Ravil Yu. Abdulsabirov

Ce/sup 3+/-activated fluoride crystals as prospective active media for widely tunable ultraviolet ultrafast lasers with direct 10-ns pumping

New possibilities have been investigated for recently developed solid-state tunable ultraviolet (UV) laser materials such as Ce/sup 3+/ ion-activated LuLiF/sub 4/ (LLF) and LiCaAlF/sub 6/ (LiCAF). With their broad-gain width, demonstrated reliability, and high efficiency, they are attractive for ultrashort pulse generation and amplification. To prove that, we have demonstrated UV picosecond-pulse amplification using Ce:LLF. For such new laser materials, we proposed a passive self-injection seeding scheme for the direct generation of short-pulse trains, which does not require CW operation capability or an external short-pulse seeding laser, Using this simple scheme, a UV sub-nanosecond pulse train is directly and passively generated from Ce:LLF pumped by a standard 10-ns KrF excimer laser, and Ce:LiCAF pumped by the fourth harmonic of a conventional 10-ns Q-switched Nd:YAG laser. >

Ce 3+ :LuLiF 4 as a broadband ultravioletamplification medium

Ce(3+):LuLiF(4) is shown to have a broad gain spectrum, which is attractive for short-pulse applications. A large small-signal gain over 6 dB/cm and a sufficiently large saturation fluence of 50 mJ/cm(2) were observed for 10-ns probe pulses under KrF excimer laser pumping. In a confocal four-pass configuration, 17-dB amplification was demonstrated for 325-nm picosecond pulses, and 20-dB gain was demonstrated for cw laser light.

ULTRAVIOLET SHORT PULSES FROM AN ALL-SOLID-STATE CE:LICAF MASTER-OSCILLATOR-POWER-AMPLIFIER SYSTEM

We have developed an all-solid-state master-oscillator-power-amplifier system employing Ce:LiCAF, a new degradation-free tunable ultraviolet laser medium pumped by the fourth harmonic of conventional 10-ns Q -switched Nd:YAG lasers. The low- Q , short-cavity Ce:LiCAF master oscillator produced a satellite-free 1-ns pulse under appropriate pumping-fluence control. 18% energy extraction with sufficient gain was achieved in a single-stage, confocal, double-pass amplifier. As a result, 289-nm, 1-ns, 14-mJ pulses were efficiently obtained from this simple laser system.

Ce{sup {bold 3}+}:LuLiF{sub 4} as a broadband ultraviolet amplification medium

Ce(3+):LuLiF(4) is shown to have a broad gain spectrum, which is attractive for short-pulse applications. A large small-signal gain over 6 dB/cm and a sufficiently large saturation fluence of 50 mJ/cm(2) were observed for 10-ns probe pulses under KrF excimer laser pumping. In a confocal four-pass configuration, 17-dB amplification was demonstrated for 325-nm picosecond pulses, and 20-dB gain was demonstrated for cw laser light.

All-Solid-State Tunable Ultraviolet Subnanosecond Laser with Direct Pumping by the Fifth Harmonic of a Nd:YAG laser.

We report what we believe is the first all-solid-state tunable ultraviolet laser pumped by the fifth harmonic of a Q-switched Nd:YAG laser. Our laser based on a Ce(3+):LiLuF(4) active medium stably generates a single, satellite-free, 0.88-ns pulse under 5-ns, 10-Hz repetition rate pumping conditions. A novel tilted-incident-angle side-pumping scheme resulted in a simple laser-cavity design.

VUV and UV fluorescence and absorption studies of Pr(3+)-doped LiLuF(4) single crystals.

The laser-induced fluorescence spectrum of LiLuF(4):Pr(3+) single crystals, pumped by an F(2) pulsed-discharge molecular laser at 157 nm, was obtained in the VUV and UV regions of the spectrum at room temperature. A number of new fluorescence peaks were observed for the first time to our knowledge. They were assigned to the dipole-allowed transitions 4f5d ? 4f(2) of Pr(3+) ion. In addition, the absorption spectrum of the crystal samples was recorded. The positions of the bands with the 4f5d configuration were found to be 46 412, 53 267, and 63 397 cm(-1) from the ground state, (3)H(4), of the Pr(3+) ion. The edge (onset) of the 4f5d bands was at 45 100 cm(-1).

On the 4f25d→4f3 interconfigurational transitions of Nd3+ ions in K2YF5 and LiYF4 crystal hosts

Abstract The Laser Induced Fluorescence (LIF) spectrum of K 2 YF 5 :Nd 3+ (PFYK:Nd) and LiYF 4 :Nd 3+ (YLF:Nd) single crystals, pumped by the fluorine F 2 pulsed discharge molecular laser at 157.6 nm, was obtained in the Vacuum Ultraviolet (VUV) region of the spectrum. The fluorescence peaks were assigned to the 4f 2 5d→4f 3 dipole allowed transitions of the Nd 3+ ion. The 180 nm band of the LIF spectrum from the crystals indicates that the 4f 2 5d→4f 3 dipole transitions originate from the low Stark components of the 4 K 11/2 level of the 4f 2 5d configuration. The absorption spectrum of the crystal samples in the VUV was obtained as well and spectroscopic assignment of the levels of the 4f 2 5d configuration was made. The electric crystal field splits all the levels of single and mixed configuration. The energy of the Stark components of the 4f 2 5d configuration in YLF:Nd was shifted by few hundred cm −1 relative to that of PFYK:Nd. We observed eleven and nine dipole transitions, between the 4 I 9/2 ground level of the 4f 3 configuration and the Stark components of the levels of the 4f 2 5d configuration of the Nd 3+ ion, in YLF and PFYK crystal hosts, respectively.

Vacuum-ultraviolet interconfigurational 4f 3 → 4f 2 5d absorption and emission studies of the Nd 3+ ion in KYF, YF, and YLF crystal hosts

The laser-induced vacuum-ultraviolet fluorescence spectra of KY3F10:Nd3+ (KYF:Nd) and YF3:Nd3+ (YF:Nd) single crystals pumped by a pulsed-discharge molecular F2 laser at 157 nm were obtained. A number of new fluorescence peaks were observed and were assigned to the 4f25d → 4f3 dipole-allowed transitions of the Nd3+ ion. The absorption spectra of LiYF4:Nd3+ (YLF:Nd), KYF:Nd, and YF:Nd crystal samples in the vacuum-ultraviolet spectral regions were also obtained. Finally, the splitting of the states of the 4f25d configuration of the Nd3+ ion, which is due to the crystal field, was observed in all the crystal samples.

Subnanosecond Tunable Ultraviolet Pulse Generation from a Low-Q, Short-Cavity Ce:LiCAF Laser

We have developed an all-solid-state tunable ultraviolet laser system employing recently developed Ce:LiCAF, a new degradation-free tunable ultraviolet laser medium pumped by the fourth harmonic of a conventional Q-switched Nd:YAG laser. The low-Q, short-cavity Ce:LiCAF laser produced satellite-free subnanosecond pulses in a tuning range of 281 nm to 297 nm under appropriate pumping-fluence control.

Ultraviolet subnanosecond pulse train generation from an all‐solid‐state Ce:LiCAF laser

We have directly and passively generated a 290‐nm, 600‐ps pulse train from a Ce:LiCAF laser pumped by the fourth harmonic of a conventional 10‐ns Q‐switched Nd:YAG laser. This simple, all‐solid‐state, short‐pulse laser has been realized by employing a recently studied, self‐injection‐seeding pulse‐train generation scheme using Ce:LiCAF, a tunable ultraviolet laser medium.