共查询到20条相似文献,搜索用时 156 毫秒
1.
Gang Zhang Shengzhi Zhao Kejian Yang Guiqiu Li Dechun Li Kang Cheng Chao Han Bin Zhao Yonggang Wang 《Optics & Laser Technology》2012,44(4):794-799
By using both the single-walled carbon nanotube saturable absorber (SWCNT-SA) and the electro-optic (EO) modulator, the stably doubly Q-switched and mode-locked (QML) operation of Nd:Gd0.3Lu0.33Y0.37VO4 laser has been demonstrated. The QML laser characteristics such as the pulse width, single-pulse energy, etc., have been measured for different modulation frequencies of the EO modulator (fe) and reflectivity (R) of output coupler. In comparison with the solely passively QML laser with SWCNT-SA, the experimental results show that the doubly QML laser can generate more stable and shorter pulses with higher pulse energy. At 9.24 W pump power, fe=1 kHz and R=93.5%, the doubly QML laser has compressed the Q-switched envelope pulse width 88% and improved the mode-locked pulsed energy 55 times. 相似文献
2.
K. Cheng S.Z. Zhao K.J. Yang G.Q. Li D.C. Li G Zhang B. Zhao Y.G. Wang 《Optics & Laser Technology》2012,44(4):903-906
By simultaneously using an electro-optic (EO) modulator and a single-walled carbon nanotube saturable absorber (SWCNT-SA) in the cavity, a diode-pumped doubly Q-switched Nd:Lu0.33Y0.37Gd0.3VO4 (Nd:LuYGdVO4) laser is demonstrated. At the incident pump power 11.43 W and f=2 kHz, the minimum pulse width 17.6 ns and the maximum pulse peak power 19,886 W can be obtained. The experimental results show that this doubly Q-switched Nd:LuYGdVO4 laser can generate shorter pulse width and higher peak power compared to the singly Q-switched Nd:LuYGdVO4 laser with only EO or SWCNT-SA. 相似文献
3.
Yan Zhang Dechun Li Kejian Yang Guiqiu Li Gang Zhang Kang Cheng 《Optics Communications》2010,283(24):5121-5125
By using both acousto-optic (AO) modulator and GaAs saturable absorber, a diode-pumped doubly Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser is presented. The average output power and the pulse width of the Q-switched envelope have been measured. The Q-switch pulse energy of the doubly QML laser are higher than that only with GaAs. The stability of the QML laser with the dual-loss-modulation is significantly improved if compared to that only with GaAs.The experimental results show that the doubly QML YVO4/Nd:YVO4 laser has nearly 80% modulation depth and deeper than that of the singly passively QML pulse. The doubly Q-switched mode-locked pulse inside the Q-switched envelope has a repetition rate of 111 MHz and its pulse width is estimated to be about 700 ps. By using a hyperbolic secant square function and considering the Gaussian distribution of the intracavity photon density, the coupled equations for diode-pumped dual-loss-modulated QML laser is given and the numerical solutions of the equations are in good agreement with the experimental results. 相似文献
4.
Gang Zhang Dechun Li Kejian Yang Guiqiu Li Kang Cheng Yan Zhang 《Optics Communications》2011,284(7):1982-1987
By considering the influence of the acousto-optic (AO) modulator and the nonlinear loss due to harmonic conversion in the intra-cavity frequency-doubling laser, a developed rate equation model for diode-pumped dual-loss-modulated Q-switched and mode-locked (QML) Nd:LuVO4/KTP green laser with acousto-optic (AO) modulator and Cr4+:YAG saturable absorber is presented. With this developed model, the pulse width, single-pulse energy and the other dual-loss-modulated QML green laser characteristics are numerically simulated. The simulation results show that the turnoff time is of great importance for the pulse energy and pulse width of the Q-switched pulse. A diode-pumped dual-loss-modulated QML Nd:LuVO4/KTP laser is constructed to successfully demonstrate the numerical simulation application. 相似文献
5.
A diode-pumped dual-loss-modulated Q-switched and mode-locked (QML) Nd:Lu0.15Y0.85VO4 laser at 1.34 μm with single-walled carbon nanotube saturable absorber (SWCNT-SA) and acousto-optic (AO) modulator is demonstrated.
The modulation depth of the dual-loss-modulated QML laser reaches 90%, being deeper than 75% that obtained by the single passively
QML laser. The stability of the hybrid QML laser is significantly improved if compared to that only with SWCNT-SA. The Q-switched
pulse energy and the Q-switched pulse width of the QML laser with the dual-loss-modulation are 487 and 27% of those only with
SWCNT-SA, respectively. 相似文献
6.
By using a-cut Nd:Lu0.15Y0.85VO4 mixed crystal as laser gain medium, a diode-pumped passively Q-switched and mode-locked (QML) laser with a GaAs saturable
absorber in a Z-type folded cavity is demonstrated for the first time. The Q-switched mode-locked laser pulses with about 90% modulation
depth are obtained as long as the pump power reached the oscillation threshold. The repetition rate of the passively Q-switched
pulse envelope ranges from 50 to 186 kHz as the pump power increases from 0.915 to 6.520 W. Under an incident pump power of
6.52 W, the QML pulses with the largest average output power of 694 mW, the shortest pulse width of 200 ns and the highest
pulse energy of 3.73 μJ are obtained. The mode-locked pulse width inside the Q-switched envelope is estimated to be about
275 ps. The experimental results show that Nd:Lu0.15Y0.85VO4 is a promising mixed crystal for QML laser. 相似文献
7.
H. J. Zhang S. Z. Zhao K. J. Yang G. Q. Li D. C. Li J. Zhao 《Applied physics. B, Lasers and optics》2013,112(2):185-192
Using electro-optic (EO) modulator and GaAs saturable absorber, a diode-pumped doubly Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser at 1.06 μm is realized. The experimental results show that the number of the mode-locking pulses underneath the Q-switched envelope decreased with increasing pump power. With an output coupling of 6.5 %, the single mode-locking pulse underneath the Q-switched envelope with 1 kHz repetition rate was obtained when the pump power exceeded 4.65 W. At a pump power of 8.25 W for an output coupling of 10 %, a stable mode-locking pulse train at a repetition rate of 1 kHz was achieved with pulse energy as high as 582 μJ and pulse duration of about 580 ps, corresponding to a peak power of 1 MW. Using a hyperbolic secant square function and considering the Gaussian distribution of the intracavity photon density, the coupled rate equations for diode-pumped doubly QML YVO4/Nd:YVO4 laser are given and the numerical solutions of the equations are basically in accordance with the experimental results. 相似文献
8.
G. Zhang S. Z. Zhao D. C. Li K. J. Yang G. Q. Li K. Cheng Y. Zhang B. Zhao 《Laser Physics》2011,21(9):1539-1544
A diode-pumped dual-loss-modulated Q-switched and mode-locked (QML) Nd:Lu0.15Y0.85VO4 laser with acousto-optic (AO) modulator and Cr4+:YAG saturable absorber is presented. The stable QML laser pulse with high peak power and complete modulation depth has been
obtained. The QML laser characteristics such as the pulse width, single-pulse energy etc. have been measured for different
small-signal transmissions (T
0) of Cr4+:YAG, different reflectivity (R) of output coupler and modulation frequencies of the AO modulator (f
p
). The results show that the pulse energy increases with decreasing f
p
and increasing T
0, while the pulse width decreases with decreasing f
p
and increasing T
0. At f
p
= 10 kHz, R = 90%, and T
0 = 91%, the highest pulse energy and peak power of mode-locked pulses is obtained. 相似文献
9.
G. Zhang S. Zhao Y. Li G. Li D. Li K. Yang T. Li K. Cheng H. Ge Y. Zhang Z. Yu 《Laser Physics》2010,20(6):1307-1311
A diode-pumped Q-switched and mode-locked (QML) Nd:LuVO4/KTP green laser with acousto-optic modulator (AOM) and Cr4+:YAG saturable absorber is presented. By inserting an AOM into the laser cavity, the stability of the QML green laser pulse with AO and Cr4+:YAG is improved, the modulation depth is increased and the pulse width of Q-switched pulse envelope is significantly compressed in comparison with that of the singly passively QML green laser with Cr4+:YAG. The experimental results show that the peak power of the doubly QML green laser pulse is much higher than that of the singly passively QML green laser pulse. 相似文献
10.
We report the first demonstration, to our knowledge, of passive Q-switched mode-locking in a Tm3+:YAP laser, operating in the 2 μm broadly spectral region formed with a compact Z-flod cavity. A transmission-type single-walled carbon nanotube saturable absorber (SWCNT–SA) is used for the initiation of the pulse generation. The repetition rate of the Q-switched envelope was 60 kHz at the pump power of 8.6 W. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of ~92 MHz. A maximum average output power of 761 mW was obtained. The dependence of the operational parameters on the pump power was also investigated experimentally. 相似文献
11.
Chao Han Shengzhi Zhao Dechun Li Guiqiu Li Kejian Yang Gang Zhang Kang Cheng 《Optics & Laser Technology》2012,44(3):696-700
By considering the single-photon absorption (SPA) and two-photon absorption (TPA) processes in the GaAs saturable absorber, the coupled rate equations for a diode-pumped passively Q-switched and mode-locked (QML) laser with GaAs coupler under Gaussian approximation are given. The key parameters of an optimally coupled passively QML laser can be obtained by numerically solving these equations. These key parameters include the parameters of the gain medium, the saturable absorber and the resonator, which can maximize the pulse energy of singly Q-switched envelope. Sample calculations for a diode-pumped passively Q-switched mode-locked c-cut Nd:GdVO4 laser with a GaAs saturable absorber are presented to demonstrate the optimal method applicable. 相似文献
12.
A passively Q-switched a-cut Nd:GdVO4 self-Raman solid-state laser with Cr:YAG saturable absorber was firstly demonstrated. The first Stokes at 1173 nm was successfully obtained. At the maximum incident pump power, the pulse width was about 1.8 ns and the repetition rate was 27.5 kHz. 586.5 nm yellow laser output was also realized by use of an LBO frequency doubling crystal. 相似文献
13.
A diode-pumped passively Q-switched mode-locked (QML) intracavity frequency-doubled Nd:GdVO4/KTP green laser with a semiconductor saturable absorber is presented. Nearly 100% modulation depth for the mode-locked green pulses can be achieved at any pump power over 1.92 W. The width of the mode-locked green pulse was estimated to be about 150 ps. The mode-locked pulse interval within the Q-switched envelope of 320 ns and the repetition rate of 97.5 kHz were obtained, at an incident pump power of 4.4 W. The repetition rate of the mode-locked green pulses inside the Q-switched envelope was 140 MHz. 相似文献
14.
We have demonstrated an efficient and compact passively Q-switched and mode-locked (QML) 1064 nm Nd:YVO4 laser by using a low temperature grown GaAs (LT-GaAs) saturable absorber as well as an output coupler. Stable QML with envelope duration as short as 10 ns and Q-switched repetition rate of 36 kHz was obtained. It is the shortest envelope duration as far as we know, and it is so short that it can be used as Q-switching pulses directly. At 6.9 W of the incident pump power, average output power of 1.24 W was achieved and the corresponding peak power and energy of a single Q-switched pulse were 3.44 kW and 34.4 μJ, respectively. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of 780 MHz. 相似文献
15.
By using double-mixed crystal Nd:Lu0.15Y0.85VO4 as laser medium, a diode-pumped doubly Q-switched and mode-locked (QML) Nd:Lu0.15Y0.85VO4 laser with acousto-optic (AO) modulator and central semiconductor saturable absorption mirror (SESAM) is realized for the
first time. The Q-switched envelope modulation depth is nearly 100%.The average output power and the pulse width of the Q-switched
envelope etc. for different AO modulator repetition rates have been measured. The experimental result show that Nd:Lu0.15Y0.85VO4 crystal is an excellent laser medium for doubly QML lasers. 相似文献
16.
For Nd:LaxY1−xVO4 (x = 0.11) crystal, the 4F3/2 → 4I13/2 transition property was investigated for the first time. The fluorescence peak of Nd:La0.11Y0.89VO4 crystal exhibited obvious inhomogeneous broadening comparing with that of Nd:YVO4 crystal. With laser diode array as pump source, 1.34 μm continuous-wave (CW) and active Q-switched laser operations based on 4F3/2 → 4I13/2 transition were realized. For CW laser operation, the maximum output power of 2.47, 2.13 W is obtained with slope efficiencies of 29.4%, 27.6%, and optical to optical conversion efficiency of 26.2%, 24.7%, respectively for a, c cut crystal samples. For acousto-optic (AO) Q-switched laser operation, the shortest pulse width, highest peak power and maximum pulse energy came from the a-cut sample, which were 13 ns, 2.69 kW and 35 μJ, respectively. 相似文献
17.
P. K. Datta Chandrajit Basu S. Mukhopadhyay S. K. Das G. K. Samanta Antonio Agnesi 《Pramana》2004,63(5):1003-1010
A non-linear mirror consisting of a lithium triborate crystal and a dichroic output coupler are used to mode-lock (passively)
an Nd : YVO4 laser, pumped by a diode laser array. The laser can operate both in cw mode-locked and simultaneously Q-switched and mode-locked
(QML) regime. The peak power of the laser while operating in QML regime is much higher but pulses suffers from poor amplitude
stability. The incorporation of an acousto-optic modulator as an active Q-switch enhances the stability of the QML pulse envelope.
The second-order non-linearity of powdered crystalline urea is conclusively measured with respect to KDP while the laser is
operating in passively Q-switched and passively mode-locked regime as well as in actively Q-switched and passively mode-locked
regime. 相似文献
18.
Output performance of a continuous-wave (CW) laser diode end-pumped passively Q-switched Tm,Ho:YLF laser is demonstrated with a Cr:ZnS crystal as the saturable absorber. We particularly investigate the influence of saturable absorber's position in the resonator when the Cr:ZnS crystal is placed close to and far from the laser beam waist. We compare the experimental results at the two different positions, and find that the laser shows unusual output characteristics when the Cr:ZnS saturable absorber is placed close to the beam waist. The pulse width and the pulse energy almost keep constant, measured about 1.25 μs and 4 μJ respectively, when the pump power is changed in the range of 1–1.9 W. Moreover, the pulse repetition frequency can be tuned between 1.3 kHz and 2.6 kHz by changing the pump power. The output wavelength of the passively Q-switched laser shifts to 2053 nm from 2067 nm in CW operation. 相似文献
19.
Cheng-Cheng Liu Yong-Gang Wang Jie Liu Li-He Zheng Liang-Bi Su Jun Xu 《Optics Communications》2012,285(6):1352-1355
Single-walled carbon nanotube (SWCNT) absorber fabricated by vertical evaporation is used in passively mode-locked Yb3 +:Sc2SiO5 (Yb:SSO) ultrafast laser for the first time. The performance of Yb:SSO ultrafast laser with pulse width as short as 880 fs is studied and the average output power is 712 mW. To our knowledge, this is the highest output power of femtosecond lasers with SWCNT-SAs reported. In addition, we firstly demonstrate a passively mode-locked picosecond Yb:SSO laser without inserting any dispersion compensation device. The pulses width is as short as 5.4 ps and the output power is 940 mW. 相似文献
20.
In this letter, a diode-pumped continuous-wave and passively Q-switched 1.06 μm laser with a novel composite YVO4/Nd:GdVO4 crystal was demonstrated for the first time. Theoretical calculations showed that the temperature distribution in YVO4/Nd:GdVO4 crystal was lower than that in GdVO4/Nd:GdVO4 and Nd:GdVO4 crystals under the same conditions. After optimizing the mode matching degree, a CW output power of 5.6 W of YVO4/Nd:GdVO4 laser was obtained at the incident pump power of 12 W when the output coupler with transmission of 30% was employed. Using Cr4 +:YAG crystals with initial transmission (T0) of 80% and 90% as saturable absorbers, the pulsed YVO4/Nd:GdVO4 laser characteristics were investigated. At the incident pump power of 12 W, the maximum average output power of 2.76 W and the maximum repetition rate of 189 kHz was achieved when T0 = 90% Cr4 +:YAG was used. The shortest pulse width was 28.1 ns when the initial transmission of the used Cr4 +:YAG was 80%. 相似文献