I'm working on an experiment that have visible spectrum light source (RGB LED at e.g. 495–570 nm wavelength), holder with sample, narrow bandpass filter (eg: CWL:520nm, FWHM:5nm) and a photodiode to detect the signal. As light source is RGB LED I can easily change it's wavelength but simultaneously I also have to change bandpass filter (different filter for different wavelength).
Now problem is every time I have to replace filter according to light source wavelength which is not right way and these filters are costly too.
Is there any alternative for these bandpass filter?