Electronic Theses and Dissertations

Date

2022

Document Type

Thesis

Degree Name

Master of Science

Department

Electrical & Computer Engineering

Committee Chair

Ana Doblas

Abstract

Digital holographic microscopy (DHM) provides Quantitative phase images (QPI) significant when imaging transparent (e.g., biological) samples. This method of imagining requires no damage to the sample due to toxic, chemical staining, leading to a non-invasive and label-free technique. Common-path DHM systems, which are based on self interference, are usually more robust than double-path DHM systems (based on Mach-Zehnder and Michelson configurations), being less exposed to external fluctuations. Common-path DHM systems usually require fewer optical elements which reduce the cost of the system. In this work, a 3D-printed common-path DHM system using a Fresnel biprism has been design and evaluated using both a star and USAF target samples from Benchmark Technologies. A common issue in these DHM systems is that the self-interference causes an overlay between the two sample’s images. Therefore, common-path DHM systems are restricted for dense biological and material science samples, limiting their use for only imaging sparse samples. To resolve the overlay issue in common-path systems, one can reduce the sample’s field of view using half of the imaging area or insert a spatial filter. In this work, we have also implemented two DHM systems that employ an optical pinhole to spatial filter one of the samples’ image replicas. The optimal pinhole size is evaluated by analyzing the frequency content of the reconstructed phase images of a transmissive star target.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest.

Notes

Open access

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