Abstract

The efficiency at which a four-level laser operates, depends in part on the relative value of the terminal-level lifetime with respect to the laser pulse width. This is an especially important consideration for high peak-power systems where pulse lengths on the order of picoseconds to nanoseconds are required. For neodymium-doped laser materials, the terminal-level lifetime corresponds to the nonradiative transition from the ⁴I_11/2 level down to the ⁴I_9/2 ground state. This transition is accompanied by the transfer of energy from the excited neodymium ions to the surrounding medium. Therefore, the value of the lifetime will vary from host to host depending on the details of surrounding network or lattice and its phonon spectrum.

© 1994 Optical Society of America