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1.
A Teller–Landau six-temperature model describing the dynamic emission of single-mode TEA CO2 laser has been adapted. This model has been also used to describe the mechanism of obtaining relatively high-power output pulses from hybrid TE-TEA or CW-TEA CO2 laser consisting of high- and low-pressure sections. The suggested mathematical model allows to investigate the mechanism which limits the TEA oscillation to single longitudinal mode (SLM) due to the narrow gain bandwidth of low-pressure section, and also to study the effect of the laser input parameters on the smooth output laser pulse parameters. In addition, numerical solutions of non-linear rate equation system of the suggested model are quantitatively discussed. The solutions describe the radiation field intensity, the population inversion, and the energy transfer processes. The calculated values of maximum peak power, total energy in pulse, pulse width, etc. are in a very good agreement with the observed experimental values. 相似文献
2.
Yuanhu Wang Yanchen Qu Weijiang Zhao Chenghong Jiao Zhiqiang Liang Deming Ren 《Optics Communications》2009,282(8):1615-1618
An effective single-longitudinal mode (SLM) pulse TEA CO2 laser operation was demonstrated using a Michelson’s type resonator with a tilting Fabry-Perot etalon. A modified numerical model of the interference resonator was investigated for designing the laser. The experimentally measured values were found to have good agreement with the numerical model. A pulse width of about 90 ns and the maximum pulse energy of about 300 mJ were achieved at 10.59 μm in SLM and TEM00 mode. The reliability of producing SLM pulses was 100% and there was no damage on the etalon. By turning the interference resonator, the SLM output was tuned 44 lines of the CO2 spectrum. 相似文献
3.
Y. Wang Y. Qu W. Zhao D. Ren C. Jiao Z. Liang 《Applied physics. B, Lasers and optics》2010,98(4):743-750
The performance of a simple resonator that couples a reflective multipass interferometer cavity and a Fabry-Pérot etalon to
obtain high efficiency tunable single-longitudinal mode (SLM) oscillation in a TEA CO2 laser is reported. A numerical model of the resonator was explained to predict the mode behavior of the laser as well as
to optimize the resonator to achieve SLM operation, and the predicted mode characters are experimentally verified. 相似文献
4.
Y.H. Wang Y.C. Qu W.J. Zhao D.M. Ren X.Y. Hu 《Applied physics. B, Lasers and optics》2008,92(2):237-241
We present a single longitudinal mode (SLM) TEA CO2 laser oscillation by using a three-mirror resonator with a Fabry–Pérot etalon. The etalon was inserted in the optical path
taken out from the main resonator of the CO2 laser for protecting the etalon from damage on the surface. A modified numerical model of the three- mirror resonator was
investigated for design the laser. SLM pulse from the TEA CO2 laser was achieved, and the experimentally measure values were found to have good agreement with the numerical model. The
maximum pulse energy of reliable SLM emission is obtained in excess of 200 mJ at 9.57 μm. The reliability of producing SLM
pulses was higher than 90%, and there was no damage on the etalon
PACS 42.55.Lt; 42.60.Fc 相似文献
5.
Gautam C. Patil Pallavi Raote J. Padma Nilaya D.J. Biswas 《Optics Communications》2009,282(20):4100-4102
The enhanced efficiency, almost by a factor of 9, of preionisation when the laser is self-switched by a mutually coupled parallel spark preioniser as against its conventional operation with inductively ballasted preioniser, has been demonstrated in the operation of a TEA CO2 laser. The increased preionisation peak current due to the near ballast free operation of the mutually coupled parallel spark channels is shown to be responsible for the observed behavior. 相似文献
6.
7.
Simple possibility of single tunable picosecond pulse generation in a conventional inexpensive distributed feedback dye laser (DFDL) is demonstrated. It is shown that when a TEA N2-laser is used for pumping no diffraction grating is necessary in the DFDL optical scheme for operation in the picosecond regime. Hence wide-range spectral tuning from 357 to 665 nm was easily achieved. When pumped with a 0.6 ns 40 kW pulse of the TEA N2-laser the DFDL generated pulses as short as 7 ps with time-bandwidth product better than 0.6 and peak power ? 10 kW. At a repetition rate of 50 pps the shot-to-shot energy stability of a single picosecond pulse was ±18% at ±7% stability of the TEA N2-laser. 相似文献
8.
Li D. J. Yang G. L. Chen F. Xie J. J. Zhang L. M. Guo J. Shao C. L. Peng Z. Q. Lu Q. P. 《Laser Physics》2012,22(5):937-940
Stimulated rotational Raman scattering (SRRS) at multiwavelength pumped by TEA CO2 laser was demonstrated in this paper. Raman mediums were cooled by liquid-N2 and a multiple-pass cell (MPC) with 25 passes was designed and used. When the para-H2 was pumped by single-longitudinal-mode
(SLM) circular polarized TEA CO2 laser on 10P(20), 9P(20), and 10R(20), 50 mJ 16.95 μm, 350 mJ 14.44 μm, and 536 mJ 16.9 μm radiations were obtained, corresponding
to energy conversion efficiency of 1.2, 11.7, and 13.4%, respectively. When the ortho-D2 was pumped by CO2 laser on 10R(18), 108 mJ 12.57 μm Raman laser was obtained with energy conversion efficiency of 2.9%. 相似文献
9.
N. R. Heckenberg B. J. Renton S. T. Shanahan W. Wright 《Applied physics. B, Lasers and optics》1982,29(2):67-72
The effect of injecting radiation from a cw waveguide CO2 laser into a TEA laser through a hole in one mirror of its unstable resonator has been studied experimentally. High-power single longitudinal mode operation of the TEA laser is achieved over a wide but finite range of injection frequencies, the frequency of the single-mode pulse being that of the TEA laser cavity mode lying closest to the injected frequency. Although a simple theoretical model shows good qualitative agreement with observations it underestimates the range of injection frequencies which result in single-mode pulses unless a fast chirping of the cavity mode frequency is postulated. 相似文献
10.
Operation of a CH3F laser at 496μ has been obtained in a hemispherical optical cavity pumped by up to 42 J of 9.55μ CO2 TEA laser radiation. Highly modulated 1μ pulses delivering 6 mJ at peak powers greater than 10 kW have been recorded. 相似文献
11.
Noncollinear four photon mixing of two TEA CO2 laser beams in germanium at room temperature has been used to obtain phase-matched generation of step tunable radiation in the 8.7 μm region which is of interest for the uranium isotope separation. Using an 8.3 cm long crystal of germanium, peak output power of ≈10kW (corresponding to 1 mJ per pulse) was obtained at 8.7 μm with 3 MW peak input power from each of the two CO2 lasers operating at 9.6 μm and 10.6 μm. 相似文献
12.
Stable single longitudinal mode erbium-doped silica fiber laser based on asymmetric linear three-cavity structure
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We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber (EDF) to form asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio (OSNR) of about 60 dB is verified experimentally. In laboratory condition, the performance of power fluctuation of less than 0.05 dB observed from the power meter for 6 h and wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer (OSA) for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser. 相似文献
13.
Stable single longitudinal mode erbium-doped silica fiber laser based on an asymmetric linear three-cavity structure
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We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber (EDF) to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio (OSNR) of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer (OSA) for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser. 相似文献
14.
Aniruddha Kumar J. Padma Nilaya M.B. Sai Prasad P. Raote D.J. Biswas 《Optics & Laser Technology》2008,40(8):1068-1071
The operation of a helium-free TEA CO2 laser is found to depend more sensitively on the delay between the pre and main discharges as against its conventional operation. Results pertaining to the optimum delay and the temporal shape of the emission are presented for the operation of the helium-free laser with both sequential and parallel spark-type preionisers. 相似文献
15.
An all-solid-state single-longitudinal-mode (SLM) laser at 500.8 nm with 830 mW output power has been demonstrated for the
first time. By using a new resonator for doubly resonant, Nd:GdVO4 and Nd:YAG were pumped by two laser diode arrays coupled by optical fiber, respectively. In the two sub-cavities, SLM wavelengths
of 1064 and 946 nm were induced by using the twisted-mode technique and then mixed into SLM 500.8 nm laser with sum-frequency
technology. The SLM 500.8 nm laser output of 830 mW was obtained at the incident pump power of 20 W for Nd:GdVO4 and 23 W for Nd:YAG. The experimental results showed that the intracavity sum-frequency mixing by twisted-mode technique
is an effective method for SLM 500.8 nm laser. 相似文献
16.
In order to obtain short tail-free output laser pulses from a TEA CO2 laser, parametric study of the laser operation with CO2/H2 and CO2/He binary gas mixtures containing high CO2 concentrations was carried out. A small scale UV preionized short delay time TEA CO2 laser was employed. In terms of the maximum extractable output pulse energy and power, the more conventional CO2/He gas mixture was found to be inferior in comparison with the CO2/H2 mixture proposed here. 相似文献
17.
M.C. Gower 《Optics Communications》1974,12(3):246-247
Using a laser interferometric technique changes in the refractive index at 633 nm of the pulsed discharge of a TEA CO2-N2-He laser amplifier have been observed. Heating of the medium by the discharge reduces the density and hence the refractive index of the gas. The peak temperature was found to be reached between 0.15 and 0.25 msec after the current pulse. For values of voltage and pressure typical for 10.6 μm laser operation a temperature of ~430 K was measured. The system returned to thermal equilibrium after 23 and 27 msec. Thermal diffusion time calculations indicate that the heating is confined to within 3 to 4 mm of the central axis. 相似文献
18.
We present a theoretical model to study the effect of the pump spectrum and axial mode separation on the single longitudinal mode operation of a laser with a homogeneously broadened semi-monolithic gain medium of short absorption depth. The characterizing parameter is the ratio of the pump power up to which single longitudinal mode is possible to the pump power at the lasing threshold and is denoted by rmax. A numerical study using a Gaussian-shaped pump spectrum reveals that, for a small value of the axial mode separation and for a crystal with short absorption depth at the pump wavelength, the value of rmax reduces significantly with increase in the FWHM of the pump spectrum and thereby results in degradation of the single longitudinal mode performance of the system. However, for large value of the axial mode separation, the SLM performance was found to be nearly independent of the variations in the spectral bandwidth of the pump beam, location of its peak emission wavelength and its polarization. 相似文献
19.
It is found that a premature initiation of the gain switch in a TEA CO2 laser oscillator is produced by optical interaction from an adjacent amplifier with the consequence that the peak oscillator power is reduced by a factor of three. 相似文献
20.
The operation of a volume excited TEA CO2 laser using an unstable resonator configuration is described. Considerable improvement over conventional single mode operation is achieved. The theoretical and experimental far field patterns are compared. 相似文献