Location: HOMEPRODUCTSCRYSTALSPassive Q-switch

Co2+:MgAl2O4 crystals

Co2+:MgAl2O4 is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6 μm, in particular, for eye-safe 1.54 μm Er:glass laser, but also works at 1.44 μm and 1.34 μm wavelengths. Spinel is a hard, stable crystal that polishes well. Cobalt substitutes readily for magnesium in the Spinel host without the need for additional charge compensation ions. High absorption cross section (3.5×10-19 cm2) permits Q-switching of Er:glass laser without intracavity focusing both with flash-lamp and diode-laser pumping. Negligible excited-state absorption results in high contrast of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.



High optical quanlity;

With uniform Co distribution;

High absorption cross section;

Negligible excited-state absorption;


HG Offers Cospinel Specifications


The rod axis is along [111] within5°

Co concentration    

0.05 atm% ~ 0.3 atm%

OD(Optical density)

0.1 ~ 0.9   

absorption coefficient

1.0cm-1~7 cm-1

Initial transmission  

30% ~ 99%

Cross Section

3.5 x 10-19cm2


λ /8 @ 633 nm






10 arc sec


5 arc minutes

Surface finishing   

10/5 scratch/dig to MIL-O-13830A    

Wavefront distortion    

λ/8 @ 633 nm


AR/HR/PR coating upon customer’s request

Note:  When ordering Cospinel crystal, please specify the aperture, initial transmission(To) and coatings.