Growth, Mechanical, Thermal and Spectral Properties of Cr3+∶MgMoO4 Crystal

This paper reports the growth, mechanical, thermal and spectral properties of Cr3+∶MgMoO4 crystals. The Cr3+∶MgMoO4 crystals with dimensions up to 30 mm×18 mm×14 mm were obtained by TSSG method. The absorption cross-sections of 4A2→4T1 and 4A2→4T2 transitions are 12.94×10−20 cm2 at 493 nm and 7.89×10−20 cm2 at 705 nm for E//Ng, respectively. The Cr3+∶MgMoO4 crystal shows broad band emission extending from 750 nm to 1300 nm with peak at about 705 nm. The emission cross-section with FWHM of 188 nm is 119.88×10−20 cm2 at 963 nm for E//Ng. The investigated results showed that the Cr3+∶MgMoO4 crystal may be regarded as a potential tunable laser gain medium

Thermal, Spectral and Laser Properties of Er3+:Yb3+:GdMgB5O10: A New Crystal for 1.5 μm Lasers

A novel laser crystal of Er3+:Yb3+:GdMgB5O10 with dimension of 26 × 16 × 12 mm3 was grown successfully from K2Mo3O10 flux by the top seeded solution growth method. The thermal diffusivity and specific heat capacity were measured to calculate the thermal conductivity of the crystal. The absorption and fluorescence properties of the crystal at room temperature were investigated in detail. The Judd-Ofelt method was used to analyze the polarized absorption spectra. The emission cross-section of the 4I13/2→4I15/2 transition was calculated by the Füchtbauer-Ladenburg formula and the relevant gain cross-sections were estimated. Continuous-wave laser output of 140 mW at 1569 nm with the slope efficiency of 17.8% was demonstrated in a plano-concave resonator. The results reveal that Er3+:Yb3+:GdMgB5O10 crystal is a promising material for 1.5 μm lasers

Optical study of Cr3+-doped LaSc3(BO3)(4) crystal

This paper reports on the optical properties of Cr3+-doped LaSc3(BO3)(4) (Cr3+:LSB). Based on measurement of the absorption spectrum the crystal field strength Dq, the Racah parameters B and C were calculated. The photoluminescence spectrum of Cr3+:LSB via T-4(2) -->(4)A(2) transition is a broadband emission from 740 to 1280 nm at room temperature. The measurements of absorption and photoluminescence spectra show that in Cr3+:LSB the Cr3+ ions occupy weak crystal field sites

Crystal growth and optical assessment of Nd3+ : GdAl3(BO3)4 crystal

This paper reports the high-temperature top-seeded solution growth (TSSG) of large single crystal of Nd3+-doped GdAl3(BO3)4 from a K2Mo3O10-LiF flux cooled at a rate of 2 K/day and using a crystal rotation rate of 4.5 rpm. Thepolarized optical absorption and fluorescence spectra of Nd3+ : GdAl3(BO3)4 crystal have been investigated. Polarized absorption cross sections are 4.3x10-20 and 2.6x10-20 cm2 with band widths of 8.7 and 6.1 nm for σ- and π-polarization, respectively. The emission cross sections are 6.3x10-19 and 6.0x10-19 cm2 for σ- and π-polarization, respectively, at 1062 nm corresponding to the 4F3/2→4I11/2 transition. The fluorescence lifetime is 54.3 and 57 μs at 300 and 20 K, respectively

Continuous-wave and SESAM mode-locked femtosecond operation of a Yb:MgWO4laser

We present a detailed continuous-wave regime characterization and, for the first time to the best of our knowledge, SESAM mode-locked femtosecond operation with a monoclinic, Yb3+-doped, MgWO4 crystal. Pumping with a low-power, single-mode fiber-coupled laser diode emitting at 976 nm, we demonstrate threshold for continuous-wave (cw) operation as low as 50 mW (absorbed pump power) and slope efficiency up to ~60% (with respect to the absorbed pump power) for two of the principal emission polarizations. The output wavelength in the cw regime is continuously tunable over a ∼50 nm broad range. Mode-locking the laser with a SESAM, we achieve almost Fourier-transform limited pulses with a duration of 132 and 125 fs depending on the polarization

SESAM mode-locked Yb:GdYCOB femtosecond laser

We report a detailed characterization of the diode-pumping operation of the mixed crystal Yb0.1:Gd0.5Y0.4COB, including cw, tunable and femtosecond laser regimes. This crystal was recently proposed as a promising candidate for high-power as well as femtosecond operation. Our results show that the crystal quality and performance is comparable to the more deeply investigated and closely related calcium yttrium oxoborate and calcium gadolinium oxoborate laser crystals