Phase imaging without a phase wrapping ambiguity is required for wide-axial-range 3D imaging in the fields of surface topography measurement and biomedical imaging. Although multicascade-linked synthetic-wavelength digital holography (MCL-SW-DH) using an optical frequency synthesizer (OFS) is a promising method to meet this requirement, the slow switching of multiple optical wavelengths in the OFS prevents rapid imaging. In the work described in this article, a line-by-line spectral-shaped electro-optics-modulator-based optical frequency comb (EOM-OFC) is used as a light source in MCL-SW-DH to achieve rapid image acquisition. While MCL-SW-DH enables surface topography measurement with millimeter-order axial range and micrometer-order axial resolution, the line-by-line spectral-shaped EOM-OFC extracts a single narrow-linewidth OFC mode from the 10 GHz-spacing EOM-OFC at a center wavelength of 1545 nm within a spectral range of 30 nm at an interval of 500 ms. The effectiveness of the proposed MCL-SW-DH was highlighted by performing surface topography measurement with four step differences of sub-millimeter to millimeter size with an axial uncertainty of 2.08 µm in the image acquisition time of several seconds. The proposed MCL-SW-DH will be a powerful tool for 3D imaging with a wide axial range and high axial resolution.

中文翻译：

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使用逐行谱形光学频率梳的多级联动合成波长数字全息术

在表面形貌测量和生物医学成像领域，广轴范围3D成像需要没有相位包裹歧义性的相位成像。尽管使用光频率合成器（OFS）的多级联动合成波长数字全息（MCL-SW-DH）是满足此要求的一种有前途的方法，但是OFS中多个光波长的缓慢切换会阻止快速成像。在本文所述的工作中，基于行的谱形基于电光调制器的光学频率梳（EOM-OFC）被用作MCL-SW-DH中的光源，以实现快速的图像采集。虽然MCL-SW-DH可以进行毫米级轴向范围和微米级轴向分辨率的表面形貌测量，逐线谱形EOM-OFC在30 nm光谱范围内以500 ms的间隔从中心频率1545 nm的10 GHz间隔EOM-OFC提取单个窄线宽OFC模式。建议的MCL-SW-DH的有效性通过在几秒钟的图像采集时间内执行亚毫米级至毫米级四个步长差，轴向不确定度为2.08 µm的表面形貌测量中得到了强调。拟议的MCL-SW-DH将成为3D成像的强大工具，具有宽的轴向范围和高的轴向分辨率。建议的MCL-SW-DH的有效性通过在几秒钟的图像采集时间内执行亚毫米级至毫米级四个步长差，轴向不确定度为2.08 µm的表面形貌测量中得到了强调。拟议的MCL-SW-DH将成为3D成像的强大工具，具有宽的轴向范围和高的轴向分辨率。建议的MCL-SW-DH的有效性通过在几秒钟的图像采集时间内执行亚毫米级至毫米级四个步长差，轴向不确定度为2.08 µm的表面形貌测量中得到了强调。拟议的MCL-SW-DH将成为3D成像的强大工具，具有宽的轴向范围和高的轴向分辨率。