Full field vertical scanning in short coherence digital holographic microscope

Area of Science:

• Optical microscopy
• Holography
• Diffractive optics

Background:

• Off-axis digital holography microscopy (DHM) suffers from non-uniform interference contrast and complex vertical scanning due to non-coplanar wavefronts.
• These limitations reduce image quality and increase measurement time for sample topography extraction.

Purpose of the Study:

• To demonstrate significant vertical scanning speed improvement in DHM using a volume diffractive optical element (VDOE).
• To quantitatively analyze noise introduced by VDOEs in phase and intensity images.

Main Methods:

• Implementation of a VDOE in the reference arm of an off-axis DHM setup.
• Fabrication of five identical VDOEs using a standardized procedure.
• Quantitative analysis of noise in phase and intensity images with and without the VDOE.

Main Results:

• Achieved a tenfold improvement in vertical scanning speed.
• VDOEs introduce minor intensity non-uniformity in the reference beam, increasing phase image noise by approximately 20%.
• VDOEs do not impact the temporal noise of extracted phase images.

Conclusions:

• VDOEs effectively enhance DHM performance by enabling faster measurements.
• The minor increase in noise is a manageable trade-off for the substantial speed gains.
• VDOE integration offers a promising approach for more efficient microscopic imaging.