We implement differential interference contrast (DIC) microscopy using high-speed synthetic aperture imaging that expands the passband of coherent imaging by a factor of 2.2. For an aperture synthesized coherent image, we apply for the numerical post-processing and obtain a high-contrast DIC image for arbitrary shearing direction and bias retardation. In addition, we obtain images at different depths without a scanning objective lens by numerically propagating the acquired coherent images. Our method achieves high-resolution and high-contrast 3-D DIC imaging of live biological cells. The proposed method will be useful for monitoring 3-D dynamics of intracellular particles.
We propose a method based on wavefront shaping for enhancing the backscattered light detected from any location in a
sample medium, using low-coherence interferometry. The lateral phase profile of the light incident upon the sample is
controlled using a spatial light modulator (SLM). In this manner, we apply an orthogonal set of phase masks to the
illumination (input) and measure the backscattered signal response (output). These measurements permit us to determine
the linear transformation between the input complex-amplitude modulation profile and the output time-resolved signal.
Thus, we can determine the appropriate SLM write pattern for maximizing the detected signal for a given optical time
delay (in the sample arm). In this manuscript, we are interested in the degree to which maximizing this signal also
permits us to localize the three-dimensional sample region from which the backscattered signal is derived.