Pulse duration limitations in a diode-pumped femtosecond Kerr-lens mode-locked Cr:LiSAF laser

Received: 20 February 1997/Revised version: 24 April 1997     

Generation of 12-fs pulses from a diode-pumped Kerr-lens mode-locked Cr:LiSAF laser

We demonstrate 12-fs-pulse generation from a diode-pumped Kerr-lens mode-locked Cr:LiSAF laser. This is to our knowledge the shortest pulse ever produced from a mode-locked Cr:LiSAF laser. Based on an improved estimation of the intracavity dispersions, we utilized BK7 glass for the Brewster-prism-pair material.     

White-light frequency comb generation with a diode-pumped Cr:LiSAF laser

We have created a broad spectrum spanning more than an optical octave by launching femtosecond pulses from a battery operated Cr:LiSAF laser into a photonic crystal fiber. Despite the massive broadening in the fiber, the comb structure of the spectrum is preserved, and this frequency comb is perfectly suited for applications in optical frequency metrology.     

Pulse timing stabilization of a mode-locked Cr:LiSAF laser

The pulse repetition frequency of a mode-locked Cr:LiSAF laser has been stabilized to an electrical reference oscillator by use of an electrical feedback technique. The phase and frequency differences between the laser and the reference are detected by use of a digital phase detector, which overcomes the difficulties of a conventional double-balanced mixer. We obtained rms timing jitters of 20 fs (25 mHz-10 kHz) and 7 fs (25 mHz-1 kHz) relative to the reference.     

High-average-power diode-pumped femtosecond Cr:LiSAF lasers

Received: 27 February 1997/Revised version: 14 April 1997     

Directly diode-pumped Kerr-lens mode-locked Cr4+:YAG laser

A directly diode-pumped Kerr-lens mode-locked Cr4+:YAG laser is demonstrated for what is to our knowledge the first time. Pulses as short as 65 fs with up to 30 mW of average output power, at a central wavelength of 1569 nm, were obtained at a repetition rate of 100 MHz. Low-loss chirped mirrors have been used for dispersion compensation up to the third order. Comparison with an Yb-fiber-pumped configuration shows good prospects for improvement.     

Wall paper single-walled carbon nanotubes absorber for passively mode-locked Nd: GdVO4 laser

A novel and low-cost wall paper single-walled carbon nanotubes (SWCNTs) absorber was fabricated by high viscosity of polyvinyl alcohol (PVA) aqueous solution and vertical evaporation technique. Sandwich structure wall paper SWCNT (SSWA-SWCNT) absorber was constructed by a piece of wall paper SWCNT absorber, a piece of round quartz and an output coupler mirror. We exploited it to realize mode locking operation in a diode-pumped Nd: GdVO₄ laser. A pulse duration of 9.6 ps was produced with an average power of 870 mW. The stable mode locking operation was obtained when the average power is less than 300 mW.     

Correlation between amplitude and phase noise in a mode-locked Cr:LiSAF laser

The coherence function between the amplitude and phase fluctuations of a mode-locked Cr:LiSAF laser has been measured with a time-domain demodulation technique. A relatively large correlation has been found for the noise components that originate in the pump-power fluctuation. Through an examination of the modulation-induced change in the noise power spectral densities, the influences of pump-power and cavity-length variations on these fluctuations have been investigated.     

All-solid-state diode-pumped Cr:LiSAF femtosecond oscillator and regenerative amplifier

3+ :LiSrAlF₆ (Cr:LiSAF) regenerative amplifier, seeded by a diode-pumped Cr:LiSAF femtosecond oscillator. The amplifier produced pulses of less than 200 fs duration and greater than 1 μJ energy at repetition rates of up to 25 kHz. Received: 27 February 1997/Revised version: 16 April 1997     

Femtosecond mode-locked Yb fiber laser for single-mode fiber chirped pulse amplification system

High-peak-power laser systems are based on the chirped pulse amplification (CPA) technique. CPA laser system needs a mode-locked laser oscillator for stable ultrashort pulse laser generation. We report a single-mode fiber CPA system which consists of stable mode-locked Yb-doped fiber laser oscillator with a wide tuning range, chirped fiber Bragg grating stretcher, and two Yb-doped fiber amplifiers. The single-mode fibers can generate high-quality and single-mode beams which are stable for long time.     

Passively mode-locked Yb:LYSO laser with a reflection type single-walled carbon absorber

Passively diode-pumped Yb:LuYSiO₅ (Yb:LYSO) laser mode locked by reflection-type single walled carbon nanotubes saturable absorber (RSWCNT-SA) is reported for the first time. Under the absorbed pump power of 13.23 W, continuous wave (CW) mode-locked pulses were generated with the maximum average output power of 157 mW. We obtained pulses as short as 4.0 ps around a center wavelength of 1038.3 nm. The peak power and the single pulse energy of the mode-locked laser were 0.38 kW and 1.52 nJ, respectively.     

LD end-pumped passively mode-locked Nd:YVO<Subscript>4</Subscript> laser with single-walled carbon nanotubes

We demonstrate a LD end-pumped passively mode-locked Nd:YVO₄ laser using a single-walled carbon nanotubes saturable absorber (SWCNT-SA). The SWCNT wafer was fabricated by electric arc discharge method on quartz substrate with absorption wavelength of 1064 nm. At the absorbed pump of 15.8 W, an output power of 750 mW CW (continuous wave) mode-locked laser pulse was achieved with the repetition of 79.7 MHz, corresponding to optical-optical efficiency of 4.75%.     

100-fs diode-pumped Yb:KGW mode-locked laser

We have developed a mode-locked diode-pumped Yb:KGW laser generating 100-fs pulses with an output power of 126 mW. The corresponding optical spectrum has a 13.4-nm FWHM bandwidth and is centered at 1037.4 nm. In the multiple-pulsing regime, bound states of solitons with rotating phase difference and separated by 917.5 fs were observed. We compare the performance of the Yb:KGW crystal to that of an Yb:KYW crystal with the same thickness and Yb concentration. PACS 42.55.Rz; 42.65.Re; 42.65.Tg     

Flexible pulses from carbon nanotubes mode-locked fiber laser

We demonstrate a flexible erbium-doped pulsed fiber laser which achieves the wavelength and pulse width tuning by adjusting an intracavity filter. The intracavity filter is flexible to achieve any of the different wavelengths and bandwidths in the tuning range. The wavelength and width of pulse can be tuned in a range of ~ 20 nm and from ~0.8 ps to 87 ps,respectively. The flexible pulsed fiber laser can be accurately controlled, which is insensitive to environmental disturbance.     

Diode-pumped tunable laser with dual Cr：LiSAF rods

We propose and demonstrate a simple approach to lower the thermal quenching effect and improve the output power of Cr:LiSAF lasers, which is accomplished by employing two laser rods. The resonator contains two laser rods and is designed by using two ``X' folding cavities in cascade. A tunable laser output of $\sim $ 180\,mW has been achieved with the pump of single-striped laser diodes. Compared with lasers using single gain rod, the laser with dual rods shows less severe thermal effect and increases the output by more than two times.     

High-power diode-pumped mode-locked Yb:YAG ceramic laser

A high-power diode-pumped passively mode-locked Yb:YAG ceramic laser was demonstrated. An average output power of 3.80W with a pulse duration of 433 fs at a repetition rate of 90.9MHz was obtained at a wavelength of 1050 nm using a 2% output coupler. A peak power of 96.5kW was also obtained. To the best of our knowledge, these are the highest reported average power and peak power for a diode-pumped mode-locked Yb:YAG ceramic laser.     

Broadly tunable femtosecond Cr:LiSAF laser

We demonstrate wavelength tunability of femtosecond pulses over a range of more than 50 nm from a diode-pumped Cr:LiSAF laser. The mode-locking mechanism can be explained by soliton mode locking that is started and stabilized by a broadband semiconductor saturable-absorber mirror designed for low loss over the full reflection bandwidth of the underlying Bragg mirrors, which ultimately limits tunability. We obtain 45-fs pulses at 105-mW average output power and a maximum mode-locked average output power of 125 mW with 60-fs pulses.     

550 MHz carbon nanotube mode-locked femtosecond Cr:YAG laser

We demonstrate a femtosecond Cr:YAG laser mode-locked by a carbon nanotube saturable absorber mirror(CNT-SAM) at a repetition rate of 550 MHz. By employing the CNT-SAM, which exhibits a modulation depth of 0.51% and a saturation fluence of 28 μJ∕cm~2 at 1.5 μm, we achieved a compact bulk Cr:YAG laser with selfstarting mode-locked operation near 1.5 μm, delivering an average output power of up to 147 m W and a pulse duration of 110 fs. To our knowledge, this system provides the highest repetition rate among reported CNT-SAM mode-locked Cr:YAG lasers and the shortest pulse duration among saturable absorber mode-locked Cr:YAG lasers with repetition rates above 500 MHz.     

Q-switched and mode-locked diode-pumped Nd:YAG laser with an LT-GaAs

Simultaneous Q-switching and mode-locking (QML) is accomplished in a diode-pumped Nd:YAG laser using low-temperature GaAs (LT-GaAs) as the saturable absorber, which also acts as an output coupler at the same time. The repetition rate of the Q-switched envelope increased from 25 to 40 kHz as the pump power increased from 2.2 to 6.9 W. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of 714 MHz. A maximum average output power of 770 mW was obtained.     

宽谱可调谐的全固化Cr:LiSAF激光器

报道了调谐范围达130 nm的的V型腔端面泵浦全固化Cr:LiSAF激光器。研究了V型腔结构的重要参数,优化了腔型设计以提高激光器的效率。激光器自由运转输出时,斜效率最高达39.2%,泵浦阈值最低为32.8 mW。对比分析了双折射滤光片(BF)和棱镜的调谐效果。在腔内插入BF调谐,实现了783~913 nm连续可调谐输出,在840 nm处获得115 mW的最大输出功率,在800~900 nm的区间内,输出功率超过80 mW。用棱镜作为调谐元件,调谐范围达802~887 nm,最大输出功率为6.5 mW。从调谐范围和输出功率看,BF的调谐效果更好。