IR Optics Infrared Optics IR Filter Infrared Filter

IR Longpass Filters

Infrared (IR) longpass filters transmit light higher than the cut-on wavelengths and attenuate the shorter wavelengths. The IR longpass filters are popularly used in spectroscopy, thermography, and metrology & device Engineering.


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Part NumberDia (mm)Cut-on λ (nm)Blocking λ (nm)Transmitting λ (nm)T (%)
LFIR-1.05-125.41050200-10501060-12000> 80
LFIR-1.5-125.41500200-15001510-12000> 80
LFIR-1.75-125.41750200-17501760-12000> 80
LFIR-2-125.42000200-20002010-12000> 80
LFIR-2.5-125.42500200-25002510-12000> 80
LFIR-3-125.43000200-30003010-12000> 80
LFIR-3.5-125.43500200-35003510-12000> 80
LFIR-4-125.44000200-40004010-12000> 80
LFIR-4.5-125.44500200-45004510-12000> 80
LFIR-5-125.45000200-50005010-12000> 80
LFIR-5.5-125.45500200-55005550-12000> 80
LFIR-6-125.46000200-60006020-12000> 80
LFIR-6.5-125.46500200-65006520-12000> 80
LFIR-7-125.47000200-70007050-12000> 80
LFIR-7.5-125.47500200-75007550-12000> 80
LFIR-8-125.48000200-80008030-12000> 80
LFIR-8.5-125.48500200-85008520-12000> 80
LFIR-9-125.49000200-90009050-12000> 80
LFIR-9.5-125.49500200-95009550-12000> 80
LFIR-10-125.410000200-1000010000-12000> 80
LFIR-10.5-125.410500200-1050010550-12000> 80
LFIR-11-125.411000200-1100011050-12000> 80
LFIR-11.5-125.411500200-1150011520-12000> 80

IR Filter Diagram 3Diameter Tolerance: +0/-0.2mm
Clear Aperture: >80%
Thickness: <10mm
Cut-on Tolerance: ±2nm
Cut-off Tolerance: ±2nm
Peak Transmission: >70-80%
Block: <0.1%
CWL Shift: <0.02nm/℃

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