Noise suppression using quasi-phase conjugation in digital holographic microscopy

Various approaches for generating phase-conjugate signal have been recently proposed that exploit the advantage of noise suppression in digital holographic microscopy (DHM). This study presents a reproducible method for generating a time-independent quasi-phase conjugated signal, which is simple, compact, and cost-effective in a linear medium. Used in conjunction with adaptive optics or conventional phase conjugation technique, our method suppresses the influence of diffraction and has less constraint on wavelength and polarization state. Such a configuration generates quasi-phase conjugated signal in real time and supports multi-wavelength input simultaneously. The optical system produces images of high magnification and high resolution of 228.1 line pairs per mm (i.e. 2. 19 μ m ) and has low spatial standard deviation of 0.2 nm. In addition, scattering noise of 15 degrees diffusing angle from object is suppressed effectively.