An apparatus and a method for optically analyzing a sample are provided. The apparatus includes a first optical device that transmits a narrow waveband of light and has a first filter and a first monochromator that provide different paths for the narrow waveband of the light. The apparatus may also include a light source that generates the light as broadband excitation light, in which case the first optical device transmits a narrow waveband of the broadband excitation light through the first filter or the first monochromator. Further, the apparatus may include a second optical device that directs the narrow waveband of the broadband excitation light onto the sample and receives emission light from the sample, a third optical device that transmits a narrow waveband of the emission light, and a detector that converts the narrow waveband of the emission light into an electrical signal.