Investigation on probing quadratic electro-optic coefficient of tantalum potassium niobate crystal based on Fourier transform

• A method for probing quadratic electro-optic (QEO) coefficient of tantalum potassium niobate crystal based on Fourier transform was proposed.
• The phase differences of deformed interference fringes introduced by quadratic electro-optic effect is extracted by Fourier transform, the refractive index change is further calculated according to structure of the actual light beam path.
• All the independent component of QEO coefficient tensor of KTN crystal was acquired with the help of the computer digital image processing technology.

A method for probing quadratic electro-optic(QEO) coefficient of tantalum potassium niobate crystal based on Fourier transform was proposed. We acquired all the independent component of QEO coefficient tensor of crystal, they are h11=1.56×10-14m2/V2, h12=1.24×10-14m2/V2 and h44=0.160×10-14m2/V2 respectively. With the help of the computer digital image processing technology, this method should have further application prospect in the areas of optical properties parameters measuring to the optical functional materials.