Phase Contrast Microscopy

This lecture covers the principles and applications of phase contrast microscopy, a technique developed by Frits Zernike in the 1930s to visualize unstained transparent samples with high contrast. It explains how phase differences are transformed into amplitude differences, allowing for label-free imaging. The lecture delves into the optical path length, phase shift, and key concepts of phase-contrast microscopy, such as isolating surround and diffracted waves to enhance image contrast. It also discusses the positive phase contrast technique, where objects with different refractive indices appear dark or bright. The development of phase contrast microscopy revolutionized biological and medical research, earning Zernike the Nobel Prize in Physics in 1953.