Final answer:
Confocal microscopy uses a laser scanning method and pinholes to create high-resolution 3D images by blocking out-of-focus light, enabling detailed observation of live cell processes and thicker specimens.
Step-by-step explanation:
How Light Travels in a Confocal Microscope
In a confocal microscope, light travels uniquely to create high-resolution, three-dimensional images. It uses a laser to scan the sample at multiple focal planes (z-planes). A right pinhole illuminates a tiny region of the sample. Focused light from this region travels through the dichroic mirror and exits through another pinhole to reach a detector and computer. Unwanted, out-of-focus light is blocked by this pinhole system. By scanning the pinhole laterally and vertically, multiple in-focus images from different z-planes are collected and used to reconstruct a 3D image of the specimen.
The confocal system uses pinholes to ensure that only light from the focal plane contributes to the image. As the pinholes are conjugate to the focal points, they exclude out-of-focus light leading to enhanced clarity. The second pinhole, placed before the detector, is vital as it blocks most of the light not emitted from the focal point. Each captured image is stored in a computer, and a full scan results in a detailed 3D image. Thus, confocal microscopy greatly enhances the capability to observe live cell processes and thick specimens with precise detail compared to traditional optical microscopy.