520nm Bandpass Filter

Use CWL 520nm with 10nm FWHM for 520nm direct-emission green laser diode line selection, source cleanup, or detector-side isolation.

520nm is commonly produced by direct-emission green laser diodes rather than frequency-doubled Nd:YAG lasers. For laser-line filtering, the key specs are CWL match, FWHM, transmission at 520nm, and OD blocking across the unwanted wavelength range.

Use CWL 520nm with 20–40nm FWHM for green LED illumination, source cleanup, or practical green-band output.

Green LEDs have broader emission than laser sources. A 20nm FWHM filter can provide more defined green-band control, while 40nm FWHM is more practical when the setup needs stronger illumination or camera-side brightness.

Use CWL near 520nm with 20–40nm FWHM when collecting green fluorescence emission from GFP/EGFP/FITC/Alexa Fluor 488-type signals.

For fluorescence microscopes, flow cytometers, or fluorescence detection systems, the 520nm filter is usually placed before the detector, camera, PMT, or spectrometer input. The goal is to collect the green emission band while reducing excitation leakage and nearby background.

Use CWL 520nm with 10–20nm FWHM before a silicon photodiode, CMOS/CCD camera, PMT, or spectrometer input when the target signal is near 520nm.

For detector-side filtering, the filter improves signal-to-background ratio by passing the 520nm signal and reducing unwanted background outside the target band. Use 10nm FWHM for stronger 520nm isolation, or 20nm FWHM when more signal level is needed.

Use CWL 520nm with 20–40nm FWHM for green LED machine vision, surface inspection, or camera-based contrast imaging.

For imaging systems, the filter helps isolate the green illumination band and reduce unwanted ambient or source background. Use 20nm FWHM for stronger wavelength control, or 40nm FWHM when image brightness and stable contrast are more important.