SBIR Phase I: Simple Device for Measuring Nanosecond Laser Pulses

这个小型企业创新研究（SBIR）第一阶段项目提出开发一种简单，单发，廉价，完整的激光脉冲测量设备，用于~ 100 ps至~ 10 ns脉冲。虽然长脉冲（10 ns）很容易测量，并且最近开发的技术完全测量超短脉冲（10 ps），但中等长度~ 1 ns的脉冲仅保持部分和大致可测量，因此，这种脉冲通常保持复杂和不稳定。这是不幸的，因为大多数商业脉冲激光器发射的脉冲在这个中间范围内。所提出的测量设备扩展了频率分辨光学选通（FROG），这是一种非常成功的技术，用于测量超短脉冲的完整强度和相位与时间的关系，该技术通过测量脉冲的频谱图来操作。将FROG扩展到更长脉冲的主要挑战是在单次发射上产生许多ns的延迟范围-目前这是一个未解决的问题。所提出的创新通过将输入脉冲倾斜显著的~89.9°而不使其在时间上失真来解决它。因此，一个约1厘米宽的光束的一边领先另一边超过一米。所提出的ns FROG可以测量非常复杂的脉冲，并且成本约为目前用于仅部分测量此类脉冲的高带宽示波器的十分之一。该项目更广泛的影响/商业潜力将扩展到大多数脉冲激光器，从Q开关和增益开关固态激光器到光纤激光器，它们发出~ns脉冲并具有许多应用。所有这些应用都将受益于该设备。首先，~ns-laser用户现在将有一个设备来测试他们的激光？的性能，它将是简单的，易于使用，单次拍摄，相对便宜。它将是至关重要的尝试相干联合收割机脉冲从多个光纤激光器，通常被认为是下一个重要的步骤，在高功率光纤激光器的发展。注入种子Q开关和增益开关激光器，奋进发出非常干净的~ns脉冲，也需要这样的方法进行性能确认。最后，一般激光工程师将能够更好地提高~ ns激光脉冲的质量，大大有利于所有的~ ns脉冲激光实验和应用。如果在超短脉冲测量技术被引入之后，超快激光器的惊人进展是任何迹象的话，那么这种用于测量ns脉冲的廉价而简单的设备应该在产生更稳定的~ns脉冲方面产生巨大的差异，从而在使用这种激光器的许多领域中产生巨大的差异，从焊接到外科手术到材料加工到距离测量到遥感。

This Small Business Innovation Research (SBIR) Phase I project proposes to develop a simple, single-shot, inexpensive, and complete laser-pulse measurement device for ~100ps to ~10ns pulses. While long (10ns) pulses are easily measured, and recently developed techniques completely measure ultra-short pulses (10ps), intermediate-length ~1ns, pulses remain only partially and roughly measurable, and, consequently, such pulses generally remain complex and unstable. This is unfortunate because most commercial pulsed lasers emit pulses in this intermediate range. The proposed measurement device extends Frequency-Resolved Optical Gating (FROG), a very successful technique for measuring the complete intensity and phase versus time of ultra-short pulses, which operates by measuring the pulse's spectrogram. The main challenge in extending FROG to much longer pulses is the generation of a many-ns delay range on a single shot - currently an unsolved problem in general. The proposed innovation solves it by tilting the input pulse by a remarkable ~89.9° without distorting it in time. As a result, one side of a ~1cm-wide beam precedes the other by over a meter. The proposed ns FROG can measure even very complex pulses and will cost about one tenth as much as the high bandwidth oscilloscopes currently used to only partially measure such pulses. The broader impact/commercial potential of this project will extend to most pulsed lasers, from Q-switched and gain-switched solid-state lasers to fiber lasers, which emit ~ns pulses and have many applications. All such applications will benefit from this device. First, ~ns-laser users will now have a device to test their laser?s performance, and it will be simple, easy to use, single-shot, and relatively inexpensive. It will be essential in attempts to coherently combine pulses from multiple fiber lasers, generally regarded as the next important step in high-power fiber-laser development. Injection-seeded Qswitched and gain-switched lasers, which endeavor to emit very clean ~ns pulses, are also in need of such a method for performance confirmation. Finally, laser engineers in general will be better able to improve the quality of ~ns-laser pulses, greatly benefitting all ~ns-pulsed-laser experiments and applications. If the spectacular progress in ultrafast lasers that occurred after complete ultra-short-pulse-measurement technology was introduced is any indication, such an inexpensive and simple device for measuring ns pulses should make a huge difference in the generation of ever more stable ~ns pulses and consequently in the many fields that use such lasers, from welding to surgery to material processing to distance measurements to remote sensing.