Lacot Eric, Glastre Wilfried, Jacquin Olivier, Hugon Olivier, Guillet de Chatellus Hugues
Centre National de la Recherche Scientifique/Université de Grenoble 1, Laboratoire Interdisciplinaire de Physique, UMR 5588, Grenoble F-38402, France. eric.lacot@ujf‑grenoble.fr
J Opt Soc Am A Opt Image Sci Vis. 2013 Jan 1;30(1):60-70. doi: 10.1364/JOSAA.30.000060.
In autodyne interferometry, the beating between the reference beam and the signal beam takes place inside the laser cavity and therefore the laser fulfills simultaneously the roles of the emitter and the detector of photons. In these conditions, the laser relaxation oscillations play a leading role, both in the laser quantum noise that determines the signal-to-noise ratio (SNR) and also in the laser dynamics that determine the response time of the interferometer. In the present study, we have theoretically analyzed the SNR and the response time of a laser optical feedback imaging (LOFI) setup based on an autodyne interferometer. More precisely, we have compared the image quality of two lasers having the same output power and the same relaxation frequency, but having two different values of the LOFI gain induced by two different values of the laser response time. From this study, we have finally determined the best laser dynamical parameters and the best experimental conditions for high-speed imaging at the shot-noise limit. Finally, we conclude that a laser diode with a very short response time (in the nanosecond range) seems to be an interesting candidate compared to solid-state microchip laser with a response time of several tens of microseconds. Analytical predictions are confirmed by numerical simulations.
在自差干涉测量中,参考光束与信号光束之间的拍频发生在激光腔内,因此激光同时充当光子的发射源和探测器。在这些条件下,激光弛豫振荡起着主导作用,这在决定信噪比(SNR)的激光量子噪声以及决定干涉仪响应时间的激光动力学中均是如此。在本研究中,我们从理论上分析了基于自差干涉仪的激光光学反馈成像(LOFI)装置的信噪比和响应时间。更确切地说,我们比较了两台输出功率相同、弛豫频率相同,但由两种不同的激光响应时间值所诱导的LOFI增益不同的激光器的图像质量。通过这项研究,我们最终确定了在散粒噪声极限下进行高速成像的最佳激光动力学参数和最佳实验条件。最后,我们得出结论,与响应时间为几十微秒的固态微芯片激光器相比,响应时间非常短(在纳秒范围内)的激光二极管似乎是一个有趣的候选者。分析预测通过数值模拟得到了证实。