Figure 1. The imaging system.

(A) The SLIM set-up is an add-on module to a commercial phase contrast microscope. The first set of lenses (L1 and L2) magnify the image to maintain the resolution of the microscope. The Fourier transform of the image plane is projected by lens L3 onto the spatial light modulator (SLM) where the phase pattern is shifted in phase 4 times, in increments of π/2. The lens L4 Fourier transforms the pattern on the SLM and the final image is recorded onto the CCD and stored on the computer. (B) Four phase shifted images recorded using a 40X/0.75NA objective with the final quantitative phase image shown on the right. Color bars indicate phase values in radians.