A normal bright-field microscope may be updated with coherent sensing capabilities easily, inexpensively, and compactly using phase imaging microscopy in the Gabor regime. The digital sensor records an in-line Gabor hologram of the target sample by incorporating coherent illumination into the regular microscope embodiment, generated by a small defocus distance of the sample at the input plane. This hologram is then numerically post-processed to obtain the quantitative phase information of the sample. However, when dealing with Gabor's regime, coherent noise and twin-image disturbances affect the recovered phase distribution. In this contribution, we describe a single-shot method for reducing these two error sources based on wavelength multiplexing. The sample is illuminated by a multi-wavelength laser source that utilized three diode lasers, and the wavelength-multiplexed Gabor hologram is to be captured on a digital color sensor using a traditional RGB color camera in a single exposure. The presented phase imaging method is completed by the implementation of a new algorithm built on a modified Gerchberg-Saxton kernel to obtain an enhanced quantitative phase image of a sample that has been improved in terms of coherent noise removal and twin-image reduction. Complex field filtering in terms of hologram's imaginary and real part numerical alteration is in place in an iterative fashion. Experimental validations are carried out in a off-the-shelf Olympus BX-60 upright microscope with a 20X 0.46NA objective lens employing static (resolution test targets) and dynamic (live spermatozoa) phase sample quantitative imaging.
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