APPARATUS FOR THERMALLY INDUCED DEPOLARISATION COMPENSATION IN LASER ABSORBING OPTICAL ELEMENT Russian patent published in 2012 - IPC H01S3/10 G02F1/01 

FIELD: physics.

SUBSTANCE: apparatus includes, arranged in series on an optical axis, a mutual polarisation rotator which rotates the polarisation plane of transmitted radiation by an angle φ and a compensating optical element placed behind an absorbing optical element. The compensating element is an optical element having, for the same parameters of laser radiation, thermally induced depolarisation γ₁ approximately equal to γ₀: γ₁ (P₁, Q₁, k₁, ξ₁, α₁, L₁, W) ≈ γ₀ (P₀, Q₀, k₀, ξ₀, α₀, L₀, W), where P and Q are thermo-optical parameters of the element, k₀ is the thermal conductivity coefficient of the element, ξ₀ is the optical anisotropy parameter of the material of the element, α₀ is the absorption coefficient of the material of the element, L₀ is the length of the element, W is the laser radiation power. At least one of said parameters, from which γ₁ depends, is not equal to the corresponding parameter γ₀, and angle φ of the mutual polarisation rotator and the distinctive parameters of the compensating element are determined by the selection of the material of the compensating element and the condition for minimum total thermally induced depolarisation in the absorbing element-mutual polarisation rotator-compensating element system.

EFFECT: possibility of compensating for thermally induced depolarisation in any predetermined laser absorbing optical element.

4 cl, 3 dwg