Tuning, temporal, and spectral characteristics of the green (lambda similar to 549 nm), holmium-doped fluorozirconate glass fiber laser

The output power, tuning and temporal behavior of the green (539-550 nm), Ho-doped fluorozirconate glass (ZBLAN) fiber laser pumped in the red (lambda similar to 643 nm) has been examined in detail. Fibers ranging in length from similar to 20-86 cm have been studied, and more than 38 mW of output power has been obtained from a 21 cm long fiber for 30% output coupling and 280 mW of absorbed pump power, By inserting two prisms into the optical cavity, the oscillator has been tuned over similar to 11 nm, and the emission spectrum of the free-running laser has been recorded as a function of pump power at both room temperature and 77 K, The self-pulsing (spiking) behavior of the laser and the influence of depletion of the Ho3+ ground state (I-5(8)) population on the emission spectrum and efficiency of this system are discussed.