A dual bandpass filter is a type of optical filter that allows only two specific wavelength ranges of light to pass through, while blocking or attenuating other wavelengths. In this case, a dual bandpass filter with center wavelengths of 660nm and 890nm would allow light within those two ranges to pass through, while blocking or attenuating light of other wavelengths.

Coligh’s standard dual bandpass 660nm + 890nm  NIR filter:

• Type: dual bandpass filter
• Angle of incidence: 0°
• Center wavelength: 660nm+/-10nm, 890nm+/-10nm
• FWHM: 660nm@25nm & 890nm@35nm
• Thickness: 1.0mm, 1.1mm, 0.5mm, 0.7mm
• Surface quality: 80/50, 60/40
• Size: smaller than 100*100mm

Custom option:

• 550nm+850nm, 475nm+850nm or other wavelength client request
• Working wavelength: according to client’s request
• Material and thickness: according to client’s request
• Surface quality: 40/20 is in option
• Size: Any size round or square smaller than 100*100mm