60-fs pulses from a diode-pumped Nd:glass laser

We demonstrate 60-fs pulses with an average output power of 84 mW from a diode-pumped Nd:glass laser mode locked by a low-finesse antiresonant Fabry-Perot saturable absorber (A-FPSA). The mode-locked spectrum spreads over most of the available Nd:glass fluorescence bandwidth. At increased pulse energy fluence or decreased negative group-velocity dispersion, multiple pulsing was observed. We experimentally characterize this behavior, which can be explained by the saturation behavior of the A-FPSA and the limited available gain bandwidth. These considerations are significant for the design of saturable absorbers to achieve stable passive mode locking.     

Efficient and tunable diode-pumped femtosecond Yb:glass lasers

Diode-pumped Yb:phosphate and Yb:silicate glass lasers have been passively mode locked for the first time to the authors' knowledge. Reliable self-starting mode locking without critical cavity alignment has been achieved with intracavity semiconductor saturable-absorber mirrors and soliton mode locking. We generated pulses as short as 58 fs with the Yb:phosphate laser and 61 fs with the Yb:silicate laser at average output powers of 65 and 53 mW, respectively. The pulse repetition rate was 112 MHz. Additionally, we demonstrated tunability of femtosecond pulses from 1025 to 1065 nm for the Yb:phosphate and from 1030 to 1082 nm for the Yb:silicate glasses. The highest mode-locked output power was 405 mW, with 183-fs pulses from the phosphate glass. The diode pump power was 1.68 W, corresponding to 24% optical-to-optical efficiency. The highest cw output power was 510 mW at the same incident pump power.     

Diode-pumped femtosecond Yb:KGd(WO(4))(2) laser with 1.1-W average power

We demonstrate what is to our knowledge the first mode-locked Yb:KGd(WO(4))(2) laser. Using a semiconductor saturable-absorber mirror for passive mode locking, we obtain pulses of 176-fs duration with an average power of 1.1 W and a peak power of 64 kW at a center wavelength of 1037 nm. We achieve pulses as short as 112 fs at a lower output power. The laser is based on a standard delta cavity and pumped by two high-brightness laser diodes, making the whole system very simple and compact. Tuning the laser by means of a knife-edge results in mode-locked pulses within a wavelength range from 1032 to 1054 nm. In cw operation, we achieve output powers as high as 1.3 W.     

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.     

16.2-W average power from a diode-pumped femtosecond Yb:YAG thin disk laser

We demonstrate a power-scalable concept for high-power all-solid-state femtosecond lasers, based on passive mode locking of Yb:YAG thin disk lasers with semiconductor saturable-absorber mirrors. We obtained 16.2 W of average output power in pulses with 730-fs duration, 0.47-muJ pulse energy, and 560-kW peak power. This is to our knowledge the highest average power reported for a laser oscillator in the subpicosecond regime. Single-pass frequency doubling through a 5-mm-long lithium triborate crystal (LBO) yields 8-W average output power of 515-nm radiation.     

Femtosecond self mode locking of Yb:fluoride phosphate glass laser

Passive cw mode locking of an ytterbium-doped fluoride phosphate glass laser is demonstrated, for what we believe to be the first time, based solely on the Kerr effect in the active medium in a resonator with dispersion compensation. Nearly bandwidth-limited pulses as short as 160fs are generated at ~1040 nm. We obtain average output powers as high as 250mW at 170-MHz repetition rate with absorbed pump power as low as 1.2W.     

Passively mode-locked 914-nm Nd:YVO4 laser

We demonstrate what is to our knowledge the first mode-locked Nd:YVO4 laser operating on the 4F3/2-4I9/2 transition at 914 nm. Using a semiconductor saturable-absorber mirror for passive mode locking, we have obtained 3-ps pulses at a repetition rate of 233.8 MHz. The laser is based on a standard delta cavity and is pumped by a Ti:sapphire laser. We obtained an average output power of 42 mW through one mirror and an accumulated output power of approximately 150 mW (through all cavity mirrors) at a pump power of 1.4 W.     

Passively mode-locked Nd:LuVO(4) laser with a GaAs wafer

We report on the passive mode locking of a diode-pumped Nd:LuVO(4) laser with a GaAs wafer as output coupler. Using the interference modulation effect of the GaAs wafer, high-power continuous-wave mode locking with a pulse width of about 7.1 ps and an average output power of 3.11 W was achieved. Our result shows that Nd:LuVO(4) could be an excellent gain medium for diode-pumped high-power mode-locked lasers.     

Diode-end-pumped Nd:CaYAlO4 mode locked laser

A diode pumped passively mode locked Nd:CaYAlO₄ (Nd:CYA) laser is demonstrated for the first time to the authors' knowledge. Using a V-shaped cavity and a semiconductor saturable absorbing mirror (SESAM), self-started mode locking of the laser is experimentally achieved. The mode-locked pulses are as short as 3.9 ps at a central wavelength of 1080.2 nm. The mode-locked laser produced a maximum average output power of 2.25 W with a slope efficiency of 23.2%.     

Passive mode locking of a diode-end-pumped Nd:GdVO4 laser with a semiconductor saturable absorber mirror

We report an end-pumped and passive mode-locking all-solid-state laser. The laser consists of a Nd:GdVO4 crystal and a linear resonator with a semiconductor saturable absorber mirror that yield mode locking. We achieved stable continuous-wave mode locking with an 8-ps pulse duration at a 154-MHz repetition rate. The average output power was 600 mW with 4 W of pump power. To our knowledge this is the first report of the use of a Nd:GdVO4 crystal for mode locking with a semiconductor saturable absorber mirror.     

5.1-ps passively mode-locked Nd:Gd0.42Y0.58VO4 laser with a LT-GaAs absorber

We propose a diode end-pumped passively mode-locked Nd: Gd0.42 Y0.58 VO4 (Nd: GdYVO4) laser at 1064nm using a GaAs absorber grown at low temperature as the output coupler.Stable continuous-wave (CW) mode locking with a 5.1-ps pulse duration at a repetition rate of 113MHz is obtained.The maximum average output power is 2.29W at the incident pump power of 12W with the slope efficiency of about 24.8%.     

Fabrication and characterization of double-wall carbon nanotube absorber for passive mode-locked Nd:GdVO<Subscript>4</Subscript> laser

Using the vertical evaporation technique we fabricated saturable absorbers by transferring the double-wall carbon nanotubes (DWCNT) onto a hydrophilic quartz substrate. The fast recovery time and the saturation intensity of the absorber were measured to be 228 fs and 130 μJ/cm², respectively, at 1060 nm. The modulation depth of the absorber was about 3.7%. Passive mode-locked Nd:GdVO₄ laser was demonstrated. The continuous wave mode-locked pulses pulse duration is 5.6 ps and the largest average output power is 1.2 W at the pump power of 9.5 W. To the best of our knowledge, this is the first demonstration of high power continuous wave mode locking laser with DWCNT absorber.     

Femtosecond Cr:forsterite laser diode pumped by a double-clad fiber

We present a compact, all-solid-state femtosecond Cr:forsterite laser. The laser is pumped by diodes through a double-clad fiber. Kerr-lens mode locking is initiated and stabilized by a semiconductor saturable-absorber mirror with a single InGaAs quantum well. This system generates transform-limited 80-fs pulses near 1.3microm . An average power of 68 mW with fluctuation of much less than 1% is obtained with 3.8 W of absorbed pump power. The stability, efficiency, compactness, and potential for scaling to higher power of this system make it an attractive short-pulse source for applications.     

连续锁模Nd：YVO4激光器实现1 GHz高频输出

LD抽运全固体Nd:YVO4激光器在连续锁模状态运转下获得了高达1 GHz的重复频率.实验中采用半导体可饱和吸收镜作为锁模元件.利用透过率只有0.8%的输出镜以及可获得较小抽运光斑的2 W LD作为抽运源来优化激光器设计,有效地抑制了调Q锁模状态的运转.低的激光器振荡阈值（35 mW）和连续锁模阈值(0.8 W)显示了饱和吸收体低的插入损耗和激光器合理的设计.在最大抽运1.6 W时获得了210 mW的平均输出功率.     

Stretched pulse Yb(3+)silica fiber laser

We report what we believe to be the first results on short-pulse generation in Yb(3+) :silica fiber. By applying the stretched pulse technique in a unidirectional, polarization-switch Yb(3+) fiber laser incorporating a prism-based dispersive delay line, we obtain self-start mode locking and 100-pJ pulses that can be compressed to give clean chirp-free <100-fs pulses. We believe such sources to have great potential for use not only in all-solid-state, high-power femtosecond pulse systems based on Yb(3+) :silica glass but also as seeds for conventional Nd(3+) :glass amplifier chains.     

Stable multigigahertz pulse-train formation in a short-cavity passively harmonic mode-locked erbium/ytterbium fiber laser

We demonstrate a short-cavity erbium-ytterbium fiber laser that is passively mode locked by a saturable Bragg reflector with a fundamental repetition rate of 235 MHz . The laser operates in the soliton regime and under passive harmonic mode locking with 11 pulses in the cavity and produces output pulse trains at 2.6 GHz with transform-limited 270-fs pulses and 1.6 mW of average power. Within the cavity the multiple pulses form a stable pattern with fixed, nearly equal pulse-to-pulse temporal spacings, causing the output pulse train to have timing offsets of less than 15 ps. A slow gain-recovery model is proposed to explain the pulse-train self-organization.     

Diode-pumped passively mode-locked Nd:KGd(WO(4))(2) laser with 1-W average output power

Continuous-wave passive mode locking of a diode-pumped Nd:KGd(WO(4))(2) laser is demonstrated. The use of a saturable Bragg reflector as the mode-locking element permits the generation of 6.3-ps pulses, assuming a sech(2) pulse shape. An output power of 1 W was obtained, which corresponds to a slope efficiency of 34.5%.     

Nonlinear femtosecond pulse compression at high average power levels by use of a large-mode-area holey fiber

We demonstrate that nonlinear fiber compression is possible at unprecedented average power levels by use of a large-mode-area holey (microstructured) fiber and a passively mode-locked thin disk Yb:YAG laser operating at 1030 nm. We broaden the optical spectrum of the 810-fs pump pulses by nonlinear propagation in the fiber and remove the resultant chirp with a dispersive prism pair to achieve 18 W of average power in 33-fs pulses with a peak power of 12 MW and a repetition rate of 34 MHz. The output beam is nearly diffraction limited and is linearly polarized.     

Passive mode locking of a diode-pumped Nd:Gd 0.64 Y 0.36 VO 4 laser with a GaAs saturable absorber mirror

We report a diode-pumped Nd:Gd_0.64Y_0.36VO₄ laser passively mode locked by using a GaAs saturable absorber mirror. Both the Q-switched and continuous-wave (CW) mode locking were experimentally realized. The CW mode-locked pulses have a pulse width of about 8.8 ps at a repetition rate of 161.3 MHz. Limited by the available pump power, a maximum output power of 2.47 W was obtained for the CW mode-locked pulses with a slope efficiency of about 26.6%.     

7.6-W diode-pumped femtosecond Yb:KGW laser

We have demonstrated a high power diode-pumped mode-locked femtosecond Yb:KGW laser with semiconductor saturable absorber mirror(SESAM). By using an output coupler with 10% transmittance, the laser delivered 160-fs pulses with average output power of 7.6 W at a repetition rate of 78 MHz, corresponding to pulse energy of 97 nJ and peak power of 606 kW.