isotopically mixed CO2 laser andapplication to absolute wavelength calibration

Measurements are reported on a grating-tuned CO₂ laser, containing an isotopic mixture of ¹⁶O¹²C¹⁶ O, ¹⁶O¹²C¹⁸O, and ¹⁸O ¹²C¹⁸O. The P₆ and R ₁₄ lines of ¹⁶O¹²C¹⁶O were found to have anomalously high intensities. These anomalies are produced by the near coincidence of the transition frequencies in two distinct isotopes, permitting them to act as a single indistinguishable population. These two lines can be used to identify the rotational quantum numbers in the P and R branch spectra, thereby permitting absolute wavelength calibration to be achieved     

2千瓦横向流动闭合循环CO_2激光器

本文报导了千瓦级横向流动闭合循环 CO_2激光器的组成,着重讨论了无弧光放电电极结构及放电特性。采用多针触发使较大放电电流时的辉光放电稳定性明显提高;主电源直流输出特性及限流电阻选择对放电稳定性及功率输出影响很大。放电区气流速度40米/秒,工作气压46毫米汞柱,激活区长度86厘米,获得2千瓦连续多模输出,电光效率达15%。     

长寿命CO_2激光器

实验证明,要获得长寿命的 CO_2激光器的主要措施有:(1)杜绝慢性漏气;(2)电极材料的选择及氧化处理;(3)减少 CO_2:分子的分解。我们的做法是:激光管不经烘烤,并附加水蒸气,电极材料均经真空除气且充氧氧化,在采用纯银电极、气体组分分别为(1)CO_2-N_2-He-Xe-H_2O;(2)CO_2-CO-He-Xe-H_2O;(3)CO_2-N_2-CO-tte-Xo-H_2O 时,运转寿命分别达(1)10476小时;(2)9185小时(仍在运转);(3)9207小时(仍在运转)。而采用纯镍电极,气体组分为 CO_2-N_2-He-Xe-H_2O,运转寿命达1644小时。     

声光Q开关波导CO2激光器

用Ge单晶作为声光介质首次研制出声光Q开关波导CO2激光器,Q开关激光脉冲重复频率从0Hz到200kHz任意可调。文中对这种Q开关激光器的性能作了介绍。     

无He高速流动CO_2激光器的研究

用一个开环流动装置研究了无He混合气的放电CO_2激光输出特性,获得1400W的输出,电光效率～5％,并建立了流动条件下的分子动力学模型,分析计算了小讯号增益、气压、密度、流速、温度等参数沿流场的分布。     

High-power two-dimensional waveguide CO2 laser arrays

A two-dimensional, 39 element array of waveguide carbon dioxide lasers has produced a total CW laser power output of 750 W, using RF excitation of a compact, close packed assembly. Thermal effects associated with close-packing in the array are evaluated in terms of discharge wall temperature rise and cavity mirror distortion. The array elements are shown to have a 30% power derating relative to a single isolated laser channel, caused mainly by internal temperature rise. Mirror distortion and waveguide constructional errors do not degrade the beam quality of the array emission, which matches the theoretical value. However mirror distortion is shown to be responsible for a large spread in laser frequency between channels in the array. Based on the results, prospects are good for the construction of larger, multikilowatt incoherent arrays     

TEA序列带CO2激光器的实验研究

Using an in－cavity hot CO₂ cell that is shorter than a TEA CO₂ discharge length,conversion characteristic of a TEA CO₂ laser operating on sequence bands is studed.Choosing proper operation conditions,output can be attained on more than 40 sequence lines and the output energy per pulse exceeds 1J on more than 10 lines.     

CO2激光参量上转换的研究

本文首次报道了CO2激光在AgGaS2晶体中上转换成近红外辐射的研究结果。用SPD-052雪崩光电二极管探测,获得的等效噪声功率(NEP)～3.8×10-8W,探测灵敏度(Dλ#)～1010cmHz1/2W-1。Ⅱ类非共线相位匹配的功率转换效率估计为10%。