Nanosecond Compact Eye-Safe Erbium Lasers with 190 kW Peak Power

Spinel (MgAl 2 O 4 ) single crystals doped with cobalt ions (Co 2+ ) are known as efficient saturable absorbers (SAs) of eye-safe erbium (Er) laser emitting at 1.5–1.7 μm. Their saturable absorption originates from the 4 A 2 ( 4 F) → 4 T 1 ( 4 F) transition of Co 2+ ions located in tetrahedral (T d ) sites. Recently, Co 2+ -doped spinel transparent polycrystalline ceramics and transparent nanophase glass-ceramics (GCs) were proposed as competitive materials for the single-crystal technology [1] , [2] . Among them, transparent GCs feature high laser induced damage thresholds (~20 J/cm 2 ) and the possibility to modify the composition of spinel nanophase [1] . We report on a compact passively-cooled eye-safe Er laser passively Q-switched (PQS) by GC-based SAs suitable for compact range-finders.