Chromatic Aberration Correction for Improved Stimulated Raman Signal

Abstract

Stimulated Raman scattering (SRS) microscopy enables label-free chemical imaging by exploiting the vibrational signatures of molecular bonds, but signal intensity degrades significantly at large field angles due to chromatic aberration in the microscope system.1 This work develops a quantitative characterization pipeline for measuring chromatic focal shift and lateral color aberration across the field of view, using Z-stack imaging of a calibration grid target analyzed in Python. The pipeline was validated by demonstrating its sensitivity to known differences in optical performance between a single achromatic doublet and a Plössl eyepiece configuration. A systematic comparison of over twenty commercial lens configurations was conducted in Zemax OpticStudio, using chromatic focal shift and lateral color as optimization targets. A Plössl eyepiece consisting of two Newport Scientific PAC12AR.16 100 mm achromatic doublets was identified as the strongest candidate for lateral color correction. Experimental validation confirmed the simulation results, with the Newport configuration reducing average lateral color to sub pixel levels at high field angles and producing substantially increased SRS signal uniformity across the field of view compared to the baseline Thorlabs configuration. These results demonstrate that careful optical characterization and commercial lens selection can meaningfully improve SRS microscope performance without requiring custom optics.