近红外瞬态脉冲波前高精度干涉检测技术

Measurement of Transient Near-Infrared Laser Pulse Wavefront with High Precision by Radial Shearing Interferometer

惯性约束聚变（ICF）系统中高能瞬态脉冲激光由于脉冲时间短、能量高、波前畸变大，通常的检测方法难于检测脉冲激光波前。提出了一种基于空间相位调制技术可用于近红外瞬态波前高精度检测的环形径向剪切干涉仪。该系统可以以Ф30～150mm的圆瞳和方瞳口径、对波长为1064nm的近红外纳秒级脉宽的脉冲激光波前实现共路、无参考面的瞬态、高精度的检测。系统的波前重构理论经过计算机仿真验证，精度达1／1000λ以上；检测结果与ZYGO数字波面干涉仪进行了比对，峰谷值、均方根值均优于1／15λ，并具有很好的可重复性。该系统目前已用于惯性约束聚变系统的脉冲检测，并且该技术适用于各种可见光和红外波段激光。

Its hard to measure the transient pulsed laser wavefront in inertial confinement fusion （ICF） system by the conventional methods for its short pulse width, large energy, high power and large distortion. An circular radial shearing interferometer based on spatial phase modulation is proposed to measure the transient near infrared laser pulse wavefront with high precision. Transient, highly precise measurement for near-infrared laser pulse wavefront, with pulse width of nanometer scale and central wavelength of 1064 nm, can be carried out with common-path and no reference plane with round and rectangular aperture ranging from Ф30-150 mm. Theory of wavefront reconstruction has been validated by the computer simulation, and an error less than 1/1000λ is obtained. Compared with the results of ZYGO interferometer, an error less than 1/15λ for both peak-valley and root mean square value, is gained with good repeatability. The system has already been used in the ICF system to test the pulsed laser wavefront, and can also be applied to other visible and infrared lasers.