Oleg N. Eremeykin

Electronic mechanism for refractive-index changes in intensively pumped Yb:YAG laser crystals

Refractive-index changes accompanying changes in population of electronic levels of Yb3+ ions in a Yb:YAG laser disk under intense diode and laser pumping have been studied by use of both a highly sensitive polarization interferometer and transient grating testing at 633 nm. The electronic change of the index that is due to excitation of the Yb3+ ions (which have different polarizability of ground state 2F7/2 and excited level 2F5/2) is strongly predominant over the thermal component. The polarizability differences are deltap (1.9 +/- 0.8) x 10(-26) and (1.95 +/- 0.25) x 10(-26) cm3 as measured at 633 nm in interferometric and transient grating experiments, respectively.

Electronic changes of refractive index in intensively pumped Nd:YAG laser crystals

Refractive index changes accompanying changes in population of electron levels of Nd/sup 3+/ ions in a Nd:YAG laser crystal under intensive diode and laser pumping have been studied using a highly sensitive polarization interferometer. An electronic change of the index due to population of the /sup 4/F/sub 3/2/ level is measured to be high (comparable with the thermal component) in the crystal under QCW diode-stack pumping (at 808 nm). The electronic component increased dramatically under pumping by an additional laser (at 266 nm) due to population of a higher-lying level /sup 2/F(2)/sub 5/2/. Analytical estimation reveals a predominating contribution of the well-allowed 4f-5d inter-shell transitions in polarizability of the excited levels /sup 4/F/sub 3/2/ and /sup 2/F(2)/sub 5/2/ both at a testing wavelength of 633 nm and at a wavelength of the strongest laser transition 1064.2 nm.

Efficient continuous-wave generation in a self-organizing diode-pumped Nd:YVO 4 laser with a reciprocal dynamic holographic cavity

A diode-pumped Nd:YVO4 laser is demonstrated that has a reciprocal self-intersecting loop cavity with self-organization by formation of a dynamic holographic grating induced by the generating beam. Continuous-wave high spatial quality generation (M2 < 1.2) with 9.6 W of power and 32% optical efficiency is obtained. Spectral compositions and temporal dynamics are investigated as functions of diode-pumping power.

Self-starting 100-W-average-power laser with a self-adaptive cavity

The numerical and experimental investigation of a self- starting Nd:YAG laser oscillator with a cavity completed by population gratings induced in the laser crystal by generating beams themselves are reported. The spatio- temporal characteristics of the laser comprising three Nd:YAG amplifiers and a saturable absorber were investigated. The generation of single mode beam with an average power of as large as 100 W and high quality was achieved.

Laser generation in polycrystalline Cr{sup 2+}:ZnSe with undoped faces

An original method has been suggested for producing polycrystalline Cr{sup 2+}:ZnSe samples with undoped faces. Generation characteristics of a Cr{sup 2+}:ZnSe laser are studied under pulse-periodic pumping by a Tm{sup 3+}:YLF-laser. The efficiency of converting the pump radiation into laser generation at a wavelength of 2350 nm is 20%. Cr{sup 2+}:ZnSe samples exhibit high resistance to surface breakdown. (lasers)

Mechanisms of refractive index changes in intensively pumped Yb-doped laser crystals

Mechanisms of refractive index changes in intensively pumped Yb-doped crystals (Yb:YAG and Yb:KYW) were studied using both a polarization interferometer and the transient grating method. The electronic component strongly predominated over thermal index changes.

Continuous-wave and pulsed diode-pumped solid-state lasers with reciprocal dynamic holographic cavity

In this report, we present laser systems with the dynamic holographic cavity based on cw diode pumped Nd:YVO/sub 4/ crystals and repetitively pulsed diode pumped Nd:YAG crystals. The spatial and temporal characteristics of the generated laser beams were also studied experimentally.

Spatio-temporal mode analysis in self-organizing diode-pumped solid state lasers on dynamic gratings

A self-organizing laser based on a single diode-pumped Nd:YAG slab with reciprocal cavity completed by dynamic holographic gratings was created and studied. The temporal dynamics, frequency spectrum and spatial characteristics of the generated beam were examined.

A novel solution of a high-average-power Nd:YAG laser with cavity completed by dynamic holographic gratings

In this paper, self-starting laser with a cavity completed by dynamic holographic gratings was presented. And optimization of their architecture for generation of high average power beams with good quality was done. A similar scheme is studied also by use of two Nd:YAG crystals under intensive side-pumping by quasicontinuous wave diode stacks (at 808 nm). Self-starting oscillations for Nd:YAG crystals was investigated by the diode-pumped Nd:YAG rods and slabs.

High average power solid-state lasers on dynamic gratings

Self-starting laser with cavity completed by dynamic holographic gratings induced in the laser crystal by optical waves has recently demonstrated the capability of generating beams with more than two-hundred-Watt average power and a good quality. An important advantage of these lasers is the adaptive property of their cavity provided by the nonlinear dynamic mirror, which is a self-pumped phase-conjugate mirror. In this report we present new results of the investigation of the self-starting lasers and the optimization of their architecture for generation of high average power beams with good quality. The laser systems based on flash-lamp pumped Nd:YAG rods of the large size (O 12 mm /spl times/ 135 mm ) with the cavity completed by the population gratings inside the laser rod were studied and optimized. The imaging transfer technique and the polarization rotation allow for better compensation of the distortions and improve quality of the generated beam with average power up to 250-300 W. The self-starting lasers based on diode-pumped Nd:YAG crystals and grating-formed cavity were also investigated. The self-starting oscillations were achieved. The spatio-temporal characteristics of the generated beams were studied.