Speckle suppression in digital in-line holographic microscopy through liquid crystal dynamic scattering

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Materials Science

Background:

• Speckle noise is a significant artifact in coherent imaging systems, degrading image quality and resolution.
• Traditional speckle reduction techniques often involve bulky mechanical components or complex setups.
• In-line holographic imaging offers high resolution but is susceptible to coherent noise.

Purpose of the Study:

• To demonstrate speckle noise reduction in an in-line holographic imaging system.
• To introduce a compact and active speckle suppression method using a liquid crystal dynamic scatterer (LCDS).
• To evaluate the performance of the LCDS in enhancing image resolution and simplifying the imaging system.

Main Methods:

• Integration of a zwitterion-doped liquid crystal dynamic scatterer (LCDS) cell into a minimally modified bright-field microscope.
• Active modulation of spatial coherence by the LCDS to suppress coherent artifacts.
• Quantitative performance evaluation using phase and amplitude test targets and a biological sample.

Main Results:

• Significant reduction in speckle noise was achieved in the in-line holographic imaging system.
• Enhanced image resolution and preservation of overall system simplicity were observed.
• The LCDS method demonstrated versatility and effectiveness on various targets, including biological samples.

Conclusions:

• The zwitterion-doped LCDS cell is an effective solution for speckle noise reduction in holographic imaging.
• The proposed method offers a compact, vibration-free alternative to traditional speckle suppression techniques.
• The approach is adaptable to other imaging modalities requiring speckle reduction.