Q-switched induced gain switching of a twotransition cascade laser

A gain-switched laser transition, of a two-laser-transition cascade laser, that is driven by the adjacent laser transition which is Q-switched is demonstrated using a Ho3+-doped fluoride fiber laser. Q-switching the ⁵I₆ ? ⁵I₇ transition at 3.002 μm produces stable gain-switched pulses from the ⁵I₇ → ⁵I₈ transition at 2.074 μm; however, Q-switching the ⁵I₇ → ⁵I₈ transition produced multiple gain switched pulses from the ⁵I₆ → ⁵I₇ transition. The gain-switched pulses were measured to be of a similar duration to the Qswitched pulses suggesting that much shorter pulses of closer duration could be generated at pump power higher levels.