High‐Throughput Optical Imaging and Spectroscopy of One‐Dimensional Materials

Direct visualization of one‐dimensional (1D) materials under an optical microscope in ambient conditions is of great significance for their characterizations and applications. However, it is full of challenges to achieve such goal due to their relative small size (ca. 1 nm in diameter) in the optical‐diffraction‐limited laser spot (ca. 1 μm in diameter). In this Concept article, we introduce a polarization‐based optical homodyne detection method that can be used as a general strategy to obtain high‐throughput, real‐time, optical imaging and in situ spectroscopy of polarization‐inhomogeneous 1D materials. We will use carbon nanotubes (CNTs) as an example to demonstrate the applications of such characterization with respect to the absorption signal of individual nanotubes, real‐time imaging of individual nanotubes in devices, and statistical structure information of nanotube arrays.