A 390nm optical bandpass filter with a full width at half maximum (FWHM) of 20nm is a type of optical filter that allows only a narrow range of wavelengths centered around 390nm to pass through while blocking out other wavelengths. The FWHM of 20nm indicates that the filter has a relatively narrow passband.

This type of filter can be used in a wide range of applications, including:

Fluorescence microscopy, Spectroscopy, Astronomy and UV curing

Coligh’s stock standard 390nm optical bandpass filter feature:

• Feature: UV bandpass filter
• Center wavelength：390±5nm
• Angle of incidence: 0°
• FWHM: 20nm±5nm
• Blocking range: 200-1100nm
• Blocking depth: OD4, OD5, OD6, OD8
• Transmission average: Above 90%
• Thickness：1.0mm, 1.1mm
• Size: φ8mm, φ10mm, φ12.5mm, φ25.4mm, φ50mm mounted or unmounted

Custom option:

• Bandwidth: 10nm, 25nm, 40nm or any other bandwith client request
• Angle of incidence: Depend on request
• Blocking depth: Deep less than OD8
• Size: round or square smaller than 100*100mm
• Material thickness: Depend on request
• Transmission and blocking rang: custom as per requirement or between 200nm to 1500nm