Trapped charge density analysis of KTN crystal by beam path measurement.

Because the function of a single crystal of potassium tantalate niobate (KTa(1-x)Nb(x)O(3), KTN) is largely decided by the trapped charge density inside it, it is essential to determine its value. We quantitatively estimate the charge density using two optical analysis methods, namely by investigating KTN's deflection angle when it is used as a deflector and by investigating KTN's focal length when it is used as a graded-index (GRIN) lens. A strobe technique is introduced with which to perform the measurement.

Fast response varifocal lenses using KTa(1-x)Nb(x)O3 crystals and a simulation method with electrostrictive calculations.

We fabricated cylindrical varifocal lenses with fast responses by using the strong Kerr effect of KTa(1-x)Nb(x)O(3) (KTN) single crystals. We observed focus shifts of up to 87 mm with the assistance of a 250 mm focal length lens, which corresponds to a focus shift from infinity to 720 mm by the KTN lens itself. The response time was as fast as 1 μs.