一种新型掺铒碲酸盐玻璃的光谱性质研究

研究了一种新型掺Er^3+碲酸盐玻璃的光谱性质；应用Judd-Ofelt理论计算了碲酸盐玻璃中Er^3+离子的强度参数Ω(Ω2=4．79×10^-20cm^2，Ω4=1．52×10^-20cm^2，Ω6=0．66×10^-20cm^2)，计算了离子的自发跃迁概率，荧光分支比；应用McCumber理论计算了Er^3+的受激发射截面(σe=10．40×10^-21cm^2)，Er^3+离子^4I13/2→^4I15/2发射谱的荧光半高宽(FWHM=65．5nm)及各能级的荧光寿命(^4I13/2能级为τrad

Effects of melting temperature on the broadband infrared luminescence of bi-doped and Bi/Dy co-doped chalcohalide glasses

Bismuth (Bi)-doped and Bi/Dy co-doped chalcohalide glasses are investigated as promising materials for amplifiers in optical communication. The samples synthesized at lower melting temperatures (MTs) are characterized by more intensified infrared emissions. With respect to the redox process of a liquid mixture at different MTs, we attribute an emission at 1230 nm to low-valent Bi ions. The lower MT favors the formation of LVB ions, i.e. Bi+ or Bi2+, while the higher MT promotes the production of higher-valent Bi ions Bi3+. An enhanced broadband infrared luminescence with the full-width at half-maximum over 200 nm is achieved from the present Bi/Dy co-doped chalcohalide glasses.

Transparent Ni2+-doped lithium-alumino-silicate glass-ceramics for broadband near-infrared light source

Broadband infrared luminescence centred at around 1300 nm with full-width at half maximum of about 342 nm was observed from transparent Ni2+-doped lithium-alumino-silicate glass-ceramics embedded with beta-eucryptite crystallines. The room temperature fluorescent lifetime was 98 mu s. The transparent glass-ceramics may have potential applications in a widely tunable laser and a super-broadband optical amplifier for optical communications.

Bismuth-doped zinc aluminosilicate glasses and glass-ceramics with ultra-broadband infrared luminescence

Broadband infrared luminescence covering the optical telecommunication wavelength region of 0, E and S bands was observed from bismuth-doped zinc aluminosilicate glasses and glass-ceramics. The spectroscopic properties of the glasses and glass-ceramics depend on the thermal-treatment history. With the appearance of gahnite (ZnAl2O4) crystalline phase, the fluorescent peak moves to longer wavelength, but the fluorescent intensity decreases. The similar to 1300 nm fluorescence with a FWHM larger than 250 nm and a lifetime longer than 600 mu s possesses these optical materials with potential applications in laser devices and broadband amplifiers. The broad infrared luminescence from the bismuth-doped zinc aluminosilicate glasses and glass-ceramics might be from BiO or bismuth clusters rather than from Bi5+ and Bi3+. (c) 2005 Elsevier B.V. All rights reserved.

Transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence

We report on transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni2+-doped MgO-Al2O3-SiO2 glass is Prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315nm with full width at half maximum (FWHM) of about 300nm is observed from the glass ceramics. The observed infrared emission could be attributed to the T-3(2g)(F-3) -> (3)A(2g)(F-3) transition of octahedral Ni2+ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6 X 10(-24) s cm(2).

CW-pumped evanescent amplification based on side-polished fiber with heavily Er3+-doped glass overlay

A novel diffractive-pumping scheme is proposed to improve the evanescent amplification using blazed fiber grating for the first time. We also investigate the cw-pumped-evanescent amplification at 1.55 mu m wavelength with the relative optical gain pumped at 1480 nm of around 2 dB based on side-polished fiber with the effective interaction length as long as 16 mm and with a heavily Er3+-doped (N-Er(3+) > 1.19 x 10(21) ions/cm(3)), low refractive index (n(1550) < 1.47) glass overlay, which has no concentration quenching (tau(f) = 9.0 ms).

Effect of various alkaline-earth metal oxides on the broadband infrared luminescence from bismuth-doped silicate glasses

We report on the effect of various alkaline-earth metal oxides on the broadband infrared luminescence covering 1000-1600 nm wavelength region from bismuth-doped silicate glasses. The full width at half maximum (FWHM) of the infrared luminescence and the fluorescent lifetime is more than 200 nm and 400 mu s, respectively. The fluorescent intensity decreases with increasing basicity of host glasses. Besides the broadband infrared luminescence, luminescence centered at 640 nm was also observed, which should be ascribed to Bi2+ rather than to the familiar Bi3+. We suggest that the infrared luminescence should be assigned to the X-2 (2)Pi (3/2) -> X-1 (2)Pi(1/2) transition of BiO molecules dispersed in the host glasses. (c) 2006 Elsevier Ltd. All rights reserved.

Spectroscopic properties of Er3+ doped TeO2-BaO (Li2O, Na2O)-La2O3 glasses for 1.5-mu m optical amplifiers

This paper reports on the optical spectroscopic properties and thermal stability of Er3+-doped TeO2-BaO (Li2O,NaO)-La2O3 glasses for developing 1.5-mu m fiber amplifiers. Upon excitation at 977 nm laser diode, an intense 1.53-mu m infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 60 nm for the Er3+-doped TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO. The calculated fluorescence lifetime and the emission cross-sections of the 1.53-mu m transition are 2.91 ms and similar to 9.97 x 10(-21) cm(2), respectively. It is noted that the gain bandwidth, a, x FWHM, of the TeO2-BaO-La2O3Er2O3 glass is about 600, which is significantly higher than that in silicate and phosphate glasses. Meanwhile, it is interesting to note that the TeO2-BaO-La2O3-Er2O3 glass has shown a high glass thermal stability and good infrared transmittance. As a result, TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO has been considered to be more useful as a host for broadband optical fiber amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Broadband near-infrared emission in Er3+-Tm3+ codoped chalcohalide glasses

The near-IR emission spectra of Er3+-Tm3+ codoped 70GeS(2)-20In(2)S(3)-10CsI chalcohalide glasses were studied with an 808 nm laser as an excitation source. A broad emission extending from 1.35 to 1.7 mu m with a FWHM of similar to 160 nm was recorded in a 0.1 mol.% Er2S3, 0.5 mol.% Tm2S3 codoped chalcohalide glass. The fluorescence decay curves of glasses were measured by monitoring the emissions of Tm3+ at 1460 nm and Er3+ at 1540 nm, and the lifetimes were obtained from the first-order exponential fit. The luminescence mechanism and the possible energy-transfer processes are discussed with respect to the energy-level diagram of Er3+ and Tm3+ ions. (C) 2008 Optical Society of America

Effects of thermal treatment on broadband near-infrared emission from Bi-doped chalcohalide glasses

GeGaSKBr glass with Bi ions as emission centers were fabricated. An intense emission centered at around 1230 nm with the width of more than 175 nm was observed by 808 nm photo-excitation of the glass. Lower quenching rate and thermal treatment promote micro-crystallization process, thus strengthening the emission. Crown Copyright (c) 2008 Published by Elsevier Ltd. All rights reserved.

Enhanced broadband near-infrared luminescence from transparent Yb 3+/Ni2+ codoped silicate glass ceramics

The near-infrared emission intensity of Ni2+ in Yb3+/Ni2+ codoped transparent MgO-Al2O3-Ga2O3-SiO2-TiO2 glass ceramics could be enhanced up to 4.4 times via energy transfer from Yb3+ to Ni2+ in nanocrystals. The best Yb2O3 concentration was about 1.00 mol%. For the Yb3+/Ni2+ codoped glass ceramic with 1.00 mol% Yb2O3, a broadband near-infrared emission centered at 1265 nm with full width at half maximum of about 300 nm and lifetime of about 220 mu s was observed. The energy transfer mechanism was also discussed. (C) 2008 Optical Society of America.

Inhomogeneous broadening, luminescence origin and optical amplification in bismuth-doped glass

Absorption and luminescence spectra and optical amplification in bismuth-doped germanate silicate glass were investigated. Two kinds of bismuth ion valence states could exist in the glass. One is Bi2+, which has shown red luminescence, another might be Bi+, which is the active center for infrared luminescence. The infrared luminescence excited at 700, 800, and 980 nm should be ascribed to the electronic transition P-3(1) --> P-3(0) of Bi+ ions in three distinct sites. The shifting, broadening, and multiple configuration of the luminescence could be due to the randomly disorder of local environment and multiple sites of the active centers. In this glass, obvious optical amplification was realized at 1300 nm wavelength when excited at 808 and 980 nm, respectively.

Transparent Ni2+-doped silicate glass ceramics for broadband near-infrared emission

Transparent Ni2+-doped MgO-Al2O3-Ga2O3-SiO2-TiO2 glass ceramics were fabricated. The precipitated nanocrystal phase in the glass ceramics was identified by X-ray diffraction and transmission electron microscope. Broadband near-infrared emission centered at 1220 nm with full width at half maximum of about 240 nm and lifetime of about 250 mu s was observed with 980 nm excitation. The longer wavelength emission compared with Ni2+-doped MgAl2O4 crystal was attributed to the low crystal field occupied by Ni2+ in the glass ceramics. The present Ni2+-doped transparent glass ceramics may have potential applications in broadband optical amplifiers. (c) 2007 Elsevier B.V. All rights reserved.

Bismuth-activated luminescent materials for broadband optical amplifier in WDM system

New broadband near infrared luminescence covering the whole work windows (1260-1625 nm) of the current wavelength division multiplexing (WDM) system was found from bismuth-activated M2O-Al2O3-SiO2 (M = Li, Na) and Li2O-Ta2O5-SiO2 glasses at room temperature in the case of 808 nm-laser excitation. But the near infrared luminescence mechanism of the bismuth-activated glasses is not well understood up to now. The figure-of-merits of bandwidth and gain of the glasses are better than those of Er3+-doped silicate glasses and Ti3+ doped sapphire, implying they are the promising gain-medium candidates for the broadband amplifiers and the widely tunable laser sources. (c) 2007 Elsevier B.V. All rights reserved.

Broadband infrared luminescence from bismuth-doped GeS2-Ga2S3 chalcogenide glasses

Near-infrared luminescence is observed from bismuth-doped GeS2-Ga2S3 chalcogenide glasses excited by an 808 nm laser diode. The emission peak with a maximum at about 1260 nm is observed in 80GeS(2)-20Ga(2)S(3):0.5Bi glass and it shifts toward the long wavelength with the addition of Bi gradually. The full width of half maximum (FWHM) is about 200 nm. The broadband infrared luminescence of Bi-doped GeS2-Ga2S3 chalcogenide glasses may be predominantly originated from the low valence state of Bi, such as Bi+. Raman scattering is also conducted to clarify the structure of glasses. These Bi-doped GeS2-Ga2S3 chalcogenide glasses can be applied potentially in novel broadband optical fibre amplifiers and broadly tunable laser in optical communication system.