理学院数理讲坛（2014年第十八讲）
报 告 人：徐长青教授(加拿大McMaster大学工程物理系)
报告题目：PPLN based green lasers for laser display applications
报告时间：2014年5月19日上午10:00
报告地点：理北311会议室
研究方向：
Photonic devices, Nonlinear optical materials and devices, Optical sensors and lasers, Laser applications.
PPLN简介：
PPLN stands for periodically poled lithium niobate. In PPLN, sign of nonlinear coefficient changes periodically due to the periodical domain inversion along the beam propagation direction of a z-cut lithium niobate substrate. As a result, the quasi-phase matching (QPM) condition required for efficient wavelength conversion can be satisfied by choosing a proper period of the PPLN. Domain inversion is realized by moving Li ion in lithium niobate crystal from one to another stable position through applying very high electric field across the substrate.
PPLN chips provide a highly efficient method to convert wavelength of commercially available semiconductor laser diodes to wavelengths that are not accessible to the laser diodes based on nonlinear effects within PPLN. The converted wavelength can range from 350 nm to nearly 5000 nm by choosing proper period of PPLN and the pumping wavelength. This technique is especially useful in generating red, green, blue (i.e. RGB) light required in laser display and mid-infrared light required in optical sensing.
欢迎各位老师和学生参加！