Off-axis holographic multiplexing involves capturing several complex wavefronts, each encoded into off-axis holograms with different interference fringe orientations, simultaneously, with a single camera acquisition. Thus, the multiplexed off-axis hologram can capture several wavefronts at once, where each one encodes different information from the sample, using the same number of pixels typically required for acquiring a single conventional off-axis hologram encoding only one sample wavefront. This gives rise to many possible applications, with focus on acquisition of dynamic samples, with hundreds of scientific papers already published in the last decade. These include field-of-view multiplexing, depth-of-field multiplexing, angular perspective multiplexing for tomographic phase microscopy for 3-D refractive index imaging, multiple wavelength multiplexing for multiwavelength phase unwrapping or for spectroscopy, performing super-resolution holographic imaging with synthetic aperture with simultaneous acquisition, holographic imaging of ultrafast events by encoding different temporal events into the parallel channels using laser pulses, measuring the Jones matrix and the birefringence of the sample from a single multiplexed hologram, and measuring several fluorescent microscopy channels and quantitative phase profiles together, among others. Each of the multiplexing techniques opens new perspectives for applying holography to efficiently measure challenging biological and metrological samples. Furthermore, even if the multiplexing is done digitally, off-axis holographic multiplexing is useful for rapid processing of the wavefront, for holographic compression, and for visualization purposes. Although each of these applications typically requires a different optical system or processing, they all share the same theoretical background. We therefore review the theory, various optical systems, applications, and perspectives of the field of off-axis holographic multiplexing, with the goal of stimulating its further development.

中文翻译：

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用于快速波前采集和处理的离轴数字全息复用

离轴全息复用涉及捕获多个复杂的波前，每个波前都编码为具有不同干涉条纹方向的离轴全息图，同时使用单个相机采集。因此，多路复用离轴全息图可以一次捕获多个波前，其中每个波前编码来自样本的不同信息，使用的像素数量通常与获取仅编码一个样本波前的单个常规离轴全息图所需的像素数相同。这产生了许多可能的应用，重点是动态样本的获取，在过去十年中已经发表了数百篇科学论文。这些包括视野多路复用、景深多路复用、用于 3-D 折射率成像的断层相位显微镜的角度透视多路复用，多波长复用，用于多波长相位展开或光谱，使用合成孔径进行超分辨率全息成像，同时采集，通过使用激光脉冲将不同的时间事件编码到并行通道中，对超快事件进行全息成像，测量琼斯矩阵和双折射从单个多路全息图中提取样品，并一起测量多个荧光显微镜通道和定量相位分布等。每一种多路复用技术都为应用全息技术有效测量具有挑战性的生物和计量样品开辟了新的视角。此外，即使以数字方式进行多路复用，离轴全息多路复用对于波前的快速处理、全息压缩、并用于可视化目的。尽管这些应用中的每一个通常都需要不同的光学系统或处理，但它们都具有相同的理论背景。因此，我们回顾了离轴全息复用领域的理论、各种光学系统、应用和前景，以刺激其进一步发展。