Structural and spectral characterization of novel non-centrosymmetric 2,4-dintrobenzene derivative.

A novel organic compound 9-(2,4-dinitrophenyloxy)-3,3,8-trimethyl-1,5-dihydro-[1,3]dioxepino[5,6-c]pyridine (DNPAP) has been synthesized and a nonlinear optical (NLO) crystal has been grown by slow evaporation method. Compound was subjected to different characterization analyses in order to find out its suitability for optoelectronic applications. Single crystal and powder X-ray diffraction analyses show that DNPAP crystallizes in the orthorhombic space group Pca21. The range of optical absorption was ascertained by recording UV­Vis spectrum. The second harmonic generation (SHG) test has shown that DNPAP possesses 6.4-times higher NLO efficiency compared to KDP.

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(3+):LuLiF(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.

Direct and passive subnanosecond pulse-train generation from a self-injection-seeded ultraviolet solid-state laser.

We propose a passive self-injection-seeding scheme for the generation of short-pulse trains from various pulsed lasers. In this scheme a single subnanosecond pulse is generated from a short-cavity seeding laser. The pulse is then returned to the same gain medium and amplified regeneratively until the gain is quenched completely. Cw operation capability or an external short-pulse seeding laser is not required for generation of short-pulse trains. Based on this simple scheme an ultraviolet subnanosecond pulse train is directly and passively generated from a solid-state laser medium (Ce(3+):LuLiF(4)) pumped by a standard 10-ns laser.

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).

Spectroscopy and stimulated emission of Nd(3+) in an acentric CsY(2)F(7) host.

The results of preliminary spectroscopic studies of new fluoride single-crystal CsY(2)F(7) that is activated by Nd(3+) ions are given. Direct evidence for the possibility of application of this ordered material as a laser host is given for the first time to our knowledge. Stimulated emission of Nd(3+) ions on the main intermultiplet transition is obtained under both nonselective flash-lamp pumping conditions and continuous Ar ion laser pumping conditions.