Glass-ceramics withγ-Ga₂O₃:Co²⁺nanocrystals: saturable absorber for 1.5–1.7 μm Er lasers

Abstract

Transparent glass-ceramics containing γ-Ga 2 O 3 :Co 2+ nanosized (7-12 nm) crystals are synthesized in a lithium gallium silicate system. Their spectroscopic and nonlinear properties are studied. The absorption band related to the 4 A 2g ( 4 F) → 4 T 1g ( 4 F) transition of Co 2+ ions in tetrahedral sites for these glass-ceramics is red-shifted up to ~1.8 μm. The absorption saturation fluence is determined to be ~0.8 J cm −2 . The developed glass-ceramics are used for passive Q-switching of diode-pumped Er,Yb:glass laser delivering 1.75 mJ 25 ns-long pulses at 1540 nm.

Development of Saturable Absorbers for Laser Passive Q‐Switching near 1.5 μm Based on Transparent Ceramic Co2+:MgAl2O4

“…This tendency agrees with previous observations. 13 In Fig. 9 we show the dependencies of the absorption coefficient a on the incident pump fluence F for both the Co 2+ :MgAl 2 O 4 transparent ceramic and the Co 2+ :ZnAl 2 O 4 nanocrystals containing glass-ceramic samples.…”

“…4 I 15/2 emission of Er 3+ , passive Co 2+ :Mg(Zn)Al 2 O 4 Q-switches represent an efficient solution. [7][8][9][10][11][12][13][14][15][16][17] Until recently, only doped single-crystals or glass-ceramic (low scale)-based saturable absorbers were practically employed. While such switches are useful, they do have certain drawbacks.…”

1 mJ single-rod fiber Er:glass laser for rangefinding

“…Previously we have developed different types of Co-doped spinel based glass-ceramics for passive Q-switches 8,9 . In this work, we used two novel glass-ceramics containing Co 2+ :MgAl2O4 nanocrystals and γ-Ga2O3:Co 2+ nanocrystals 10 .…”

Compact 0.7 mJ/11 ns eye-safe erbium laser

“…Recently, transparent glass-ceramics (GCs) containing various Co 2+ -doped nanocrystals, e.g. MgAl 2 O 4 [14], ZnAl 2 O 4 [15], γ-Ga 2 O 3 [16], and ZnO [17], have been studied for the replacement of single crystalline SAs. The GCs are synthesized by a cost-effective melt-quenching method with subsequent heat-treatments and possess good optical homogeneity [14,15].…”

“…The GCs are synthesized by a cost-effective melt-quenching method with subsequent heat-treatments and possess good optical homogeneity [14,15]. The nonlinear properties and laser-induced damage threshold (LIDT) for GCs are comparable or even advantageous with respect to the Co 2+ :MgAl 2 O 4 single crystals [14][15][16].…”