Progress in Nd³⁺, Er³⁺, and Yb³⁺ doped laser glasses at Shanghai Institute of Optics and Fine Mechanics

Abstract

This paper reviews the progress made on Nd3+, Er3+, and Yb3+ doped laser glasses at SIOM, China. Key properties of Nd: phosphate and Nd: fluorophosphate (FP) laser glasses are presented and compared with the commercial laser glasses from Hoya and Schott. Also reviewed are properties of four types of Er: phosphate glasses. The development of a continuous, large‐scale melting platform producing high‐quality Nd: phosphate laser glass at SIOM is briefly described. Our study on the Stark splitting of Yb3+: 2F7/2 level indicates that mixed‐glass formers can significantly improve the Stark splitting, resulting enhancement of lasing performance of Yb: phosphate glass.

Optical properties of Er3+ and Yb3+/Er3+‐doped NaF‐Na2SO4‐Al(PO3)3 fluoro‐sulfo‐phosphate glasses

“…The density of samples was tested through Archimedes method at room temperature, using alcohol as the immersion liquid. The precision in the measurement was ±0.005 g/cm 3 . The refractive index was measured by a prism coupler instrument (Metricon Model 2010M, American).…”

“…Phosphate glass has been an attractive matrix for laser oscillators and amplifiers due to its good spectroscopic properties, high solubility to rare earth (RE) ions, large damage threshold and accessible production with large size 1,2 . The addition of fluoride to phosphate could produce the famous fluoro‐phosphate (FP) glass characterized by low linear (1.4‐1.5) and nonlinear refractive indexes (2.05‐2.14 × 10 −20 m 2 /W), high optical transmittance in pump and infrared spectral range (0.28‐4 μm), high RE ions solubility (10 21 ions/cm 3 ), and tailorable spectroscopic properties, whereas minor emission cross‐section and higher thermal expansion coefficient (138‐165 × 10 −7 /°C) than phosphate glasses 3,4 …”

“…1,2 The addition of fluoride to phosphate could produce the famous fluoro-phosphate (FP) glass characterized by low linear (1.4-1.5) and nonlinear refractive indexes (2.05-2.14 × 10 −20 m 2 / W), high optical transmittance in pump and infrared spectral range (0.28-4 μm), high RE ions solubility (10 21 ions/cm 3 ), and tailorable spectroscopic properties, whereas minor emission cross-section and higher thermal expansion coefficient (138-165 × 10 −7 /°C) than phosphate glasses. 3,4 The further modification of FP glass has been considered to achieve better properties. Kumar et al 5,6 studied the effect of sulfate and borate additions on the optical properties of RE 3+ ions in FP glasses, stating that sulfate acts positively on the stimulated emission cross-section and luminescence efficiency.…”

Engineering of semiconductor nanocrystals and metal Ions in amorphous materials

“…Nevertheless, a positive internal gain is possible even for very small pump power, which allows that a very low threshold can be achieved. Recently, three Nd:phosphate laser glasses, LHG-8 (Hoya), LG-770 (Schott), and N31 (Shanghai Institute of Optics and Fine Mechanics, SIOM), have been developed for high power laser inertial confinement fusion (ICF) technology demonstration and application and are currently used by National Ignition Facility (NIF) in the United States, Laser Megajoule (LMJ) in France, and Shen Guang in China, respectively [7].…”

“…The large stimulated emission cross-section of emitting transitions are favorable level compared with that of the other materials, the high stimulated emission and optical gain/bandwidths are unique among Nd 3+ doped glasses. In addition, we have compared lasing wavelength (λ), effective linewidth (∆λ ef f ) and stimulated emission cross-section (σ p (λ)) of our glasses with reported commercial phosphate glasses [7], as shown in Figure 5.22. It can be seen that our glasses also provide better lasing properties, especially higher emission intensity of x = 20 mol% TeO 2 sample (see Figure 5.20(a)) which is expected to perform better lasing operation at 1.06 µm with low threshold power.…”