Question

The expression of resolving power of a microscope is inversely proportional to the wavelength \[\lambda\] used to illuminate the object. Can we have a source with a very small wavelength compared to that of visible light?

Answer 1

Yes. Sources of ultraviolet, X-rays and gamma rays have wavelengths much smaller than visible light. Since the resolving power of a microscope increases as the wavelength decreases, shorter-wavelength radiation can improve resolution. However, ultraviolet and X-rays may damage specimens and require special optical systems; therefore, their use is limited. Electron microscopes use electrons having very small de Broglie wavelengths and provide still higher resolution.