Abstract

The confocal Raman microscope (CRM) is a powerful tool in analytical science. Image quality is the most important performance indicator of CRM systems. The point spread function (PSF) is one of the most useful tools to evaluate the image quality of microscopic systems. A method based on a point-like object is proposed to measure the PSF of CRM, and the size effect of spherical objects is discussed. A series of phantoms are fabricated by embedding different sizes of polystyrene microspheres into polydimethylsiloxane matrix. The diameters of microspheres are from 0.2 µm to 5 µm. The phantoms are tested by measuring the PSF of a commercial CRM whose nominal lateral resolution is about 1 µm. Results of the PSF are obtained and the accuracy of resolution is used to evaluate the size effect of the microspheres. Experimental results are well consistent with theoretical analysis. The error of the PSF can be decreased by reducing the diameter of the microsphere but meanwhile the signal-to-noise ratio (S/N) will be lowered as well. The proper diameter of microspheres is proposed in consideration of the trade-off between the S/N and the measurement error of the PSF. Results indicate that the method provides a useful approach to measurement of the PSF and the resolution of the CRM.

© 2020 The Author(s)

Optimized pupil-plane filters for confocal microscope point-spread function engineering

M. A. A. Neil, R. Juškaitis, T. Wilson, Z. J. Laczik, and V. Sarafis
Opt. Lett. 25(4) 245-247 (2000)

Measurement of the point spread function in the ocean

Kenneth J. Voss and Albert L. Chapin
Appl. Opt. 29(25) 3638-3642 (1990)

Realistic modeling of the illumination point spread function in confocal scanning optical microscopy

Michael J. Nasse and Jörg C. Woehl
J. Opt. Soc. Am. A 27(2) 295-302 (2010)

Effect of point-spread functions on precision edge measurement

Raymond G. White and Robert A. Schowengerdt
J. Opt. Soc. Am. A 11(10) 2593-2603 (1994)

Point spread function of the polarized light field microscope

Mai Thi Tran and Rudolf Oldenbourg
J. Opt. Soc. Am. A 39(6) 1095-1103 (2022)