| Nonlinear optical coefficients: |
 |
| d36 (1.064 mm) = 1.8 d36
( AgGaS2 ) ± 15% = (35.2 ± 5.3 ) pm/V |
|
| d31 (1.064 mm) = 0.6 d36
( AgGaS2 ) ± 15% = (11.7 ± 1.8 ) pm/V |
|
| d36 / d31 = +3 |
|
| dooe = d36 sin q sin 2j +
d31 sin q cos 2j
jopt = 36o; |
|
| deoe = doee = d36 sin 2q cos 2j -
d31 sin 2q sin 2j
jopt = 81o. |
|
Dispersion of refractive indices ( Sellmeier equations, l in mm ) |
|
| n2o = 6.2081522 - 63.706298 / ( 225.0 - l2 ) - 0.23698804 / ( 0.09568646 - l2 ); |
|
| n2e = 6.0090267 - 63.280659 / ( 225.0 - l2 ) - 0.21489656 / ( 0.09214633 - l2 ). |
|
Conversion efficiency for CO2 laser 10% (t = 30 ns,
power density 60 MW/cm 2, L = 4 mm)
|
Application |
|
We have priority in growth of HgGa2S4 nonlinear crystals.
High values of laser damage threshold and conversion efficiency allow to use those crystals for frequency doubling and
OPO/OPA in the wavelength range from 1.0 to 10 mm. It was established that SHG efficiency
of CO2 laser radiation for 4 mm length HgGa2S4 element is about 10 % ( pulse duration 30 ns,
radiation power density 60 MW/cm2). The high conversion efficiency and wide range of radiation wavelength
tuning allows to expect that this material may compete with AgGaS2, AgGaSe2, ZnGeP2 and
GaSe crystals in spite of the considerable difficulty of big size crystals growth process. |
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