共查询到20条相似文献,搜索用时 149 毫秒
1.
密集波分复用激光光源的声光偏频无调制频率锁定 总被引:1,自引:0,他引:1
利用声光调制器(AOM)的偏频特性,以CH4分子吸收线R9支一条强吸收线(λ=1.6378μm)作为参考频率,实现了对外腔式半导体激光器的无调制频率锁定。实验中在100 s内典型的频率起伏小于5.6 MHz,较激光器自由运转时的频率起伏34 MHz有了显著的改善,而误差信号的阿仑(Allan)方差平方根(即稳定度)在平均积分时间为16 s时达到最小值5.75×10-10。该方法实现了基于气体分子吸收线的半导体激光器无调制锁频,并且CH4分子在1.6~1.7μm处有丰富的振转光谱,满足光纤通信中对激光器输出波长的要求,可应用于光纤通信中激光光源的频率锁定。 相似文献
2.
3.
4.
提出利用标准具和光栅光学反馈的方法,实现了对一个7W LD的波长注入锁定.首先利用标准具光学反馈对一个7W LD进行了注入锁定实验.实验中使用一个0.14 mm厚的标准具,其自由光谱范围Δν=714 GHz,条纹精细度F=14.14.由于半导体激光器自由振荡时光谱很宽(达2.4 nm)及标准具厚度的限制,该半导体激光器经标准具反馈注入后被锁定在两个纵模上,波长分别为796.47 nm和798.0 nm,纵模间隔为1.53 nm,与标准具参数一致.但实验中未能获得单纵模运行.在此基础上,又提出了标准具加光栅光学反馈注入的方法.实验中选用1800 线/mm的光栅.当LD驱动电流为3.0 A(自由振荡输出功率为1.39 W)时,获得了单纵模输出.但实验中未能观测到该LD输出远场分布的明显改变.(OC13) 相似文献
5.
6.
7.
8.
9.
10.
11.
Fan Xi-Sheng D. J. E. Knight K. I. Pharaoh 《Journal of Infrared, Millimeter and Terahertz Waves》1984,5(4):421-425
We have measured the frequency of the 187 μm laser emission of methyl fluoride when optically pumped by the 9.17 μm R10 line of the12C18O2 laser, and find it to be f=(1 604 647.7±0.3) MHz. The result is of interest for comparison with recent 9-μm band measurements on methyl fluoride using diode lasers. 相似文献
12.
为实现对军用激光测距机雪崩二极管的有效防护,通过实验的方法测试了VO2薄膜在1064 nm激光辐照下的基本性质,得出了其相变前后透过率与膜厚的关系以及不同厚度VO2薄膜对C30950E雪崩二极管最低饱和入射激光阈值的影响,并给出了拟合公式。实验结果表明,随着膜厚的增加,雪崩二极管的最低饱和入射激光阈值逐渐提高;膜厚为200 nm的VO2薄膜可将雪崩二极管的最低饱和入射激光阈值由5×10-6 W提高到 1.2×10-5 W。由于目前国内针对军用激光测距机雪崩二极管激光防护开展的研究还较少,且大多局限在理论层面、缺乏实验数据支撑,因此本文提供的数据和拟合公式不仅可以进一步验证将VO2薄膜用于军用激光测距机雪崩二极管防护的可行性,而且为进一步开展各型激光测距装备雪崩二极管防护研究提供了数据参考。 相似文献
13.
By adopting a distributed feedback laser (DFBL) centered at 1.654 µm, a near-infrared (NIR) methane (CH4) detection system based on tunable diode laser absorption spectroscopy (TDLAS) is experimentally demonstrated. A laser temperature control as well as wavelength modulation module is developed to control the laser’s operation temperature. The laser’s temperature fluctuation can be limited within the range of ?0.02—0.02 °C, and the laser’s emitting wavelength varies linearly with the temperature and injection current. An open reflective gas sensing probe is realized to double the absorption optical path length from 0.2 m to 0.4 m. Within the detection range of 0—0.01, gas detection experiments were conducted to derive the relation between harmonic amplitude and gas concentration. Based on the Allan deviation at an integral time of 1 s, the limit of detection (LoD) is decided to be 2.952×10-5 with a path length of 0.4 m, indicating a minimum detectable column density of ~1.2×10-5 m. Compared with our previously reported NIR CH4 detection system, this system exhibits some improvement in both optical and electrical structures, including the analogue temperature controller with less software consumption, simple and reliable open reflective sensing probe. 相似文献
14.
X. Y. Chen A. Pedersen O. G. Helles A. D. van Rheenen 《Microelectronics Reliability》2000,40(11):1170
The electrical noise of commercially available laser diodes, an index guided AlGaInP diode lasing at 635 nm (SDL3038-11) and an InGaAlP-multiquantum well diode lasing at 670 nm (SVL71B), has been investigated over a wide current range of six orders of magnitude. After increasing proportionally with current at small currents (10 nA to 10 μA), the 1/f noise tends to saturate with increasing current in the range from 10 to 100 μA. For larger operating currents, the 1/f noise increases again, and with the current proportional to I2. Different noise sources were discovered below the lasing threshold current. The electrical noise at lower currents must be measured to assess the degradation of the active region of the laser diode. 相似文献
15.
G. Carelli N. Ioli A. Moretti G. Moruzzi D. Pereira F. Strumia 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(5):449-471
We have increased the frequency tunability of our CW waveguide CO2 lasers by means of an acoustooptic amplitude modulator, operating at the fixed frequency of 90 MHz. The up-shifted, or down-shifted, laser optical sideband can be generated independently by adjusting the orientation of the modulator. The efficiency is larger than 50%. The frequency tunability of the CO2 laser around each laser line is thus increased by 180 MHz. To demonstrate the possibilities of this method, a source composed of the above modulator and of a CW, 300 MHz tunable waveguide CO2 laser has been used for the search of new large offset FIR laser lines from optically pumped CH3OH and13CH3OH molecules. As a result 15 and 10 new large offset laser lines were discovered respectively. New assignments of some laser lines are also proposed. We have also measured the Stark effect, the offset, and the polarization of other already known lines. In particular a Stark effect frequency tuning of about 1 GHz is demonstrated for a laser line at 208.399 μm. 相似文献
16.
A submillimeter heterodyne spectrometer using continuous wave optically pumped molecular laser as local oscillator and Schottky diode as mixer was developed at Physical Research Laboratory, Ahmedabad (India) for quantitative spectroscopy of polyatomic molecules in laboratory. The experimental details of spectrometer and its application to study of molecular line parameters are presented. In particular line strength, collision line width (self and foreign) of H2S 55,0←54,1 transition1(579.799 GHz) have been measured. Air molecules have been used as foreign (perturbing) molecules taking Earth’s atmosphere into consideration2. 相似文献
17.
P. V. Bulaev V. A. Kapitonov A. V. Lutetskii A. A. Marmalyuk D. B. Nikitin D. N. Nikolaev A. A. Padalitsa N. A. Pikhtin A. D. Bondarev I. D. Zalevskii I. S. Tarasov 《Semiconductors》2002,36(9):1065-1069
A metal-organic chemical vapor deposition (MOCVD) technique is developed for a diode laser heterostructure in a system of InGaAs/GaAs/AlGaAs solid solutions; the optimal sizes and the doping profile of the structure are determined to minimize the internal optical losses. Mesa-strip diode lasers with a threshold density of current J th=150–200 A/cm2, internal optical loss factor αi=1.6–1.9 cm?1, and an internal quantum yield ηi=85–95% were fabricated. In the continuous lasing mode of a diode laser with a 100-µm-wide aperture and a wavelength of 0.98 µm, the optical power output was as high as 6.5 W and was limited by the catastrophic optical degradation of mirrors. The radiation divergence in the plane normal to the p-n junction amounts to θ⊥. The use of wide-gap waveguide layers, which deepens the potential electron well in the active region, is shown to reduce the temperature sensitivity of the InGaAs/GaAs/AlGaAs laser heterostructures in the temperature range from 0 to 70°C. 相似文献
18.
C. Nieswand 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(12):1487-1492
New cascade laser transitions of12CH2F2 at 172.50μm, 208.83μm, 220.44μm, 223.99μm and 250.61μm are reported. A waveguide FIR laser was pumped with a quasi cw12C16O2 laser operating on the 9R32 line. Together with the already known lines at 184.3μm, 196.1μm and 235.9μm, the laser lines can be assigned to rotational transitions in the ν9 vibrational band of12CH2F2 and to refill transitions of the vibrational ground state ν0. 相似文献
19.
D. A. Vinokurov V. A. Kapitonov D. N. Nikolaev A. L. Stankevich A. V. Lyutetskii N. A. Pikhtin S. O. Slipchenko Z. N. Sokolova N. V. Fetisova I. N. Arsent’ev I. S. Tarasov 《Semiconductors》2001,35(11):1324-1328
A MOCVD technology for growth of InGaAs/GaAs/InGaP laser heterostructures on a modified Epiquip VP-50-RP installation was developed. Mesa stripe laser diodes with threshold current density J th=100–200 A/cm2, internal optical loss αi=1.3–1.7 cm?1, and internal quantum efficiency ηi=60–70% have been fabricated. A CW output optical power of 5 W has been obtained for a single 100-µm-wide aperture mesa stripe laser diode emitting at 1.03 µm. It is shown that use of AlGaAs waveguide layers, which increase the conduction band barrier offset, lowers the temperature sensitivity of laser heterostructures within the temperature range 10–80°C. 相似文献
20.
Hui Dai Xizhang Luo Jiayin Qin Xingshi Zheng Yikun Lin 《Journal of Infrared, Millimeter and Terahertz Waves》1998,19(4):621-639
By means of the iteration method, the output power density of the miniature optically pumped NH3 submillimeter wave (SMMW) laser was calculated based on the density matrix equations of a quantum system. Optimization of operating parameters including operating gas pressure, reflection coefficients of input and output meshes of the laser were studied systematically. In the paper, the concepts of the average activated length and the synthetical optimum value were defined, and some rules of the optimization were explained successfully. Experimentally, a cavity NH3 SMMW laser that was composed of a pair of inductive metallic meshes and pumped by TEA-CO2 10R(8) line was used. The experimental results were in good agreement with our theoretical calculations. 相似文献