Most fluorescence applications use one of the two designs depicted.

The excitation filter performs two functions:

1) Allowing the transmission of light at wavelengths within the absorptive spectrum of the dye.

2) Rejection of light at wavelengths within the emission spectrum of the dye, which could consequently be reflected by the specimen and incorrectly detected as emission energy

The emission filter has two similar functions:

1) Allowing the transmission of light at wavelengths within the emission spectrum of the dye.

2) Rejection of light at wavelengths within the absorptive spectrum of the dye, which could consequently be incorrectly detected as emission energy.

For best results, select excitation and emission filters with center wavelengths as close to the absorptive and emissive peaks as possible. This gives the best possible yield from the selected dye. Please make a phone-call to SPO tech-engineer staff for your special requirements.