Experiments of a diode-pumped Nd : GdVO4/LT-GaAs Q-switched and mode-locked laser

A diode-pumped passively Q-switched mode-locked (QML) Nd:GdVO4 laser with a low temperature GaAs (LT-GaAs) saturable absorber is presented. The maximal Q-switched mode-locked average output power was 798 mW with the Q-switched envelop having a repetition rate of 125 kHz. The mode-locked pulse trains inside the Q-switched pulse envelope had a repetition rate of similar to 750 MHz. The laser properties of the operational parameters on the pump power were also investigated experimentally.

Diode-end-pumped passively CW mode-locked Nd : YLF laser by the LT-In0.25Ga0.75As absorber

We have demonstrated a self-staring passively continuous-wave mode-locked diode end-pumped Nd:YLF laser with a semiconductor saturable absorber mirror of single-quantum-well (In0.25Ga0.75As) grown by metal-organic chemical-vapor deposition technique at low temperature. The saturable absorber was used as nonlinear absorber and output coupler simultaneously. Stable pulse duration of 3 ps has been achieved at the repetition rate of 98 MHz. The average output power was 530 mW at 1053 nm under the incident pump power of 10 W, corresponding to the peak power of 1.8 kW and pulse energy of 5.4 nJ.

Experimental investigation of intracavity absorber low temperature GaAs in diode-pumped Nd : GdVO4 laser

A passively Q-switched and mode-locked diode-pumped Nd:GdVO4 laser was demonstrated using a low-temperature-grown GaAs wafer (LT-GaAs) as an intracavity saturable absorber. The maximal Q-switched mode-locked average output power was 750 mW with the Q-switched envelop having a repetition rate of 167 kHz. The mode-locked pulse trains inside the Q-switched pulse envelope had a repetition rate of similar to 790 MHz.

GaAs absorber grown at low temperature used in passively Q-switched diode pumped solid state laser

We report, for the first time to the best of our knowledge, on a passively Q-switched Nd:YVO4 laser with a GaAs absorber grown at low temperature (LT) by metal organic vapor phase expitaxy. Using the LT GaAs absorber as well as an output coupler, a passively Q-switched laser whose pulse duration is as short as 90 ns, was obtained.

End-pumped continuous-wave passively modelocked Nd : YVO4 laser with low pump power

A simple cw mode-locked solid-state laser, which is end-pumped by a low-power laser diode, was demonstrated by optimizing the laser-mode size inside the gain medium. The optimum ratio between mode and pump spot sizes inside the laser crystal was estimated for a cw mode-locked laser, taking into account the input pump power. Calculation and experiment have shown that the optimum ratio was about 3 when the pump power is 2 W, which is different from the value regularly used in passively mode-locked solid-state lasers. This conclusion is also helpful in increasing the efficiency of high-power ultrashort lasers. (C) 2006 Society of Photo-Optical Instrumentation Engineers.

Q-switched and mode-locked diode-pumped Nd : GdVO4 laser with low temperature GaAs saturable absorber

Low temperature GaAs (LT-GaAs) was successfully grown at the temperature of 550 degrees C by metal organic vapor phase epitaxy on a semi-insular GaAs substrate. With such an absorber as well as an output coupler we obtain Q-switched mode-locked (QML) 1064 nm Nd:GdVO4 laser pumped by diode laser with high repetition rate, formed with a simple flat-flat cavity. The repetition rate of the Q-switched envelope increased from 100 to 660 kHz as the pump power increased from 2.28 to 7.29 W. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of similar to 1.36 GHz. A maximum average output power of 953 mW was obtained. The dependence of the operational parameters on the pump power was also investigated experimentally. (C) 2005 Elsevier B.V. All rights reserved.

Passively Q-switched and mode-locked diode-pumped Nd : YVO4 laser with LT-GaAs output coupler

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 mu J, respectively. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of 780 MHz. (C) 2005 Elsevier B.V. All rights reserved.

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. (c) 2005 Elsevier GmbH. All rights reserved.

A passively mode-locked diode-end-pumped Nd : YAG laser with a semiconductor saturable absorber mirror grown by metal organic chemical vapour deposition

We report the experimental results of a mode-locked diode-end-pumped Nd:YAG laser with a semiconductor saturable absorber mirror (SESAM) from which we achieved a 10 ps pulse duration at 150 MHz repetition rate. The SESAM was grown by metal organic chemical vapour deposition at low temperature. The recovery time was measured to be 0.5 ps, indicating the potential pulse compression to sub-picoseconds.

Diode-pumped passively Q-switched Yb : YAG microchip laser with a GaAs as saturable absorber

A passively Q-switched Yb: YAG microchip laser has been constructed by using a doped GaAs as the saturable absorber as well as the output coupler. At 13.5 W of pump power the device produces high-quality 3.4 muJ 52 ns pulses at 1030nm with a pulse repetition rate of 7.8kHz in a TEM00-mode.

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. (C) 2003 Optical Society of America.

Absolute measurement of detector quantum efficiency using optical parametric down-conversion pumped by femtosecond laser pulses

Absolute measurement of detector quantum efficiency using optical parametric down-conversion has been extensively studied for the case of a continuous wave pump. In this paper, we have used the temporally and spatially correlated properties of the down-converted photon pairs generated in a nonlinear crystal pumped by a femtosecond laser pulse to perform an absolute measurement of detector quantum efficiency. The measured detector quantum efficiency is in excellent agreement with the measured value in the conventional way. A lens with a long focal length was adopted for efficiently increasing the intensity of the down-conversion entangled photon source.

A 20.1 W Solid-State Laser Pumped by 887 nm with High Efficiency and TEM00 Mode

High efficiency, TEM00 mode, high repetition rate laser pumped by 887 nm is reported. 20.1 W output laser emitting at 1064 nm is achieved in a 0.3 at % Nd-doped Nd:YVO4, which absorbs pumping light of 30.7 W at 887 nm. The opto-optic efficiency and the slope efficiency are 65.5 and 88.5%, respectively. The stable Q-switching operation worked well at 100 kHz and the beam quality is near diffraction-limit with M-2 factor measured as M-2 approximate to 1.2. And the pulse waveform is analyzed in this paper.

LD side-pumped high beam quality passive Q-switched and mode-locked Nd:YAG laser based on SESAM

We report a LD side-pumped fundamental-mode (Mx(2) = 1.35 and My(2) = 1.27) passive Q-switched and mode-locked Nd:YAG laser based on a semiconductor saturable absorber mirror (SESAM). At a pump current of 12.5 A, the average output power of 5.68 W with 80 kHz repetition rate and 2 mu s pulse width of the Q-switched envelope was generated. The repetition rate of the mode-locked pulse within the Q-switched envelope of 88 MHz was achieved.

Low heat and high efficiency Nd:GdVO4 laser pumped by 913 nm

A Nd:GdVO4 crystal is pumped directly into its emitting level at 913 nm for the first time to the best of our knowledge. 3.35 W output laser emitting at 1063 nm is achieved in a 1.1 at.% Nd-doped Nd:GdVO4. The crystal absorbs pumping light of 4.30 W at 913 nm and produces a very low quantity of heat with the opto-optic conversion efficiency of 77.2%. The average slope efficiency is 81.2% from 0.21 W, at the threshold, to 4.30 W of absorbed pump power. Because of the very weakly thermal effect, the near-diffraction-limit beam is easily obtained with beam quality factor of M-2 approximate to 1.1.