Fluorescence microscopy requires an intense light source at the specific wavelength that will excite fluorescent dyes and proteins. The traditional method employs a white light, typically from a mercury or xenon arc lamp. Although such broad spectrum lamps can generate ample light at desired wavelengths, only a small percentage of the projected light is useful in any particular application. The other wavelengths must be suppressed to avoid background noise that reduces image contrast and obscures the fluorescent light emissions.

This process of suppressing extraneous light is complex, expensive, and only partially effective: Even after decades of refinements, the best filters are not 100-percent successful at blocking the bleed-through of nonspecific photons. Some mitigation techniques end up not only suppressing peripheral light, but also significantly diminishing the intensity of the desired wavelengths. To address the root cause of the problem—the presence of nonspecific photons—a different approach is necessary

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