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1.
Short FIR laser pulses of high repetition rate are obtained by pumping NH3 with the pulses of a passively Q-switched IR laser. The two cascade laser transitions observed show coupled relaxation oscillations. The pulse shapes and delay times are qualitatively in agreement with a four-level rate-equation model.Partially supported by Deutsche ForschungsgemeinschaftOn leave from Korea Standards Research Institute, Dae Deog Dan Ji, P.O. Box 3, Choong Nam, Korea, supported by Korea Science and Engineering Foundation 相似文献
2.
We describe a continuous-wave, low-threshold Tm:YAlO3 (Tm:YAP) laser operating at 1945 nm with incident threshold pump powers in the 10–20 mW range. The z-cavity containing a 2-mm-long Tm:YAP crystal with 4 at.% Tm3+ concentration was end pumped by a continuous-wave Ti:sapphire laser at 795 nm. Tight focusing of the pump and the laser beams enabled low-threshold operation. The power performance of two different cavity configurations with 5-cm radius (R = 5 cm cavity) and 10-cm radius (R = 10 cm cavity) curved mirrors was tested. The best performance was obtained with the R = 10 cm configuration, where, the incident threshold pump power could be lowered to 10 mW after optimizing the polarization direction of the pump beam and by employing double pumping. Theoretical estimation of the threshold power was in good agreement with the experimental observations. The laser could be further tuned from 1842 to 1994 nm. 相似文献
3.
N. Yamabayashi K. Fukai K. Miyazaki K. Fujisawa 《Applied physics. B, Lasers and optics》1981,26(1):33-36
A far-infrared (FIR) NH3 laser was resonantly pumped with a line-tunable infrared (IR) NH3 laser. The number of the observed FIR laser lines amounted to 33. Most of them belonged toaR(J,K) rotation-inversion transition in (0, 1, 0, 0) vibrational state. The line tunability of sealed-off FIR NH3 laser was almost achieved in 90, 115, 150, and 220 m wavelength regions by the selective line tuning of the pumping IR NH3 laser. 相似文献
4.
Characteristic laser efficiency parameters important to Nd3+ doped in various crystalline materials are analyzed. Nd3+: LaF3 was used as a comparative example. Overall laser-crystal performance contributions are emphasized in discussing each parameter. An overview table was compiled containing parameters for comparison of a wide range of crystalline hosts, according to groups of references. 相似文献
5.
M. Jackson E.M. Telles M.D. Allen K.M. Evenson 《Applied physics. B, Lasers and optics》2001,72(7):815-818
A significantly improved far-infrared laser has been used to generate optically pumped laser emissions from 26 to 150 μm for
CD3OH. Using an X–V-pumping geometry, several new laser emissions have been found for CD3OH. In addition, an increase in power, by factors from 10 to 1000, for many of the previously known shorter-wavelength laser
lines, below 100 μm, has been observed. Frequency measurements for several lines have also been performed and have been reported
to a fractional uncertainty up to ±2×10-7, permitting the spectroscopic assignment of the laser transition. One of the frequency-measured lines, 44.256 μm observed
using the 10R34 pump, has confirmed the assignment of the previously reported FIR emission (n,K;J)=(1,7;20)?(0,8;20)A in the
ground vibrational state.
Received: 26 October 2000 / Published online: 7 February 2001 相似文献
6.
The GaCH3 radical has been directly detected by far UV laser mass spectrometry for the first time, as a UV laser photofragment from gaseous trimethylgallium Ga(CH3)3, but not from triethylgallium, Ga(C2H5)3. The relative yield Y() of GaCH3 was measured, at various UV photolysis laser wavelengths =193, 210 and 245 nm, and follows the absorption spectrum of the Ga(CH3)3 precursor molecules. 相似文献
7.
We report on optical pumping experiments in helium-3 using a new broad-band, all fiber laser at 1083 nm. The kinetics of polarization
build-up are compared to the numerical results of an appropriate model. Effects of laser power and bandwidth are discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
B. Oliveira dos Santos C. E. Fellows J. B. de Oliveira e Souza C. A. Massone 《Applied physics. B, Lasers and optics》1986,41(4):241-244
A 3% efficiency, crossed-field type, N2 laser (337.1 nm) has been developed, based on very low inductance circuits (coaxial configuration) and a careful selection of their resonance frequencies. 相似文献
9.
An output of 6 W at 30 kHz was achieved using Tl3AsSe3 as the nonlinear second-harmonic generator. It was pumped with a CO2 laser source at a wavelength of 9.25 m with 20 ns pulses, and the laser beam was focussed to a spot size of 150 m. The focussed spot was scanned to reduce the continuous-wave power loading, and the system could be operated for extended periods of time under these conditions. 相似文献
10.
M. Block O. Rehm P. Seibert G. Werth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(3):461-465
We have measured the lifetime of the metastable 3D
5/2
level in Ca+ using the “quantum jump" technique on a single stored and laser cooled ion in a linear Paul trap. We found a linear dependence
of the measured decay rate on the power of the laser which repumps the ions from the long lived 3D
3/2
level. This can be explained by off-resonant depletion of the 3D
5/2
level. The proper lifetime of this level is obtained by a linear extrapolation of the measured lifetime to zero laser power.
We obtain 1100(18) ms in agreement with theoretical calculations. The observed systematic change of the decay rate resolves
discrepancies between earlier experiments in which this effect had not been considered. Measurements on a linear chain of
10 laser cooled ions showed unexpected frequent coincidences of quantum jumps within our observation time of 20 ms. This indicates
a so far unexplained correlation between the ions in the chain at large distances.
Received 3 March 1999 相似文献
11.
Nilesh J. Vasa Kouki Morishita Husayin Parhat Tatsuo Okada Mitsuo Maeda Osamu Uchino 《Optical Review》1997,4(1):A176-A179
Spectrally pure high-power tunable single-mode operation of a pulsed Ti3+:sapphire laser by a tunable injection-seeding is reported. The injection laser was a cw diode laser pumped, spectrally narrowed
tunable Cr3+:LiSrAlF6 (Cr3+:LiSAF) laser with a grating in the auxiliary cavity. Single-mode tunable operation of a pulsed Ti3+: sapphire ring oscillator was obtained at different wavelengths in the range between 818 nm and 848 nm with a typical linewidth
of 0.006 cm-1. To extend the applicability of this operation to a differential absorption lidar system, the single-mode Ti3+:sapphire oscillator output was amplified and a high energy output of 38 mJ was obtained with the same linewidth. 相似文献
12.
《中国科学:物理学 力学 天文学(英文版)》2015,(11)
Whispering-gallery-mode(WGM) microcavities with high-quality factors and small volumes have attracted intense interests in the past decades because of their potential applications in various research fields such as quantum information, sensing, and optoelectronics. This leads to rapid advance in a variety of processing technologies that can create high-quality WGM micro-cavities. Due to the unique characteristics of femtosecond laser pulses with high peak intensity and ultrashort pulse duration, femtosecond laser shows the ability to carry out ultrahigh precision micromachining of a variety of transparent materials through nonlinear multiphoton absorption and tunneling ionization. This review paper describes the basic principle of femtosecond laser direct writing, and presents an overview of recent progress concerning femtosecond laser three-dimensional(3D) fabrications of optical WGM microcavities, which include the advances in the fabrications of passive and active WGMs microcavities in a variety of materials such as polymer, glass and crystals, as well as in processing the integrated WGM-microcavity device. Lastly, a summary of this dynamic field with a future perspective is given. 相似文献
13.
《中国物理 B》2019,(9)
CsPbBr_3 nanocrystal is used as the saturable absorber(SA) for mode-locking Tm-doped fiber laser in a ring fiber cavity.The modulation depth, saturable intensity, and non-saturable loss of the fabricated SA are 14.1%, 2.5 MW/cm~2,and 5.9%, respectively.In the mode-locking operation, the mode-locked pulse train has a repetition rate of 16.6 MHz with pulse width of 24.2 ps.The laser wavelength is centered at 1992.9 nm with 3-dB spectrum width of 2.5 nm.The maximum output power is 110 mW with slope efficiency of 7.1%.Our experiment shows that CsPbBr_3 nanocrystal can be used as an efficient SA in the 2-μm wavelength region. 相似文献
14.
15.
P. Le Boudec M. Le Flohic P. L. Francois F. Sanchez G. Stephan 《Optical and Quantum Electronics》1993,25(5):359-367
The output intensity of an erbium-doped fibre laser was studied. Experiments were performed with three pumping wavelengths: 514.5 nm, 810 nm and 980 nm. The laser output intensity exhibits three different dynamical behaviours: steady-state, sinusoidal variation or self-pulsing. In particular, in a bad (high-loss) cavity configuration, when the pumping ratio is increased above the lasing threshold the output intensity changes continuously from a steady-state to an infinite train of pulses. We also show that, depending on the cavity configuration, the transient oscillations display different forms. 相似文献
16.
17.
V. S. Letokhov 《Optics & Laser Technology》1977,9(6):263-272
The three basic methods of linear laser spectroscopy are reviewed: absorption, opto-acoustic, and fluorescence spectroscopy. The characteristics of each method and their areas of application are presented and compared. 相似文献
18.
In this letter, a new single three-dimensional (3D) laser projector is proposed. As liquid crystal (LC) can produce two image patterns with orthogonal polarization states at 120 Hz, only one projector is required in this approach for reconstruction of a 3D object. The light source is made up of RGB (red, green, and blue) lasers because laser has lots of advantages such as longer life, higher brightness, and larger color gamut. A novel diffusive media with good polarization-maintaining quality is used as rear projection screen for its high transmission efficiency (-90%) and low reflection efficiency. When laser incidents into the diffusive media, which contains lots of spherical particles with sizes between 2 and 15 μm, laser is scattered randomly and the laser speckle is reduced. A spatial phase mask is also inserted into the optical path to reduce speckle. With these techniques, the speckle contrast is reduced to 0.1 and the quality of image oatterns has been greatlv imoroved. 相似文献
19.
We report what is to our knowledge the first 3-mu;m fiber laser of the 1-W class. 1.7 W of output power and 17.3% slope efficiency (with respect to the launched pump power) at a wavelength of 2.71mum are demonstrated from a double-clad erbium-doped ZBLAN fiber diode pumped at 790 nm. Energy transfer from the Er(3+) lower laser level to a Pr(3+) codopant decreases ground-state bleaching and excited-state absorption, thus avoiding output-power saturation. This result represents more than an order-of-magnitude improvement over previous work of which we are aware. Advantages over current crystal-laser designs include nearly transverse-fundamental-mode operation, reduced thermal effects, and ease of use, e.g., in medical endoscopy. 相似文献
20.
《Infrared physics》1986,26(6):377-380
The intensity and half-widths of the v2 [sP(7,0)] line of ammonia have been measured using an optically pumped CW NH3 laser. The influence of buffer gas is reported. 相似文献