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

Abstract

We describe the development of a reasonable cost P parent excited state. Obtained specimens had a transmission of~80% (t = 2 mm, k = 600 nm) and included some opaque, white spots. Further improvement of host optical transmission and resistance to laser damage are necessary.

Transparent Ceramics at 50: Progress Made and Further Prospects

“…The main advantage of ceramics over single‐crystals is lower cost; compared to glass‐ceramics, they exhibit the ability to withstand higher energy pulses without damage and have lower sensitivity to thermal shock. Figure shows the saturation curve of such a component, together with the Co 2+ ( T d ) electronic levels in which the desired and parasitic transitions are marked …”

“…α [cm −1 ] as a function of energy fluence at λ = 1540 nm (from Ref. ; reproduced with permission). [1] 0.07 at.% Co:spinel ceramic.…”

Fabrication and properties of Co:MgAl2O4 transparent ceramics for a saturable absorber from coprecipitated nanopowder

“…After calcination, the precursor was completely transformed into pure MgAl 2 O 4 phase . The similar radius (the radii of Mg 2+ and Co 2+ are 0.069 and 0.072 nm) and the same electrical charge of Mg 2+ and Co 2+ make it easy for Co 2+ to substitute for the Mg 2+ in T d site . The calculated lattice parameter of 0.05 at.% Co:MgAl 2 O 4 powder is 0.8081 nm.…”

“…In order to obtain a uniform distribution of doping ions, the concentration of Co 2+ was usually selected as 0.04‐0.07 at.% range, a 0.05 at.% was chosen in this work. Basing on the reverse strike coprecipitation method, 0.05 at.% Co:MgAl 2 O 4 nanopowder was synthesized by the wet‐chemical method.…”

“…On the basis of the preparation of high‐quality MgAl 2 O 4 transparent ceramics, in 2016, A. Goldstein et al. acquired Co:MgAl 2 O 4 transparent ceramics and achieved application in laser . These ceramic specimens had a transmission of ~80% ( t = 2 mm, λ = 600 nm) but included some opaque and white spots.…”