Direct measurements of the terminal laser level lifetime in neodymium-doped crystals and glasses

Dynamics of Continuously Pumped Solid-State Regenerative Amplifiers

“…Comprehensive evaluation of actual terminal-level lifetime provided by (Bibeau, et al, 1995) for different neodymium doped laser media gives actual values well exceeding 100 ps. So we can conclude that amplification of pulses shorter than 100ps virtually for all neodymium based systems is more appropriate to analyze within the short pulse approximation that is assuming negligible terminal-level depopulation during singe pulse amplification.…”

“…The latter is the case since we assume the terminal-level lifetime to be much shorter than the round trip time, T 0 . Typical T 0 value is in the range between ten and a few tens of nanoseconds, so this is good approximation for most of neodymium media [actually except some fluoride crystals and glasses in which the neodymium terminal lifetime is of 10 ns order (Bibeau, et al, 1995)]. By this means and by using sequential procedure the basic relations ) ( ai a af g g g = and corresponding output energies were determined.…”

<title>Gain saturation studies in LG-750 and LG-770 amplifier glass</title>

“…Since the terminal level lifetime is on the order of 225 ps in LG-750 [48], the 20-ns Milam Yarema data should be experimentally indistinguishable from 17-ns OSL data. The best fit to the Milam Yarema data using the single-ion model for a 20 ns pulse length is obtained using an average saturation fluence value of 4.52 J/cm 2 , assuming a cross-section of 3.6 x 10 -20 cm 2 .…”

“…[48] However, the terminal level lifetime can be affected by the composition of the glass. The terminal level lifetimes of four Nd:doped phosphate glasses and one Nd:doped crystal are given in Table 2, along with the partial compositions of the glasses.…”

“…The terminal level lifetimes of four Nd:doped phosphate glasses and one Nd:doped crystal are given in Table 2, along with the partial compositions of the glasses. [48] The terminal level lifetime tends to decrease as lighter compounds replace heavier ones in the glass composition. While this does not appear to apply in the case of LG-770, it is possible that the composition of the glass, which is currently proprietary, is sufficiently different from the glasses measured to date to cause a longer lower level lifetime.…”