PPKTP Crystal

The periodic polarized KTP (PPKTP) is a novel nonlinear optical material that can be customized to achieve all of the nonlinear applications required in the entire KTP crystal transmission band, without the phase matching limitations of conventional KTP. Moreover, the effective nonlinear coefficient of PPKTP is about 3 times higher than that of conventional KTP. In the nonlinear application of conventional KTP, the crystal must have a single domain structure, but PPKTP crystal has an artificially induced periodic domain structure. The size of the polarization interval varies depending on the application, ranging from a few microns to tens of microns. The polarization direction is usually along the direction with the largest nonlinear coefficient in the crystal, which is also different from conventional KTP, where the axial direction is determined by the constraints to achieve phase matching.

PPKTP is manufactured by depositing a structured electrode plate on the surface of the KTP single-domain substrate using microlithography. Then an electric field is applied to the crystal under precisely controlled conditions, resulting in the desired changes in the domain structure. After the polarized crystals are tested and qualified, they are cut to the desired size and finally polished and coated.

WISOPTIC provides standard PPKTP devices, including 1064nm and 946nm frequency multiplier (SHG) devices, OPO devices, etc., as well as other customized devices for special purpose. Temperature control technique is needed to use the periodic polarized crystal, which can be flexibly controlled by computer interface.

Second Harmonic Generation in Periodically Poled and Bulk KTP

Test Conditions:  Crystal length = 10 mm; τ = 10 ns; Pulse frequency = 2 kHz