In order to develop efficient visible upconversion lasers and optical fiber amplifiers, the detailed spectroscopic
properties of singly doped Er3+ and codoped Er3+-Yb3+ ions in lead tungsten tellurite (LTT) glasses have been
investigated. The glasses were prepared by the conventional melt quenching technique. Absorption, visible upconversion
spectra and NIR emission spectra were recorded as a function of Yb3+ ions concentrations. Judd-Ofelt (J-O) analysis has
been performed for the spectral intensities of Er3+and Er3+-Yb3+
absorption bands. Spontaneous emission probabilities
(AR), radiative lifetimes (τR) and branching ratios (βR) were calculated by using the phenomenological Judd-Ofelt
intensity parameters. Three strong upconversion emission bands centered at 526, 551 and 665 nm were observed under
980nm excitation, due to the energy transfer process from Yb3+ to Er3+ ions. The green emissions centered at 526 and
551 nm and the red emission at 665 nm are attributed to 2H11/2→ 4I15/2, 4S3/2→ 4I15/2 and 4F11/2→ 4I15/2 transitions of
Er3+ions respectively. The relative intensity variations of 2H11/2→ 4I15/2, 4S3/2→ 4I15/2 and 4F9/2→ 4I15/2 transitions have
been explained on the basis of the increase in the population accumulation rates of 2H11/2 ,4F9/2 and 4S3/2 levels. The peak
stimulated emission cross-section (σe) and gain bandwidth parameter (σe×▵λeff) of 4I13/2 → 4I15/2 transition at 1.54 μm for Er3+ and Er3+-Yb3+ ions in LTT glasses have been determined and compared with different glass hosts. The stimulated emission cross-sections (σe) determined by using McCumber theory for the 4I13/2 → 4I15/2 transition are compared with
the measured (σe) values obtained from the emission data. The results of these investigations revealed that the lead
tungsten tellurite (LTT) glasses could be more useful as promising host materials for the design and development of
optical fiber amplifiers and upconversion lasers.
Calcium fluoroborate (CFB) glasses doped with different concentrations of Tb3+ ions have been prepared with
molar composition of (42-x) B2O3 + 20 CaF2 +15 CaO + 15 BaO + 8 Al2O3 + x TbF3 (x=0.05, 0.1, 0.5, 1.0, 2.0 and 4.0)
by melt quenching method. Optical absorption spectrum for 1.0 mol% of Tb3+:CFB glass was recorded in UV-Vis-NIR
regions. Radiative parameters such as radiative transition probabilities (AR), radiative lifetimes (τR), radiative branching
ratios (βR) for the 5D3 and 5D4 excited states have been calculated by using the Judd-Ofelt parameters (Ωλ=2,4,6). The
luminescence spectra recorded for different concentrations of Tb3+ ions in CFB glasses exhibit seven and four bands
originating from 5D4 and 5D3 excited states respectively. As the concentration of Tb3+ ions increases the intensities of
luminescence peaks originating from 5D4 state increases, whereas, the quenching of intensities has been observed for the
emission peaks originating from 5D3 state due to energy transfer through cross-relaxation channel (5D3 : 7F6) → (5D4 :
7F0).
The experimental lifetimes of 5D4 state for all the concentrations of Tb3+ ions are equal and exhibit single exponential
decay with highest quantum efficiency which confirms that these glasses can be used for high intensity green emission
even at high concentrations of Tb3+ ions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.