Title :
Energy recycling versus lifetime quenching in erbium-doped 3-μm fiber lasers
Author :
Pollnau, Markus ; Jackson, Stuart D.
Author_Institution :
Inst. of Appl. Opt., Swiss Fed. Inst. of Technol., Lausanne, Switzerland
fDate :
2/1/2002 12:00:00 AM
Abstract :
Based on recently published spectroscopic measurements of the relevant energy-transfer parameters, we performed a detailed analysis of the population mechanisms and the characteristics of the output from Er 3+-singly-doped and Er3+, Pr3+-codoped ZBLAN fiber lasers operating at 3 μm, for various Er3+ concentrations and pump powers. Whereas both approaches resulted in similar laser performance at Er3+ concentrations <4 mol.% and pump powers <10 W absorbed, it is theoretically shown here that the Er3+-singly-doped system will be advantageous for higher Er3+ concentrations and pump powers. In this case, energy recycling by energy-transfer upconversion from the lower to the upper laser level can increase the slope efficiency to values greater than the Stokes efficiency, as is associated with a number of Er3+-doped crystal lasers. Output powers at 3 μm on the order of 10 W are predicted
Keywords :
absorption coefficients; erbium; fibre lasers; infrared spectra; laser transitions; optical pumping; praseodymium; radiative lifetimes; 10 W; 3 micron; Er3+ concentrations; Er3+, Pr3+-codoped ZBLAN fiber lasers; Er3+-doped crystal lasers; Er3+-singly-doped ZBLAN fiber lasers; Stokes efficiency; ZBLAN:Er3+,Pr3+; ZrF4-BaF2-LaF3-AlF3-NaF:Er,Pr; energy recycling; energy-transfer parameters; energy-transfer upconversion; erbium-doped 3-μm fiber lasers; laser transitions; lifetime quenching; output powers; population mechanisms; pump powers; slope efficiency; spectroscopic measurements; upper laser level; Energy measurement; Erbium; Erbium-doped fiber lasers; Laser excitation; Laser theory; Performance evaluation; Power lasers; Pump lasers; Recycling; Spectroscopy;
Journal_Title :
Quantum Electronics, IEEE Journal of
