共查询到20条相似文献,搜索用时 31 毫秒
1.
We demonstrate the generation of phase-coherent frequency combs in the vacuum utraviolet spectral region. The output from a mode-locked laser is stabilized to a femtosecond enhancement cavity with a gas jet at the intracavity focus. The resulting high-peak power of the intracavity pulse enables efficient high-harmonic generation by utilizing the full repetition rate of the laser. Optical-heterodyne-based measurements reveal that the coherent frequency comb structure of the original laser is fully preserved in the high-harmonic generation process. These results open the door for precision frequency metrology at extreme ultraviolet wavelengths and permit the efficient generation of phase-coherent high-order harmonics using only a standard laser oscillator without active amplification of single pulses. 相似文献
2.
We experimentally demonstrate the amplification of picosecond pulses at high repetition rates through the coherent addition of successive pulses of a mode-locked pulse train in a high-finesse optical cavity equipped with cavity dumping. Amplification greater than 30 times is obtained at a repetition rate of 253 kHz, boosting the 5.3-nJ pulses from a commercial mode-locked picosecond Ti:sapphire laser to pulse energies of more than 150 nJ. 相似文献
3.
The frequency of an acousto-optic mode-locker is detuned from the fundamental resonance frequency of the cavity resulting in undamped oscillations of the laser pulse energy. The envelope of the mode-locked pulse train consists of spikes 10 μs wide with a repetition time of 46 μs. The energy of the mode-locked pulses in a spike is increased by up to a factor of 50 compared to a cw-mode-locked pulse. The pulse width can be as short as 700 ps. 相似文献
4.
A long train of actively mode-locked pulses is obtained from a negative feedback controlled Nd:YAG laser. The 70s pulse train contains up to 0.1 J energy and the duration of the picosecond pulses is 120 ps. The laser is operated at a repetition rate of 20 Hz. ActiveQ-control of the cavity generates a short pulse train of duration 50 to 70 ns. An excellent peak-to-background intensity ratio of the correlation function for the picosecond pulses in the train of 5×103 is reported. 相似文献
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6.
The feasibility of ultrahigh-resolution coherence spectroscopy with a train of picosecond light pulses from a synchronously pumped mode-locked and cavity-dumped dye laser is demonstrated. Narrow resonances of periodic pulse excitation are observed whenever the pulse repetition rate of the laser of a higher harmonic coincides with the frequency splitting of coherently excited levels. The zero-field hyperfine splitting of the Na-ground state (1771.6 MHz) could be measured in the 2100th order of the excitation rate with a resonance halfwidth of 800 Hz. 相似文献
7.
H. Ge S. Zhao Y. Li G. Li D. Li K. Yang M. Li G. Zhang K. Cheng Z. Yu 《Laser Physics》2009,19(6):1226-1229
We present a compact passively Q-switched mode-locked Nd:LuVO4 laser run in a Z-type folded cavity with semiconductor saturable absorber mirror (SESAM). The repetition rates of the passively Q-switched pulse envelope ranges from 22.99 to 141.18 kHz as the pump power increased from 2.372 to 8.960 W. The repetition rates of mode-locked laser pulses in the Q-switched pulse envelope has 111 MHz determined by the cavity length and the mode-locked pulse duration is evaluated to be 257 ps. An average output power of 823.5 mW is achieved at the pump power of 8.96 W, corresponding to an optical conversion efficiency of 9.2%. 相似文献
8.
Xie GQ Tang DY Luo H Zhang HJ Yu HH Wang JY Tao XT Jiang MH Qian LJ 《Optics letters》2008,33(16):1872-1874
We have experimentally demonstrated a dual-wavelength synchronously mode-locked Nd:CNGG laser based on the semiconductor saturable absorber mirror technique. Mode locking was achieved simultaneously on two gain bands of the crystal that have a central wavelength separation of 2.4 nm. The fundamental mode-locked pulse train has a repetition rate of 88 MHz and pulse duration of 5 ps, with an average output power of approximately 90 mW. Autocorrelation measurements show that each of the synchronously mode-locked pulses consists of a train of quasi-periodic beat pulses with a 660 fs pulse width and a 0.63 THz repetition rate. 相似文献
9.
We have experimentally achieved the 8.3-ps ultra-short pulse at 10 GHz repetition rate with the time jitter as low as 590
fs in an actively mode-locked fiber ring laser. The ring-cavity laser is mode-locked by a semiconductor optical amplifier
based on cross-gain modulation. The external CW source is modulated with radio frequency signal by an amplitude modulator
as the external optical pulses and, then, injected into the fiber ring cavity to achieve active mode locking. Further investigating
the laser output characteristics, it indicates that the linewidth of employed CW source affects properties of the generated
ultra-short pulse, such as phase noise and time jitter. Ultra-short pulse at high repetition rate with low time jitter can
be generated by the optimization of CW laser source. 相似文献
10.
We demonstrate a new method of optical pulse generation in regeneratively mode-locked fiber ring lasers (RML-FRLs). The method is based on generating dominant longitudinal modes in the fiber ring cavity by means of a composite cavity structure and their intermode beating at the photodetector incorporated in the regenerative feedback loop. The beat signal is then used as a modulation signal to generate optical pulses in a regenerative mode-locking scheme, thereby eliminating the requirement for a high-Q rf bandpass filter in a conventional RML-FRL. Optical pulses with a repetition frequency of 3.6 GHz have been generated successfully with a supermode noise suppression of more than 48 dB and a low phase noise of -85 dBc/Hz at 10 kHz offset from the carrier frequency. 相似文献
11.
Yoshitomi D Kobayashi Y Kakehata M Takada H Torizuka K Onuma T Yokoi H Sekiguchi T Nakamura S 《Optics letters》2006,31(22):3243-3245
The pulse timing of a mode-locked Er-doped fiber laser was stabilized to a reference pulse train from a Cr:forsterite mode-locked laser by all-optical passive synchronization scheme. The reference pulses were injected into a ring cavity of the fiber laser by using a 1.3-1.5 mum wavelength-division multiplexer. The spectral shift induced by cross-phase modulation between copropagating two-color pulses realizes self-synchronization due to intracavity group-delay dispersion. The rms integration of timing jitter between the fiber laser pulse and the reference pulse was 3.7 fs in a Fourier frequency range from 1 Hz to 100 kHz. 相似文献
12.
Hartl I Schibli TR Marcinkevicius A Yost DC Hudson DD Fermann ME Ye J 《Optics letters》2007,32(19):2870-2872
We report on a passive cavity-enhanced Yb-fiber laser frequency comb generating 230 MW of peak power (3 kW of average power) at a 136 MHz pulse repetition rate. The intracativy peak intensity of 3 x 10(14) W/cm2 for the 95 fs pulse is sufficient to ionize noble gases, such as Xe, Kr, or Ar. The laser system is based on a mode-locked Yb-fiber similariton oscillator in conjunction with a cladding-pumped chirped-pulse fiber amplifier. After recompression, 75 fs duration pulses at a 13.1 W average power are obtained. These pulses are then coherently added inside a passive ring cavity by controlling the fiber oscillator's pulse repetition rate and carrier-envelope offset frequency. This system is well suited for studying high-field phenomena at very high pulse repetition rates. 相似文献
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14.
We describe a novel self-mode-locked Ti:sapphire ring laser that produces 13-fs pulses with peak powers exceeding 1 MW, pulse energies of 13 nJ, and average mode-locked output powers of 1.5 W at a cavity repetition frequency of 110 MHz. A complete resonator analysis describing the optimum mode-locking configuration is presented, together with fringe-resolved autocorrelation and sonogram measurements of the output pulses. 相似文献
15.
We report direct generation of 81 nJ chirped pulses from a room-temperature, Kerr lens mode-locked Cr??:forsterite oscillator operating at 1258 nm. To increase the pulse energy, the pulse repetition rate of the short x-type resonator was lowered from 143 to 4.9 MHz by the addition of a q-preserving multipass cavity, which provided an additional effective optical path length of 59.4 m. The duration of the chirped pulses was around 5.5 ps with a spectral width of 21 nm. The pulses were externally compressed to 607 fs by using a diffraction grating pair. To our knowledge, this is the highest reported pulse energy directly generated from a room-temperature mode-locked Cr??:forsterite laser. 相似文献
16.
Xianhua Wang Guofu Chen Dongfeng Liu Lin Xiu Shuangchen Ruan 《Chinese Journal of Lasers》1992,1(3):193-202
In this paper,complete mode-locking optical pulses have been obtained froman actively mode-locked GaAs/GaAlAs semiconductor laser with grating external cavity.Theshortest optical pulse is 7.3 ps measured by second harmonic generation(SHG)autocorrelator.The repetition rate is 995.12 MHz and the central wavelength is 798.4 nm.The effect ofmodulation frequency,modulation current,and bias current on the optical pulses width areinvestigated. 相似文献
17.
Femtosecond Cr(4+):YAG laser with an L-fold cavity operating at a 1.2-GHz repetition rate 总被引:1,自引:0,他引:1
Pulses of 55-fs width and 1.2-GHz repetition rate at 1.52 mum are generated from an L-fold cavity Cr(4+):YAG laser by optimization of the lasing-beam mode inside the gain medium. The pulse width is comparable with that obtained from a standard Z-fold cavity. The pulses are characterized by a second-harmonic-generation frequency-resolved optical gating method. The pulse shape deviates from a sech(2) function because of its broad shoulders. With further miniaturization it should be possible to extend the Cr(4+):YAG mode-locked operation to multigigahertz rates. 相似文献
18.
A new method to generate high power, short light pulses with a moderate iteration frequency is described. The pulse train of the actively mode-locked Kr laser was sent into a dye-laser amplifier pumped by a N2 laser. The trigger of the N2 laser was generated by dividing the modulation frequency of the mode-locking into moderately low frequency (≈ 50 Hz). Only one pulse in the input train was largely amplified by one N2 laser pulse and the intense short pulses were generated with ≈ 50 Hz iteration. 相似文献
19.
Performance scaling of passively mode-locked ultrashort-pulse fiber oscillators in terms of average power, peak power, and pulse energy is demonstrated. A very-large-mode-area fiber laser in an all-positive group-velocity-dispersion ring cavity configuration with intracavity spectral filter, mode-locked by nonlinear polarization evolution, emits 66 W of average power at 76 MHz repetition rate, corresponding to 0.9 μJ pulse energy. The pulses are dechirped to 91 fs outside the cavity with an average power of 60 W remaining after the compressor. The generated pulse peak power is as high as 7 MW. 相似文献
20.
We describe a mode-locked, diode-pumped Nd:YVO4 laser with a very long optical cavity operating at 1064 nm. High-modulation, InGaAs quantum-well, semiconductor saturable-absorber mirrors were used for passive mode locking, providing a stable train of 13-ps pulses. A novel zero-q-transformation multipass cell provided a variable-length optical cavity as much as 100 m long. The output beam had M2 < 1.1 at average powers of 4.1, 3.9, and 3.5 W at repetition rates of 4.1, 2.6, and 1.5 MHz, respectively. To the best of our knowledge the last of these is the lowest repetition rate ever generated directly from a mode-locked nonfiber solid-state laser without cavity dumping. 相似文献