Fine tuning of terahertz generation in fan-out type periodically poled lithium niobate using femtosecond laser pulses

The terahertz pulse generated from a fan-out type periodically poled lithium niobate was investigated. Due to the position-different period of the fan-out type structure, the center frequency of the terahertz radiation changes when an incident position of a pump laser varies. The center frequency of terahertz pulse can also be tuned finely by changing an incident angle of the pump laser.