Nd³⁺ Cluster Adjustment in Nd³⁺:CaNb₂O₆ by Codoping La³⁺ Buffers for Improvement of Fundamental and Self-Stimulated Raman Scattering Laser Operation: A Study Case from the Perspective of Defect Chemistry

Abstract

The fluorescence quenching caused by Nd3+ clusters in Nd3+-doped crystals even at low Nd3+ concentration has restrained the performance of Nd3+ lasers. In this work, Nd3+:CaNb2O6 and Nd3+:La3+:CaNb2O6 single crystals have been grown by the Czochralski method. RE3+ (RE3+ = Nd3+, La3+) ion incorporation mechanisms, the formation of Nd3+ clusters, and the feasibility of La3+ ions as buffers in RE3+:CaNb2O6 crystals have been demonstrated and assessed by atomistic simulation methods. The spectral and laser properties of Nd3+:CaNb2O6 and Nd3+:La3+:CaNb2O6 have been measured. All of the results indicate the Nd3+ dimers with distances between Nd3+ close to the critical interaction distance have formed in Nd3+:CaNb2O6 and the La3+ ions as buffers can alleviate the interaction of Nd3+ effectively in the Nd3+:La3+:CaNb2O6 as expected. Benefiting from the introduction of La3+ buffers, about 2.6 W fundamental laser with a slope efficiency of 36.5% and about a 310 mW self-stimulated Raman scattering laser with conversion and slope efficiencies of 8.3% and 9.5%, respectively, which are superior to those of Nd3+:CaNb2O6, have been achieved in Nd3+:La3+:CaNb2O6.

The Electronic, Structural, and Optical Properties of CaNb2O6 Compound: Theoretical Study

“…Having an orthorhombic crystal structure with Pbcn space group, [ 1 ] Calcium niobate (CaNb 2 O 6 , hereafter CNO) has attracted considerable attention of researchers due to being a strong source of coherent light which makes it a perfect candidate for various applications such as catalysis, optoelectronics, laser technology, luminescent technology, and optical thermometer. [ 2–6 ]…”

Passively Q-Switched KTA Cascaded Raman Laser with 234 and 671 cm−1 Shifts

“…Moreover, KTA has also attracted increasing attention due to its potential application for efficient stimulated Raman laser operation [5][6][7]. As an effective way to generate coherent light with new wavelengths, stimulated Raman scattering (SRS) has merits for preparing simple, compact, and robust laser sources [8][9][10]. Diverse crystals have been adopted for efficient Raman lasers, such as vanadates [11][12][13], tungstates [14][15][16][17], and molybdates [18].…”