Schmitt J M
Department of Electrical and Electronic Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Phys Med Biol. 1997 Jul;42(7):1427-39. doi: 10.1088/0031-9155/42/7/015.
This paper introduces a spatial-diversity method for speckle suppression in optical coherence microscopy. The method is based on combining interference signals from an array of detectors placed in the back focal plane of the objective lens, such that elements receive light backscattered from the sample volume at different angles. Incoherently adding ('compounding') the signals increases the signal-to-noise ratio of the processed image compared to that attainable with a single detector. The speckle-reduction method was demonstrated with a benchtop microscope equipped with a quadrant photodiode. To evaluate its potential application in dermatology, images of living skin acquired with and without compounding were compared. The quality of the compounded images was found to be substantially better. A signal-to-noise gain close to a factor of two (the theoretical maximum attainable using four detectors) was achieved without a significant loss in resolution. The method can be applied to arrays with a larger number of elements, potentially enabling more advanced forms of spatial-diversity and adaptive-optics methods.
本文介绍了一种用于光学相干显微镜中散斑抑制的空间分集方法。该方法基于组合来自放置在物镜后焦平面的探测器阵列的干涉信号，使得各元件接收从样品体积以不同角度反向散射的光。与单个探测器相比，对信号进行非相干相加（“复合”）可提高处理后图像的信噪比。使用配备象限光电二极管的台式显微镜演示了散斑减少方法。为了评估其在皮肤病学中的潜在应用，比较了有复合和无复合情况下获取的活体皮肤图像。发现复合图像的质量明显更好。在分辨率没有显著损失的情况下，实现了接近两倍的信噪比增益（使用四个探测器理论上可达到的最大值）。该方法可应用于具有更多元件的阵列，有可能实现更先进形式的空间分集和自适应光学方法。
