Research of coherent noise suppression method based on rotational scatterer in dual-wavelength holographic microscopy

Abstract

Laser light source is widely used in digital holography as a strongly coherent light source, its strong correlation will also introduce some unavoidable coherent noise to the system and affect the imaging quality. This paper proposes a method to suppress system noise by adding a rotational scatterer to the reflective dual-wavelength digital holographic microscope. In this paper, the magnification of the system is calibrated with the 1951 USAF resolution target. A one-dimensional micro- and nano-grid is used to determine the system resolution. By comparing the hologram reproduction results under the same experimental conditions both with and without a rotational scatterer, it is demonstrated that the addition of a rotational scatterer can effectively suppress the coherent noise of this system. The system is also verified to have certain stability through the experiments of repeatability measurement and multi-position measurement on the chip. Furthermore, this research offers a fresh measuring approach for microchannel detection in opaque chips.