V. I. Vlasov

Performance of a Tm3+:GdVO4 microchip laser at 1.9 μm

Abstract GdVO 4 as a host for thulium has several advantages for diode pumping. The absorption cross section of thulium in GdVO 4 is considerably stronger and broader than in YAG and YLF, and the spectrum is shifted closer to the emission wavelength of commercially available AlGaAs laser diodes. In our paper we compare the 2 μm transition in Tm:GdVO 4 with the one in Tm:Ho:GdVO 4 . The population dynamics in the two crystals is discussed. Furthermore, we report on the optimisation of a Tm 3+ (6.9 at.%):GdVO 4 microchip laser with respect to high efficiency. CW lasing is established at room temperature in a wavelength range around 1.95 μm. The lowest threshold achieved is 310 mW and the highest slope efficiency is 21%.

New lasers based on c-cut vanadat crystals

Spectroscopic and lasing properties of c-cut Nd-doped Nd:Gd0.7Y0.3VO4, Nd:YVO4, and Nd:GdVO4 crystals were investigated. Spectral tuning from 1062 to 1067 nm was demonstrated. CW, Q-switching and mode-locking regimes for two-color laser operations were realized. A novel THz source based on Q-switch two-color diode-pumped solid state c-cut Nd:GdVO4 laser with Filter Lio as selective element and the GaSe nonlinear optical crystals as convertor was demonstrated. Terahertz radiation with wavelength 436 mm (0.56 THz) was detected. One picosecond laser pulses in mode-locking diode pumped c-cut vanadat lasers with a Kerr-lens and PbS-doped glasses as saturable absorbers are observed.

The investigation of the laser properties of a new class of the mixed YxSc1 − xVO4:Nd3+ crystals

The investigation of structural perfection and laser properties of a new class of mixed vanadates YxSc1 − xVO4:Nd3+ was carried out in this work. The research of the structural perfection of the crystals was carried out by applying the X-ray diffractometer. It was shown that the YxSc1 − xVO4:Nd3+ crystals have a good structural perfection. The lasing experiment shows that the maximal CW output power of 2 W was achieved upon 5.8 W pumping. The maximal slope efficiency of 41.5% was obtained along the [100] crystallographic direction for the π-polarization.

Control of spectral parameters in vanadate lasers

This paper presents laser sources based on a novel methods control of spectral parameters in diode-pumped vanadate lasers. The operation of diode-pumped passively Q-switched variable-cut (8=var, φ=0) Nd:YVO4, Nd:GdVO4 lasers with Cr4+:YAG saturable absorber was experimentally investigated and their relative advantages and drawbacks were compared. The best passively Q-switched performance obtained in the experiments is from the variable-cut (θ=25°, φ=0) laser, which gives the narrowest pulse of 2.5 ns with the highest peak power of 10.3 kW.

Vanadate lasers with {sigma}-polarised radiation

Luminescent and lasing properties at the {sup 4}F{sub 3/2} - {sup 4}I{sub 11/2} transition of {alpha}-cut Nd:YVO{sub 4}, Nd:GdVO{sub 4}, Nd:Gd{sub 1-x}Y{sub x}VO{sub 4} and Nd:Sc{sub 1-x}Y{sub x}VO{sub 4} vanadate crystals are experimentally studied for {pi}- and {sigma}-polarisations. Polarisation dependences of the lasing characteristics of passively Q-switched Nd:YVO{sub 4}, Nd:Gd{sub 1-x}Y{sub x}VO{sub 4} and Nd:Sc{sub 1-x}Y{sub x}VO{sub 4} lasers with Cr{sup 4+}:YAG and V{sup 3+}:YAG Q-switches are investigated. It is shown that the laser wavelengths are different for {pi}- and {sigma}-polarizations. The best characteristics are achieved for the Nd:YVO{sub 4} laser with a Cr{sup 4+}:YAG passive saturable absorber for {sigma}-polarisation (minimum pulse duration shorter than 3 ns, maximum peak power up to 10 kW, maximum peak energy {approx}35 {mu}J at a slope efficiency up to 32%). (lasers)

A comparison of diode pumped 1.4 /spl mu/m lasers based on the different compositions Nd/sup 3+/-doped garnet crystals

This paper demonstrates diode-pumped passive Q-switched mode operation at 1.42-1.44 /spl mu/m wavelength for the /sup 4/F/sub 3/2//spl rarr//sup 4/I/sub 13/2/ transition in garnet crystals co-doped by Nd/sup 3+/and Cr/sup 4+/ ions. A comparison of generation near 1.4 /spl mu/m utilizing the /sup 4/F/sub 3/2//spl rarr//sup 4/I/sub 13/2/ transition in Nd/sup 3+/:YAG, Nd/sup 3+/:Cr/sup 4+/:YAG, Nd/sup 3+/:Cr/sup 3+/:GSGG, Nd/sup 3+/:Cr/sup 3+/:GSAG, Nd/sup 3+/:Cr/sup 3+/:YSGG, and Nd:Cr/sup 4+/:YSGG garnet crystals is presented.

Microchip laser based on an Nd{sup 3+}:GdVO{sub 4} crystal

A diode-pumped microchip laser based on an Nd3+:GdVO4 crystal was investigated. A maximum output power of about 4 W with a differential efficiency of 22% was obtained.A diode-pumped microchip laser based on an Nd{sup 3+}:GdVO{sub 4} crystal was investigated. A maximum output power of about 4 W with a differential efficiency of 22% was obtained. (lasers)

Comparison of spectroscopic and laser properties of Cr4+:YxLu3-xAl5O12 crystals

We present a spectroscopic and lasing investigations of the Cr4+:YxLu3-xAl5O12 crystals, a new laser materials for the infrared region of spectrum. The laser action on the Cr4+:Y1.5Lu1.5Al5O12 crystal is demonstrated. The Cr4+:YxLu3-xAl5O12 saturable absorber Q-switch for a diode side-pumped Nd:GdVO4 laser is performed.