Practical Techniques for the Measurement of Ultrashort Laser Pulses

超短激光脉冲测量实用技术

• 批准号: 9988706
• 负责人: Rick Trebino
• 金额: $ 27万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9988706&HistoricalAwards=false
• 关键词: Practical; Techniques; Measurement; Ultrashort; Laser

The measurement of ultrashort laser pulses remains an arduous task. Theautocorrelator, the device of choice for decades, is complex, comprising many components. The pulse must be split into two; the two pulses must then be spatially and temporally overlapped in a carefully alignedsecond-harmonic-generation (SHG) crystal; and the pulse relative delay must be scanned while maintaining alignment. Alignment involves four sensitive degrees of freedom and has great potential for error. Worse, bandwidth considerations require a very thin SHG crystal, which severely limits device sensitivity.Frequency-Resolved Optical Gating (FROG), which yields the full time-dependent pulse intensity and phase, requires adding a spectrometer to an autocorrelator apparatus, further complicating an already complicated apparatus. And FROG is the simplest proven intensity-and-phase measurement device. As a result, we have developed a remarkably simple,full-intensity-and-phase pulse-measurement device that 1) uses no spectrometer, 2) uses no beam-splitter or delay line, 3) avoids the thin crystal and instead uses a more convenient, thick SHG crystal, 4) is considerably more sensitive, 5) involves no sensitive alignment parameters,6) can measure a single pulse, and 7) comprises only a few simple optical components. It yields traces identical to those of SHG FROG, and hence yields the full time-dependent pulse intensity and phase. This device incorporates two key innovations: 1) a Fresnel biprism (a prism with a 170 apex angle), which replaces the beam splitter and delay line, and 2) a thicknonlinear crystal, whose output light is angularly resolved, yielding spectral resolution (as well as improved sensitivity and the usual time-gating), and which replaces the thin crystal and spectrometer.

超短激光脉冲的测量仍然是一项艰巨的任务。 theautocorlelator是数十年来首选的设备，它是复杂的，包括许多组件。 必须将脉冲分成两；然后，这两种脉冲必须在空间和时间上重叠在经过精心排列的谐波生成（SHG）晶体中；并且必须在保持对齐时扫描脉冲相对延迟。 对齐涉及四个灵敏的自由度，并且具有巨大的错误潜力。 更糟糕的是，带宽的考虑需要非常薄的SHG晶体，这严重限制了设备敏感性。频率分辨的光门控（Frog）产生了全日制依赖性的脉冲强度和相位，就需要在自动化器的设备中添加频谱仪，从而进一步复杂的设备。 青蛙是最简单的强度和相位测量装置。 结果，我们开发了一种非常简单的，全强的和相脉冲测定的设备，1）不使用光谱仪，2）不使用光束切割或延迟线，3）避免使用薄的晶体，而是使用更方便，更厚的SHG晶体，4）更敏感，5）仅涉及一个敏感的敏感性参数，而是一个单个脉冲，而是一个单个脉动，则可以使用7）。 它产生的痕迹与SHG青蛙的痕迹相同，因此产生了全日制依赖的脉冲强度和相位。 该设备结合了两个关键的创新：1）菲涅耳双i（一种具有170个顶点角的棱镜），它代替了光束拆分器和延迟线，以及2）厚的晶体晶体，其输出光是角度分辨的，可以使光谱分辨率（以及改善敏感性和敏感性和较薄的时间态），并替代了薄晶晶体和Speceportor。