Synthesized femtosecond laser pulse source for two-wavelength contouring with simultaneously recorded digital holograms.
Synthesized femtosecond laser pulse source for two-wavelength contouring with simultaneously recorded digital holograms.
复制标题
DOI：
10.1364/oe.17.002686
复制
发表时间：
2009-02
期刊：
影响因子：
3.8
通讯作者：
T. Hansel;G. Steinmeyer;R. Grunwald;C. Falldorf;J. Bonitz;C. Kaufmann;V. Kebbel;U. Griebner
中科院分区：
文献类型：
--
作者：
T. Hansel;G. Steinmeyer;R. Grunwald;C. Falldorf;J. Bonitz;C. Kaufmann;V. Kebbel;U. Griebner
介绍了一种双波长飞秒激光脉冲源及其在数字全息单次轮廓测量中的应用。合成的激光光源结合了亚皮秒时间尺度和宽重建范围。通过对以800 nm为中心的50 nm宽的种子光谱进行整形，证明了两个分离的高对比度脉冲的中心波长距离仅为15 nm。由于产生的合成波长，没有相位模糊的扫描深度范围被扩展到100微米范围。在Twyman-Green干涉仪中使用两个cmos摄像机，并通过偏振编码序列对全息图进行扩展，实现了单次拍摄的双波长成像。给出了该方法的原理，并给出了工作在0.5 kHz的单轴扫描镜的实验结果。在合成波长范围内，明确地提取了目标的相位差信息，并计算了三维形状。据我们所知，这是第一次报道亚ps时间尺度上的单激发双波长等高线。
A dual-wavelength femtosecond laser pulse source and its application for digital holographic single-shot contouring are presented. The synthesized laser source combines sub-picosecond time scales with a wide reconstruction range. A center wavelength distance of the two separated pulses of only 15 nm with a high contrast was demonstrated by spectral shaping of the 50 nm broad seed spectrum centered at 800 nm. Owing to the resulting synthetic wavelength, the scan depth range without phase ambiguity is extended to the 100-microm-range. Single-shot dual-wavelength imaging is achieved by using two CMOS cameras in a Twyman-Green interferometer, which is extended by a polarization encoding sequence to separate the holograms. The principle of the method is revealed, and experimental results concerning a single axis scanner mirror operating at a resonance frequency of 0.5 kHz are presented. Within the synthetic wavelength, the phase difference information of the object was unambiguously retrieved and the 3D-shape calculated. To the best of our knowledge, this is the first time that single-shot two-wavelength contouring on a sub-ps time scale is reported.