Virtual Journal of Laser

Example of a color image (taken with a hand-held CCD-photocamera Samsung WB 500) of the spatially distributed conical components of parametric multi-wavelength anti-Stokes RFWM lasing (“anti-Stokes laser rainbow”) of an aragonite single crystal recorded at room temperature under picosecond pumping at λ_f1 = 1.06415 µm wavelength in excitation geometry e₃[e₁e₁]e₃ (Cover picture: A.A. Kaminskii, H. Rhee, et al. pp. 259–284, in this issue) (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

In our fiber-format NV-center light sources (Cover Picture), a photoniccrystal fiber is infiltrated with a syringe-pressurized fluid containing NV-diamond nanoparticles (ND) with a mean diameter of 300 nm. The NV centers impregnate the fiber as a result of this procedure, filling the air holes along the entire fiber length. Experiments were performed with a total number of diamond nanoparticles of approximately 10³ per 1 cm of the fiber. The 532-nm, 100-mW second-harmonic output of a diode-pumped continuous-wave Nd:YAG laser was used as a source of optical pump. (Cover picture: I.V. Fedotov, N.A. Safronov, et al. pp. 151–154, in this issue) (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

The characterization of new gain-switched Fe:Cr:Zn_1–xMg_xSe laser working at the room temperature and its comparison to Fe:ZnSe laser was performed. The laser oscillation behavior, generation efficiency and output wavelength tuning possibilities were demonstrated. It was shown that the absorption and luminescence spectra of Fe:Cr:ZnMgSe crystal are shifted towards longer wavelengths in comparison with Fe:ZnSe active material. The difference is approximately 300 nm and it corresponds to measured absorption and emission spectra. The maximal Fe:Cr:ZnMgSe laser generated energy and the slope efficiency with respect to the absorbed energy were 200 µJ and 4.5%, respectively. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

Multiple Stokes and anti-Stokes χ⁽³⁾-nonlinear generation in the tetragonal crystal of CaYAlO₄ was observed at 300K and ≈9K under picosecond excitation in the visible spectral range. All the recorded Raman induced laser lines were identified and attributed to the SRS-promoting vibration mode of octahedral [AlO₆]^–9 units of the crystal. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

Intra-cavity frequency doubling of continuous-wave (CW) laser emission on the quasi-three level (⁴F_3/2 → ⁴I_9/2) laser transition of Nd³⁺ in Nd:GGG is reported by using a three-mirror folded resonator. The thermal lens experienced by the optically-pumped Nd:GGG laser crystal is measured as a function of the absorbed pump power and compared to that found, in the same conditions, in the case of Nd:YAG. Results are interpreted by using a simple model accounting for the absorbed pump power and the thermo-mechanical properties of each laser crystal. Diode-pumped blue laser operation is achieved, for the first time, at 467.0 and 468.5 nm with output powers of 230 and 450 mW, respectively. Simultaneous laser operation resulting both from frequency-doubling and frequency summing at the three 467.1, 467.7, and 468.1 nm laser wavelengths is also obtained with a total output power of 60 mW. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

In this work it is shown, that laser with injection of reflected radiation can possess the high longitudinal spatial selectivity. Laser figures here both the emitter and the detector of radiation. This attribute, having volumetric character for laser fields, can be considered as a new modality in optical microscopy. Using the experimental possibilities we achieved the spatial resolution at a level of several microns. The optimization of laser sources is to lead to longitudinal spatial resolution at a level of nanometers. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

A compact diode-pumped solid-state Tm:KY(WO₄)₂ laser with cavity length of 1 cm passively Q-switched with a PbS-quantum-dot-based saturable absorber is presented. The laser operates at the wavelength of 1.94 µm and produces pulses with duration of 8 ns and energy of 30 µJ at the repetition rate up to 4.2 kHz. The maximum output power of 120 mW is achieved at incident pump power of 1.15 W. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

Spectroscopic properties and continuous-wave laser performance of a new Yb_0.015:Lu_0.162Gd_0.823VO₄ mixed vanadate crystal are reported. An appreciable discontinuous increase in output power occurs during the σ - to π -polarization switching process in the laser oscillation. A maximum output power of 4.3 W is generated with an optical-to-optical efficiency of 46%, whereas the average slope efficiency is determined to be 73–77%, depending on the output coupling utilized. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

The present work gives a brief review of the nonlinear χ⁽²⁾- and χ⁽³⁾-lasing properties of SRS-active natural crystals (minerals) known so far. This compilation complements new results of a detailed investigation of Raman induced χ⁽³⁾-effects in aragonite single crystals (orthorhombic CaCO₃) under single- and dual-wavelength picosecond excitation in the UV, visible and near-IR spectral ranges. The studied effects at room and cryogenic temperatures comprise Stokes and anti-Stokes combs of almost two octaves bandwidth, THG, SFG, as well as cascaded and cross-cascaded χ⁽³⁾ ↔ χ⁽³⁾ interactions.

We propose a new scheme of attosecond pulse generation by starting from a narrow-band transform-limited high-power solid-state laser and phase lock the fundamental and its first four cascaded harmonics generated by the second-order nonlinear optical processes. The relative phase among the optical fields of the harmonics can be maintained a constant at least for thousands of nanosecond pulses. The worst-case relative phase fluctuation is 0.04π rad. It is shown that sub-single-cycle (∼0.37 cycle) sub-femtosecond (360 attosecond) pulses with carrier-envelope phase (CEP) control can be generated in this manner. The peak intensity of each pulse exceeds 10¹⁴ W/cm² when it is focused to a spot size of 20 µm. We also demonstrate synthesis of square and saw-tooth waveforms. (© 2011 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)