Autofocus of imaging ellipsometry.

Area of Science:

• Optical microscopy
• Biophysics
• Biosensing

Background:

• Imaging ellipsometry uses polarized light for microscopic study of semitransparent biological cells.
• Applications include marker-free, non-destructive disease diagnosis.
• Fast measurements are crucial for environmentally sensitive living cells, making accurate focal plane location vital for biosensing.

Purpose of the Study:

• To develop an efficient and robust method for locating the focal plane in imaging ellipsometry.
• To improve the speed and accuracy of focal plane determination for biosensing applications.
• To present a sample-independent focal plane detection technique.

Main Methods:

• Analysis of through-focus ellipsometry images of S. mutans cells on Au film.
• Development of an edge detection algorithm for identifying cell boundaries.
• Comparison with threshold-dependent methods like Laplace filtering.

Main Results:

• An efficient method for focal plane position locating was identified through cell edge detection in ellipsometry images.
• The edge detection method is sample-independent and robust against noise and image shifts.
• The method is user-friendly, requiring no threshold value selection.

Conclusions:

• Cell edge detection in ellipsometry images provides an efficient, robust, and user-friendly approach to focal plane localization.
• This method is not sample-dependent, enhancing its applicability in biosensing.
• The technique holds significant potential for advancing biosensing applications requiring fast and accurate imaging.