Tunable Cr/sup 4+/:YSO Q-switched Cr:LiCAF laser

To investigate the influence of EL2 deep level on photoconduction of in semi-insulating GaAs (SI-GaAs), a 3 mm-electrode-gap lateral SI-GaAs photoconductive chip was manufactured and tested by using ultrashort pulse laser with 1064 nm wavelength, 10 ns pulsewidth, 3.0 mm light spot diameter and single pulse energy mean of 3.0 mJ. Based on the experimental results and the theory of trapping effect, the photon absorption process of EL2 defects in SI-GaAs is analyzed. For the influence of EL2 deep level, the lifetime of the electron gets shorter and the persistent photoconductivity (PPC) is significant. With increasing of voltage, the decay time constant of photoconduction is reduced and the decay index gets bigger for the ultrashort pulse photoinjection.

Section: Photoabsorption With El2 Deep Levelmentioning

confidence: 80%

Influence of EL2 deep level on photoconduction of semi-insulating GaAs under ultrashort pulse photoinjection

Shi¹,

Guo-dong²

2015

“…Passive Q-switching techniques are simple and convenient, which require minimum optical elements and no [18], Cr 4+ :YSO [19], GaAs and so on. Among these Cr 4+ -doped crystals, Cr 4+ :YAG has become the most important saturable absorber due to its high damage threshold and large thermal conductivity.…”

Section: Introductionmentioning

confidence: 99%

Diode-pumped doubly passively Q-switched Nd:LuVO₄laser with Cr⁴⁺:YAG saturable absorber and GaAs output coupler

Cheng

Zhao

et al. 2009

A diode-pumped doubly passively Q-switched Nd:LuVO4 laser with Cr 4+ :YAG saturable absorber and GaAs output coupler is realized. This laser can generate a shorter and more symmetric pulse profile when compared with pure GaAs. By using two Cr 4+ :YAG saturable absorbers with different small-signal transmissions T0 = 0.71 and T0 = 0.81, the maximum average output power are 1.15 W and 1.31 W at the incident pump power of 11.23 W, corresponding to optical conversion efficiencies of 10.2% and 11.7%. At the same incident pump power, the minimum pulse widths of 4.18 ns and 5.42 ns can be obtained at T 0 = 0.71 and T 0 = 0.81, respectively. The pulse repetition rate and the single-pulse peak power of the laser are also measured.

“…The passive Q-switching technique has the advantage of simple and convenient compared with active Qswitching technique. The passive Q-switching techniques rely on the availability of saturable absorbers such as Cr 4+ :YSO [7], Cr:YAG [8], V:YAG [9], GaAs [10] crystal. Among these, GaAs is an attractive saturable absorber because of its photochemical, thermal stability, large optical nonlinearity and high damage threshold.…”

Section: Introductionmentioning

confidence: 99%

LD-pumped passively Q-switched Nd:LuVO₄laser with a GaAs output coupler

Zhao

et al. 2009

By using GaAs as both a saturable absorber and an output coupler, a laser-diode pumped passively Q-switched Nd:LuVO 4 laser has been realized for the first time to our knowledge. The maximum laser output power of 1.91 W has been obtained at the incident pump power of 12.7 W, corresponding to an optical conversion efficiency of 15%. At this incident pump power, the minimum the pulse width of 3.8 ns has also been obtained at the pulse repetition rate of 952 kHz with peak power of 482 W.