Diode-pumped Nd:YAG ceramic laser at 946 nm passively Q-switched with a Cr4+:YAG saturable absorber

We demonstrate a diode-pumped Nd:YAG ceramic laser with emission at 946 nm that is passively Q-switched by single-crystal Cr⁴⁺:YAG saturable absorber. An average output power of 1.7 W is measured under 18.4 W of incident power using an output mirror with transmission T=4%. The corresponding optical-to-optical efficiency is 9.2%. The laser runs at a pulse repetition rate of 120 kHz and delivers pulses with energy of 14 μJ and duration of 80 ns, which corresponds to a peak power of 175 W.     

High peak power laser-diode-pumped passively Q-switched Nd:YVO4/Cr4+:YAG laser

In this paper, we report a high peak power passively Q-switched laser-diode-end-pumped Nd:YVO4/Cr4+:YAG laser polarized along the C axis, generating 4.23-W average power and 18-kW peak power (144-μJ pulse power) with 8.0-ns time duration (29.4-kHz repetition rate) at 1064 nm while the pump power is 21.2 W.     

Comparison between c-cut and a-cut Nd:YVO4 lasers passively Q-switched with a Cr4+:YAG saturable absorber

Comparison between c-cut and a-cut Nd:YVO₄ microchip lasers passively Q-switched with a Cr⁴⁺:YAG saturable absorber is experimentally made. The lower emission cross section of the c-cut Nd:YVO₄ crystal can enhance the passive Q-switching effect to produce a peak power 10 times higher than that obtained with the a-cut crystal. The experimental result further reveals that a c-cut Nd:YVO₄ crystal is a very convenient material for short-pulse (sub-nanosecond) and high-peak-power (>10 kW) lasers. Received:10December2001/Revisedversion:22January2002 / Published online: 14 March 2002     

1097 nm Nd:YVO4 self-Raman laser

An acousto-optically Q-switched self-Raman laser emitting at 1097 nm is demonstrated with a c-cut Nd:YVO₄ crystal, using a fiber-coupled 880 nm diode laser as the pumping source. Raman laser performances in concave-plane and plane-plane oscillating cavities are studied and compared. With an absorbed diode power of 12.4 W and a pulse repetition rate of 50 kHz, the highest output power of 1.45 W is obtained from the plane-plane cavity, corresponding to an optical-to-optical conversion efficiency of 11.7%.     

LD-pumped passively Q-switched Nd:YVO4/YVO4 laser with an Nd3+:Cr4+:YAG saturable absorber

By using a piece of codoped Nd³⁺:Cr⁴⁺:YAG crystal as a saturable absorber, a laser-diode pumped passively Q-switched Nd:YVO₄/YVO₄ laser has been realized. The maximum laser output power of 2.452 W has been obtained at the incident pump power of 8.9 W for an 8.8% transmission of the output coupler at 1064 nm, corresponding to a slope efficiency of 30%. The other output laser characteristics of the laser have also been investigated. The laser with a Nd³⁺:Cr⁴⁺:YAG saturable absorber has a lower threshold pump power and a higher slope efficiency compared to that with a similar small-signal transmission of a Cr⁴⁺:YAG saturable absorber.     

LD-pumped Q-switched Nd:YVO4 self-Raman laser

LD-pumped actively Q-switched Nd:YVO₄ self-Raman laser is presented. The maximum average output power of the self-Raman laser at 1173.6 nm was obtained to be 2.21 W at the incident pump power of 18 W and the pulse repetition frequency (PRF) of 30 kHz, with the corresponding optical conversion efficiency of 12.28%.     

Laser diode pumped actively Q-switched Nd:GdVO4 self-Raman laser operating at 1173 nm

A laser diode pumped actively Q-switched Nd:GdVO₄ self-Raman laser operating at 1173 nm is presented. The maximum output power was 2.26 W at an incident pump power of 18 W, with the corresponding optical conversion efficiency of 12.6%. Two different resonator configurations were investigated in order to achieve high output power and efficiency.     

Cr~(4+)∶YAG被动调Q绿光激光器及其腔外倍频266nm激光的研究

通过合理设计以及精密调控各元件和温控电流,得到了平均功率为27mW、脉冲宽度为15ns、重复频率为16kHz、峰值功率高达108W的Cr4+∶YAG/Nd∶YAG/LBO绿光脉冲激光器。在腔外用I类临界相位匹配的BBO作为四倍频晶体,得到了平均功率为1 2mW的266nm紫外激光,并分析了椭圆光斑产生的原因。     

High-Power passively Q-switched 532 nm green laser by using Nd:YAG/Cr4+:YAG composite crystal

This paper reported a passively Q-switched 532 nm green laser of LD pumped V cavity structure by using Nd:YAG/Cr⁴⁺:YAG composite crystal and the type II phase matching KTP crystal. Under 19.4 W pump power, the average power of the laser pulse up to 1.83 W, with the pulse width of 93.2 ns and repetition frequency of 9.1 kHz.     

Passively Q-switched a-cut Nd:GdVO4 self-Raman laser with Cr:YAG

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.     

Diode-pumped, Cr:YAG passively Q-switched and mode-locked Nd:YVO_4/KTP green laser

The phenomena of simultaneous Q-switching and mode-locking in a diode-pumped Nd:YVO4/Cr:YAG/ KTP green laser are reported and discussed in this paper. With 5.3-W pump power, by using a nearly hemispherical cavity (the cavity length is only 97 mm), the results of modulation depth of 70% and the period of 0.6 ns are obtained, the output power and the repetitive frequency of Q-switched pulse are 90 mW and 12 kHz, respectively.     

LD-pumped passively Q-switched Nd:YVO/LBO red laser with V:YAG

An LD-pumped Nd:YVO₄ passively Q-switched by V:YAG and intracavity frequency doubled by LBO red pulse laser at 671 nm was presented. With 1.6 W incident pump power, average output power of 53 mW, pulse duration (FWHM) of 29.5 ns, pulse repetition rate of 37.2 kHz, peak power of 48.3 W and single-pulse energy of 1.43 μJ were obtained. The stability of pulse energy and repetition rate was better than 3% for 4 h.     

LBO intracavity frequency doubled, Cr:YAG passively Q-switched Nd:YAG green laser

A LD-pumped, LBO intracavity frequency doubled and Cr:YAG passively Q-switched Nd:YAG green laser was reported in this letter. With 600 mW incident pump laser, Q-switched green laser with average power of 27 mW, pulse width of 15.2 ns, repetition rate of 16.4 kHz and peak power of 108.1 W was obtained.     

High-temperature operation of a diode-pumped passively Q-switched Nd:YAG/Cr4+:YAG laser

The output performances of a diode-pumped Nd:YAG laser passively Q-switched by Cr⁴⁺:YAG saturable absorber crystal were investigated function of temperature. Increase of the temperature from 25 to 150°C increased slightly the laser pulse energy, and did not change the pulse duration. Furthermore, an increased absorbed energy of the pump radiation was necessary at temperatures higher than 25°C in order to maintain Q-switch operation. Measurements concluded that Cr⁴⁺:YAG transmission did not vary when temperature increased to 150°C. The decrease of Nd:YAG emission cross section with temperature and the changes of resonator configuration due to thermal effects were considered as main reasons for this behavior. The results of this work are valuable for designing a laser-ignition system for industrial gas engine or automotive industry.     

Diode end-pumped passively Q-switched Nd:YAG ceramic laser with Cr4+:YAG saturable absorber

We report on a diode end-pumped passively Q-switched Nd:YAG ceramic laser. By using a Cr⁴⁺:YAG single crystal with an 80% initial transmission as the saturable absorber, stable Q-switched pulses with a 126-μJ pulse energy, a 12-ns pulse width, and an 8.4-kHz pulse repetition rate have been obtained. The Q-switching performance of the laser under different saturable absorption strengths and output couplings was experimentally investigated.     

A thermally-insensitive passively Q-switched Cr:YAG/Nd:YAG laser

A passively Q-switched laser with Cr⁴⁺:YAG/Nd:YAG composite crystal using a corner cube prism cavity has been realized, in which the corner cube prism is the key element as it aids the compensation of the thermal lens effect of laser crystal. Compared with plane–plane mirror cavities under the same conditions, the stability of the laser performance using the corner cube prism cavity was improved remarkably over temperatures ranging from −40 to 65 °C. The decrease of Nd:YAG stimulated emission cross section with temperature was considered to be the main reason for the increase of average output pulse energy under the same cycle for the two different cavities when the ambient temperature changed −40 to 65 °C. The mode properties produced by the prism cavity were analyzed, and the theoretical results were verified by experimental observations.     

Diode-pumped passively mode-locked Nd:YVO4 laser at 914 nm

We demonstrate, for the first time, to our knowledge, a diode-pumped passively mode-locked Nd:YVO4 laser, operating on the 4F(3/2)-4I(9/2) transition of the neodymium ion at 914 nm. We obtained 8.8 ps pulses at approximately 914 nm at a repetition rate of 94 MHz, and an averaged output power of 87 mW by using a semiconductor saturable absorber mirror.     

Pre-pumped passively Q-switched Nd:YAG/Cr:YAG microchip laser

A pre-pumped passively Q-switched Nd:YAG/Cr:YAG microchip laser is demonstrated with a peak power of 7.5 kW at pulse repetition rate of serveral kilohertzs. The full-width at half-maximum(FWHM)is 734 ps, and the pulse energy is 5.5 μJ with a fundamental spatial mode. In this system, the pre-pumped microchip laser of Nd:YAG/Cr:YAG wafer which is bonded through the thermal-bonding technique has achieved a time jitter value of 12 μs and a Q-switched amplitude instability of 1.26％(15)through the pre-pumped modulation technique.     

High-peak-power,short-pulse-width,LD end-pumped,passively Q-switched Nd:YAG 946 nm laser

High-peak-power, short-pulse-width diode pumped 946 nm Nd:YAG laser in passively Q-switching operation with Cr⁴⁺:YAG is reported. The highest average output power reaches 3.4 W using the Cr⁴⁺:YAG with initial transmissivity T₀=95%. When the T₀=90% Cr⁴⁺:YAG is employed, the maximum peak power of 31.4 kW with a pulse width of 8.3 ns at 946 nm is generated.