共查询到20条相似文献,搜索用时 31 毫秒
1.
I. K. Kuzmichev P. N. Melezhik A. Ye. Poyedinchuk 《International Journal of Infrared and Millimeter Waves》2006,27(6):857-869
The excitation efficency of the TEM01q
oscillation of an two-mirror hemispherical open resonator (OR) is studied. The resonator is excited by the TE01 wave of a circular waveguide joined in the middle of the OR plane mirror. Given the waveguide optimum size, the TEM01q
mode excitation efficiency reaches 78%. Analysis of the resonant system spectrum in the 4-mm wave region shows that this
waveguide-OR system offers a single mode resonance curve across almost a 10-GHz tuning range. The TEM0110 mode field distribution with and without the circular waveguide in the middle of the OR plane mirror is available due to
the small scatterer method. It is shown that the considered open system is suitable for measuring electromagnetic characteristics
of high-loss substances and metamaterials in the short-wave end of the millimeter (mm) region as well as in the submillimeter
(submm) wave region. 相似文献
2.
Spatial quantum optics and quantum information based on the high order transverse mode are of importance for the super-resolution measurement beyond the quantum noise level. We demonstrated experimentally the transverse plane TEM01 Hermite-Gauss quantum squeezing. The squeezed TEM01 mode is generated in a degenerate optical parametric amplifier with the nonlinear crystal of periodically poled KTiOPO4. The level of 2.2-dB squeezing is measured using a spatial balance homodyne detection system. 相似文献
3.
Y. J. Huang P. Y. Chiang H. C. Liang K. W. Su Y. F. Chen 《Applied physics. B, Lasers and optics》2011,105(2):385-390
We present a compact efficient scheme for generation of high-order Laguerre–Gaussian TEM
p,0 modes in a diode-pumped actively Q-switched Nd:YVO4 laser. The resonator is composed of two plane mirrors with an intracavity concave lens to expand the cavity mode size for
generating a high-power Laguerre–Gaussian TEM5,0 mode. We further confirm that the TEM5,0 mode is noticeably superior to the TEM0,0 mode in the processes of second and third harmonic generations. 相似文献
4.
To obtain single transversal mode oscillation of a laser oscillator a pinhole has to be inserted into the resonator. This causes diffraction losses, comparable with the internal losses of the laser system. For a pulsed Nd-YAG-laser, the total losses and the diffraction losses are determined experimentally as a function of the Fresnel number for TEM00 and TEM01 mode. The agreement between the experimental values and numerical data from diffraction theory is satisfying. 相似文献
5.
The cross-focusing of two co-axial transverse modes of a laser beam viz. TEM00 and TEM01 modes of the same frequency in a non-linear dielectric has been studied. When the TEM00 mode is stronger than the TEM01 mode, both modes focus on the axis. In the opposite case, defocusing occurs at the axis and energy concentrates in a ring. 相似文献
6.
LD side-pumped 41 W high beam quality acousto-optical Q-switched single-rod Nd:YAG laser 总被引:2,自引:0,他引:2
We report a LD side-pumped high beam quality (M
x
2 = 1.20 and M
y
2 = 1.19) acousto-optic (AO) Q-switched single-rod Nd:YAG laser with a TEM00-mode dynamic stable cavity. At the pump power of 600 W, 41 W TEM00-mode 1064 nm laser was achieved with electro-optical conversion efficiency of 7%. The repetition rate and pulse width were
30 kHz and 102 ns, respectively with pulse energy of 1.4 mJ and peak power of 13 kW. Up to 24 W of 532 nm green laser was
generated by external frequency doubling, corresponding to 59% optical conversion efficiency. 相似文献
7.
8.
Hee-Je Kim Myung-Sik Lee Dong-Gil Lee Min-Kyu Son Kyoung-Jun Lee 《Optics and Lasers in Engineering》2009,47(5):558-562
In material processing, a laser system with optimal laser parameters has been considered to be significant. Especially, the laser ablation technology is thought to be very important for fabricating a dye-sensitized solar cell (DSSC) module with good quality. Moreover, the TEM00 mode laser beam is the most dominant factor to decide the incident photon to current conversion efficiency (IPCE) characteristics. In order to get the TEM00 mode, a pin-hole is inserted within a simple pulsed Nd:YAG laser resonator. And the spatial field distribution is measured by using three pin-hole diameters of 1.6, 2.0 and 4.0 mm, respectively. At that moment, each case has the same laser beam energy by adjusting the discharge voltage and pulse per second (pps). From those results, it is known that the pin-hole size of 1.6 mm has the perfect TEM00 mode. In addition, at the charging voltage of 1000 V, 10 pps, the feeding speed of 6.08 mm/s and the overlapping rate (OL) of 62%, the scanning electron microscope (SEM) photograph of fluorine-doped tin oxide (FTO) thin film layers shows the best ablation trace. 相似文献
9.
The degree of spatial coherence between two points separated by 6 mm in a radiation beam is almost unity, when two competing transitions lines which differ below 100 cm-1 oscillate with a TEM00 mode, while it varies greatly when a single line occurs on competing TEM00 and TEM10 modes. 相似文献
10.
Diffraction of symmetrical Laguerre-Gauss TEMp0 beams incident on an opaque disk known as a stop is considered. The near- and far-field patterns are studied. Thanks to zero-field occluding, conversion from TEM10 beam to dark hollow beam can be achieved with better efficiency than from a TEM00 beam. It is shown that the fundamental mode of a laser cavity including a diaphragm and a stop can be TEM00- or TEM10-like in shape depending on their size. This result is interpreted from the new divergence hierarchy, which characterises the diffracted TEMp0 beams emerging from the stop. 相似文献
11.
Farshad Sohbatzadeh Mohsen Rabbani Mahboubeh Ghalandari 《Optics Communications》2012,285(13-14):3191-3194
In this paper, we numerically investigate the relativistic self-focusing of laser beam with LG01 mode in plasmas. An effective potential is introduced to identify the critical power. Numerical methods are employed to solve the governing equations. To verify the numerical procedures, we compare the known analytical solution of the relativistic critical power for TEM00 mode with our numerical method. It is shown that there is a good agreement between our numerical results and the analytical solution. The critical power for relativistic self-focusing of a LG01 laser beam is about 6 times of that for a TEM00 laser beam. 相似文献
12.
K. Liu F. Q. Li Y. Liu D. Cao Y. Bo Q. J. Peng D. F. Cui J. Y. Zhang Z. Y. Xu 《Laser Physics》2012,22(1):95-99
We report on a compact 880-nm diode-directly-pumped passively mode-locked TEM00 Nd:GdVO4 laser at 1341 nm with a semiconductor saturable absorber mirror (SESAM) for the first time. Under the absorbed pump power
of 14.6 W, the maximum output power of 1.27 W was obtained at the repetition rate of 85.3 MHz with the pulse width of 45.3
ps, corresponding to an optical-optical efficiency of 8.8% and the slope efficiency of 33.3%, respectively. The beam quality
factor was measured to be M
2 = 1.18, indicating a TEM00 mode. 相似文献
13.
A. P. Voitovich Yu. V. Loiko A. V. Cherkasov V. V. Nevdakh O. L. Gaiko 《Journal of Applied Spectroscopy》1999,66(5):780-786
The influence of the modal composition (transverse modes of a single longitudinal mode) of the laser radiation on the oscillation
dynamics of a CO2-laser with a saturable absorber in the cavity is investigated. Passive Q-switching in initiation of the fundamental mode
TEM00 and the modes of the first family TEM01 and TEM10 is considered. It is established that in the case of multimode oscillations sequences of single pulses with an irregular
change in their amplitude can be observed. The multimode oscillations obtained are compared with similar single-mode oscillations,
and their special features and differences are discussed.
Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 681–687, September–October, 1999. 相似文献
14.
A novel design of a diode-side-pumped bounce amplifier laser is described that can produce a high-power TEM00 mode and Laguerre–Gaussian (LG) vortex mode operation with high circularity and low astigmatism. The design utilises control
of pump size and bounce angle such that the laser mode experiences substantially circular symmetric gain and spherical thermal
lensing, in a highly compact fundamental mode resonator. In a simple plane–plane Nd:YVO4 laser resonator with no other optical components and total length of just 13.4 cm, highly circularised TEM00 operation is produced at wavelength 1064 nm, with 14.2 W of power and high beam quality M
2<1.05. Stable Q-switched TEM00 operation is demonstrated up to 900 kHz and second harmonic power of 7.2 W at 532 nm is generated with conversion efficiency
up to 64%. Minor modification of the design to exploit the spherical aberration of the thermal lens is shown to allow for
generation of a doughnut-shaped LG vortex mode with average power 16.6 W, maintaining extremely low astigmatism. Q-switched
operation of the vortex mode is accomplished up to 400 kHz. A detailed numerical thermal analysis of the amplifier design
is performed and gives quantitative agreement with experimental results. 相似文献
15.
We demonstrate the stable operation of a 20 W single longitudinal mode TEM00 Nd:YVO4 ring laser at 1064 nm. Unidirectionality of 2500:1 was imposed through retro-reflection of one of the output arms. An additional
extra-cavity pass of the intra-cavity gain medium, in a self-intersecting master oscillator power amplifier setup, is shown
to improve the stable TEM00 operation power from ≈15 to 20.0 W. The spatial quality improvement involves splitting of the gain region into oscillator
and amplifier sections leading to enhanced fundamental mode selection. It is believed that the segregation is, at least in
part, self-organising. 相似文献
16.
Based on the vectorial structure of electromagnetic beam and the method of stationary phase, the analytical TE and TM terms of TM polarized Gaussian beam, the rigorous solution of Maxwell's equations for a confocal resonator, have been presented in the far field. Then in terms of the vectorial structure, TM polarized Gaussian beam is compared with Gaussian TEM00 mode. The TE term is located at the y-axis, and the TM term the x-axis. At the non-paraxial case, the whole beam spot is elliptical, and the long axis is located at the y-axis. Moreover, the whole beam spot of TM polarized Gaussian beam is smaller than that of Gaussian TEM00 mode. At the paraxial case, the whole beam spot is circular, and TM polarized Gaussian beam reduces to be Gaussian TEM00 mode. 相似文献
17.
We observed frequency splitting phenomenon of dual transverse modes (TEM00q and TEM01q) in a Nd:YAG microchip standing wave laser utilizing intracavity stress birefringence effects. Four resonance frequencies (ν00qe, ν00qo, ν01qe, and ν01qo, respectively) were produced and tuned by changing the diametral compression force applied on the laser crystal. The transverse mode frequency spacing for the same longitudinal mode number (Δνtrans) was 1.16 GHz, and the magnitude of frequency splitting (Δν) ranged from 0 MHz to 1.16 GHz. Based on this phenomenon, a four-mode differential standing wave laser, whose signal characteristics were a little like those of a four-mode differential travelling wave laser gyro however with a much larger frequency splitting range, was produced. The theoretical analysis is in good agreement with the experimental results. This phenomenon not only can be used to make lasers with two or more frequency differences, but also can be used to make high-resolution self-sensing laser sensors (e.g. laser force sensors and laser accelerometers). 相似文献
18.
利用激光光束分析仪,实时在线测量了一根He-N2-CO2封离式激光管的横模分布特性,得到了激光模式随放电电流的变化关系.实验表明该激光器在最佳工作电流时,容易形成低阶模运转,但很难获得基模运转,通过改善对称性以及加快冷却水流速可以获得基模运转.通过激光动力学过程分析了模式变化的形成原因,为大功率激光器模式控制与改善提供了一定的理论和实验借鉴.
关键词:
2激光')" href="#">CO2激光
横模
激光模式分析
光束质量 相似文献
19.
High peak power Nd:YAG laser pumped by 600-W diode laser stack 总被引:1,自引:0,他引:1
The Q-switched laser with triangle slab made of Nd:YAG crystal side pumped by 600-W quasi-cw diode laser stack has been designed. The multimode (M2≈2.6) output energy of about 42 mJ was demonstrated in free running mode for110-mJ pump energy. In Q-switch experiments, the KDDP Pockels cell was placed between the slab and rear mirror in plane-plane cavity with output coupler of 84% transmission. The energy of 8 mJ in 2.1-ns pulse duration was obtained for near TEM00 output beam. For passive Q-switching by means of Cr:YAG crystal of 12.6% unsaturated transmission, the energy of 5.1 mJ in 2.5-ns pulse duration was obtained for output beam close to TEM00 mode. 相似文献
20.
A novel end-pumped slab Nd:YVO4 laser with a multifolded quasi-concentric resonator (FCR) is reported. This planar-folded stable resonator matches the sheet-shaped pump volume with the TEM00 mode and yields highly efficiently laser operation with a good beam quality. In a prototype experiment, a 19.55-W output was achieved with a pump power of 45 W, which was single mode in one direction. In addition, the optical-to-optical efficiency reached 43.4%. After introducing a telescope system into the folding plane, a 10.23-W quasi-TEM00 output was obtained, and the overall efficiency was 22.7%. 相似文献