A rapid swept-source mid-infrared laser
A rapid swept-source mid-infrared laser
复制标题
快速扫频中红外激光器
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
S. Matcher
中科院分区：
文献类型：
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作者：
D. Childs;A. Krysa;K. Kennedy;D. Revin;J. Cockburn;R. Hogg;S. Matcher
本文描述了一种扫频源型EC-QCL的设计与实现。由于基于振镜的移动质量小于衍射光栅的移动质量，因此构造了Littman外腔以实现快速扫描速率。我们演示了一个400 Hz的重复频率与调谐速度为45，000 cm-1/s。这两个品质因数都高于传统Littrow配置EC-QCL中实现的品质因数。调谐速度不受腔设计或增益芯片的限制，而是受所使用的移动反射镜的惯性的限制。我们继续评估我们的扫频源的扫频速率的基本限制。一个关键因素是达到饱和所需的空腔往返次数。该光子建立时间取决于腔长、往返增益、腔线宽和腔光谱窗口内的ASE功率[4]。据我们所知，这是QCL增益芯片用于快速扫频源应用的首次评估。我们证明，> 100 kHz的重复率应该是可能的扫频源EC-QCL。
In this paper we describe the design and realization of a swept-source EC-QCL. Since the moving mass of a galvanometer based mirror is less than that of a diffraction grating, a Littman external cavity was constructed to enable rapid sweep rates. We demonstrate a 400Hz repetition rate with a tuning speed of 45,000cm-1/s. Both figures of merit are higher than those achieved in conventional Littrow configuration EC-QCLs. The tuning speed is not limited by the cavity design or gain chip but by the inertia of the moving mirror used. We go on to assess the fundamental limit to the sweep rate of our swept-source. A key factor is the number of round trips of the cavity that are required to reach saturation. This photon build up time is dependent on the cavity length, the round trip gain, the cavity linewidth, and the ASE power within the spectral window of the cavity [4]. To the best of our knowledge, this is the first assessment of QCL gain chips for rapid swept-source applications. We demonstrate that >100kHz repetition rate should be possible from sweptsource EC-QCLs.