We demonstrate a compact core-pumped 2 μm Tm3+, Ho 3+-doped all-fiber laser passively Q-switched with an antimony-based saturable absorber. The 20 ns pulses are the shortest Q-switched pulses from a fiber laser operating beyond 1850 nm and were produced at a repetition rate of 57 kHz and pulse energy of 15 μJ using a short-length (4 ns) cavity. The large absorber modulation depth of ∼70% together with transient gain compression is shown to provide an efficient mechanism for Q-switched pulse shortening.
|Number of pages||6|
|Publication status||Published - 22 Dec 2008|