Simultaneous wavenumber measurement and coherence detection using temporal phase unwrapping.
Simultaneous wavenumber measurement and coherence detection using temporal phase unwrapping.
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DOI：
10.1364/ao.51.000558
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发表时间：
2012-02
期刊：
影响因子：
1.9
通讯作者：
Abundio Davila;J. M. Huntley;C. Pallikarakis;Pablo D. Ruiz;J. Coupland
中科院分区：
文献类型：
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作者：
Abundio Davila;J. M. Huntley;C. Pallikarakis;Pablo D. Ruiz;J. Coupland
波长扫描干涉术和扫频光源光学相干层析成像技术需要精确测量激光波数随时间的变化。我们在这里描述了一种方法的基础上记录干涉图的多个楔形，同时提供高波数分辨率和免疫力的模糊性所造成的大波数跳跃。计算波数偏移所需的所有数据都在单个图像中提供，从而允许动态波数监测。此外，自动检测激光的相干性损失。本文给出了详细的分析算法，是基于相位检测的二维傅里叶变换方法，然后通过时间相位展开和校正光色散的楔形。还描述了一种简单但稳健的方法来确定楔厚度，该方法允许使用低成本的光学元件。该方法示出了从钛：蓝宝石可调谐激光器的实验数据，包括独立的波数测量与商业波长计。两者之间的测量波数偏移的均方根（rms）差为~4 m m ²，相当于均方根波长偏移误差为~0.4 pm。
Wavelength scanning interferometry and swept-source optical coherence tomography require accurate measurement of time-varying laser wavenumber changes. We describe here a method based on recording interferograms of multiple wedges to provide simultaneously high wavenumber resolution and immunity to the ambiguities caused by large wavenumber jumps. All the data required to compute a wavenumber shift are provided in a single image, thereby allowing dynamic wavenumber monitoring. In addition, loss of coherence of the laser light is detected automatically. The paper gives details of the analysis algorithms that are based on phase detection by a two-dimensional Fourier transform method followed by temporal phase unwrapping and correction for optical dispersion in the wedges. A simple but robust method to determine the wedge thicknesses, which allows the use of low-cost optical components, is also described. The method is illustrated with experimental data from a Ti:sapphire tunable laser, including independent wavenumber measurements with a commercial wavemeter. A root mean square (rms) difference in measured wavenumber shift between the two of ~4 m⁻¹ has been achieved, equivalent to an rms wavelength shift error of ~0.4 pm.