Measurement of the spatial coherence of superluminescent diodes
Measurement of the spatial coherence of superluminescent diodes
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DOI：
10.1080/09500349908231370
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发表时间：
1999-10-15
影响因子：
1.3
通讯作者：
Fercher, AF
中科院分区：
文献类型：
--
作者：
Hitzenberger, CK;Danner, M;Fercher, AF
近年来，超发光二极管（SLDs）作为部分相干干涉测量和光学相干层析成像的光源变得越来越重要。sld的要求是高空间相干性，低时间相干性，并且在某些应用中需要高功率。由于这些特性之间可能存在权衡，我们建立了一个测量SLDs空间相干性的仪器。该仪器由一个混合体光纤马赫-曾德尔干涉仪组成。该仪器的特殊优点是能够测量光束内任意点之间的空间相干性，并能直接观测光束内的测量点，便于对准。我们使用该仪器评估了几种市售SLDs的空间相干性。正如预期的那样，单模光纤尾纤SLD具有最佳的空间相干性。如果考虑自由空间发射的SLD，芯片结构更复杂的SLD空间相干性稍差，但其时间相干性明显优于仅涂有增透涂层的SLD。
In recent years, superluminescent diodes (SLDs) have gained increasing importance as light sources for partial coherence interferometry and optical coherence tomography. The requirements of SLDs are high spatial coherence, low temporal coherence, and, for some applications, high power. Since there might be a trade-off between these properties we built an instrument for measuring the spatial coherence of SLDs. This instrument consists of a hybrid bulk optic-fibre optic Mach-Zehnder interferometer. The special advantages of the instrument are the ability to measure the spatial coherence between arbitrary points within the light beam and to observe directly the measurement points within the beam which facilitates the alignment. We used this instrument to evaluate the spatial coherence of several commercially available SLDs. As expected, a single mode fibre pigtailed SLD shows the best spatial coherence. If free-space emitting SLDs are considered, those with a more complicated chip structure have a somewhat poorer spatial coherence, however, their temporal coherence is considerably better than that of a SLD which is only antireflection coated.