Hi, I have a question about using EM to resolve images. I know that resolving power is constrained by Rayleigh's Criterion. Consider a setup where a normal incandescent light bulb is mounted 1ft. above a desktop. A penny is hung directly below the light bulb 10cm from its surface. We know that a penny looks perfectly circular to the naked eye, but we want to measure any variation that shows that it is not a perfect circle, due to manufacturing limitations or whatever. Because the light bulb's light diffracts when it strikes the penny's surface, the image we see on the desktop has 'blurry' edges due to this diffraction. This blurriness (correct me if I'm wrong) comes from the fact that the light bulb's light is sinusoidal in addition to the limits implied from the emitted wavelength, as per Rayleigh's Criterion. But what if we replaced the light bulb with an apparatus that shines light comprised of a square waveform instead of a sinusoidal waveform. Would the image of the penny on the desktop have less 'blurry', finer resolved edges? Thanks.