Nd³⁺-Doped La₂CaB₈O₁₆ Crystals for Orthogonally Polarized Dual-Wavelength Near-Infrared Lasers

Abstract

The Nd3+-based laser crystal is one of the key gain media for all-solid-state laser technology. Herein, by investigating the relationship between structure and optical properties, we found that a La-containing borate, La2CaB8O16, with a long rare-earth ion distance more than 4.27 Å, allows a high doping concentration and exhibits a weak fluorescence quenching effect. For the first time, Nd3+-doped La2CaB8O16 crystals with different concentrations were grown by the top seeded solution growth method with large size and high optical quality. Its spectral characters were measured, suggesting a strong absorption band at 800 nm and a fluorescence band at 1055 nm. Furthermore, a diode-pumped orthogonally polarized dual-wavelength laser operation at 1052 and 1055 nm was realized, with a slope efficiency of 16.3% and output power of 859 mW. These results suggest that the Nd3+-doped La2CaB8O16 crystal is a promising laser gain medium for 1 μm lasers and possible generation of terahertz radiation.

Preparation and Optical Properties of Nd:Bi2Ti2O7 Laser Crystal with Disordered Structure and Attractive Multiwavelength Emission Characteristics

“…The spectral parameters of the Nd:BTO crystal are compared with those of other Nd-doped laser crystals, and the results are shown in Table S7 (SI). It was found that the absorption cross section and emission cross section of the Nd:BTO crystal are both larger than that of Nd:LCB crystal (realized dual-wavelength laser output at 1052, 1055 nm) and Nd:β-LBS crystal (realized triple-wavelength laser output at 1047, 1071, 1092 nm), 35,62 indicating that Nd:BTO is a promising multiwavelength laser crystal serving as potential light sources used in terahertz radiation. The gain cross section σ g can be derived using the formula 16…”

“…Among the known oxide crystals, the crystals with an infrared cutoff edge of more than 6 μm are rare, which may be one of the reasons that the crystals used in mid-IR laser are basically metal chalcogenides rather than oxide Table presents a summary of the optical transmittance ranges for various common oxide crystals. ,− It can be seen from the table that the infrared cutoff edge of the BTO crystal was larger than some common oxide crystals, such as Y 3 Al 5 O 12 , YBa 3 (PO 4 ) 3 , LiNbO 3 , La 3 Ga 5 SiO 14 , and so forth, indicating that the BTO crystal has potential for near-mid-IR optical applications.…”

LGYSB:Nd─High-Performance Lasing in the Near-Infrared Region

“…In the last years, several Nd-doped borate crystals like Nd-doped La 2 CaB 8 O 16 , Nd-doped GdMgB 5 O 10 (GMB:Nd), Nd-doped YMgB 5 O 10 (YMB:Nd), and Nd-doped LaBSiO 5 (β-LBSO) were grown by the flux method as promising laser media emitting in the 1 μm wavelength region. The Nd-doped La 2 CaB 8 O 16 crystal generated laser emission with a slope efficiency of 16.3% at 1052 and 1055 nm, while the YMB:Nd crystal operated at 1054 and 1090 nm with a slope efficiency of 31.9% . The Nd-doped LaBSiO 5 (high-temperature phase β-LBSO) is a good candidate to produce triple-wavelength lasers at 1047, 1071, and 1092 nm; however, the crystal growth is challenging because of the phase transition from β-LBSO to the low-temperature phase (α-LBSO) at 162 °C …”

“…% LSB:Nd crystal, laser emission at 1.06 μm was reported under laser diode pumping at 807 nm with a slope efficiency of 55% . In the last years, several Nd-doped borate crystals like Nd-doped La 2 CaB 8 O 16 , Nd-doped GdMgB 5 O 10 (GMB:Nd), Nd-doped YMgB 5 O 10 (YMB:Nd), and Nd-doped LaBSiO 5 (β-LBSO) were grown by the flux method as promising laser media emitting in the 1 μm wavelength region. The Nd-doped La 2 CaB 8 O 16 crystal generated laser emission with a slope efficiency of 16.3% at 1052 and 1055 nm, while the YMB:Nd crystal operated at 1054 and 1090 nm with a slope efficiency of 31.9% .…”

A Modified Method for Determining the Optical Indicatrix in Monoclinic Crystals Based on Optical Prisms

“…Optical crystal is one the most important optical materials widely used in scientific research, military, and civilian applications. − In recent several decades, multitudes of new compounds have been designed and synthesized for obtaining advanced nonlinear optical (NLO) crystals, birefringent crystals, and laser crystals, aiming at advances in optical technologies. − Among them, quite a few compounds crystallize in a low-symmetrical monoclinic system . Generally, identifying the directions of orthogonal principal optical indicatrix axes is a precondition for the applications of optical crystals, which can be achieved precisely by the minimum deviation method based on optical prisms.…”