Characterization of color cross-talk of CCD detectors and its influence in multispectral quantitative phase imaging

TL;DR

This paper investigates the color crosstalk in CCD detectors used in multispectral quantitative phase imaging, revealing its impact on measurement accuracy and proposing a new measurement approach without prior camera specifications.

Contribution

The study introduces a novel method for accurately measuring color crosstalk in 2D detectors and compares its effects on QPI performance across different CCD camera types.

Findings

Color crosstalk affects fringe width and visibility in multispectral imaging.

Presence of crosstalk causes non-uniform background errors.

Crosstalk limits phase measurement accuracy in multispectral QPI.

Abstract

Multi-spectral quantitative phase imaging (QPI) is an emerging imaging modality for wavelength dependent studies of several biological and industrial specimens. Simultaneous multi-spectral QPI is generally performed with color CCD cameras. However, color CCD cameras are suffered from the color crosstalk issue, which needed to be explored. Here, we present a new approach for accurately measuring the color crosstalk of 2D area detectors, without needing prior information about camera specifications. Color crosstalk of two different cameras commonly used in QPI, single chip CCD (1-CCD) and three chip CCD (3-CCD), is systematically studied and compared using compact interference microscopy. The influence of color crosstalk on the fringe width and the visibility of the monochromatic constituents corresponding to three color channels of white light interferogram are studied both through simulations and experiments. It is observed that presence of color crosstalk changes the fringe width and visibility over the imaging field of view. This leads to an unwanted non-uniform background error in the multi-spectral phase imaging of the specimens. It is demonstrated that the color crosstalk of the detector is the key limiting factor for phase measurement accuracy of simultaneous multi-spectral QPI systems.