Digital holographic microscopy

Fig. 1 Intensity variation along the depth (z) of reconstructed volume near the in-focus position (z ,i ) of a particle (diameter = dp) image reconstructed using lensiess digital holography and digital holographic microscopy...

The effective numerical aperture (A Aeff) of the digital holographic microscopy system is used for the determination of transverse and longitudinal size of the reconstructed particle image. The diffraction limit S of the optical system is calculated as (5 = 1.22(/(/AMeff). If dp < 5, the particle imaging is diffraction limited and transverse size of particle image dj pi equals d, i.e.,... 

The key research findings which have appeared on the application of DHM to microfluidics are as follows The digital holographic microscopy for flow measurements in a microchannel has been implemented in Ref. [9]. The effect of the different experimental parameters (i.e., magnification, particle concentration, depth of the measurement volume) on the DHM results was reported in Ref. [7]. DHM was applied later to measurement of a turbulent boundary layer [10]. The DHM was successfully applied to measurement of flow field in a T-shaped micro-mixer [5], and the results were presented using 3D vorticity structures. 

Digital holographic microscopy (DHM) is a promising tool to carry out three-dimensional flow field measurements at microscale. The implementation of DHM-based PIV/PTV technique can facilitate the design and understanding of various lab-on-chip devices. 

Ooms T, Lindken AR, Westerweel J (2009) Digital holographic microscopy applied to measurement of a flow in a T-shaped micromixer. Exp Fluids 47 941-955... 

Digital holographic microscopy (DHM) can be utilized noninvasively to study changes in the cells of living tissue subjected to simulated microgravity. Information is captured by a digital camera and processed by software. 

Abbott AP, Azam M, Ryder KS, Saleem S (2013) In situ electrochemical digital holographic microscopy a study of metal electrodeposition in deep eutectic solvents. Anal Chem 85(14) 6653-6660. doi 10.1021/ac400262c... 

Depth of Field The depth of measurement volume is decided by depth of field of digital holographic microscope. In digital holography, the depth of field is equal to the depth of the measurement volume unlike conventional microscopy in which depth of field is inversely proportional to the magnification of the objective lens. 

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