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Standard infrared bandpass filters

from Andover

Bandpass filters isolate specific regions of the spectrum, simultaneously providing high transmission of desired energy, and deep rejection of unwanted energy. Available in wide or narrow bandwidths, they can be tailored to suit your specific requirements.

Constructed of hard, durable first-surface dielectric coatings on optical-quality IR-transmitting substrates, these filters will withstand normal cleaning and handling associated with any high-quality optical component.

Features

Useful for isolating narrow spectral regions
Constructed of hard, durable first-surface coatings
Available in standard and custom wavelengths up to 14µm
Filters offered in 25mm dia, but custom sizes, shapes and optical characteristics available

Specifications

General Specifications
Diameter Tolerance	+0/-0.1 mm
Min. Clear Aperture	21 mm Dia.
Transmission (Typ.)	60-80%
Blocking	T < 0.1% Average to 30 µm
24-hour Humidity	per MIL-C-48497A
Moderate Abrasion	per MIL-C-48497A
Adhesion	per MIL-C-48497A
Optional	Mounted in threaded ring - contact our expert on the right for thread sizes

Standard IR gas analysis bandpass filters

Gas	Center W/L	Bandwidth	Part Number
Water Vapor	2.70 ± 0.03 µm 2.95 ± 0.03 µm	120 ± 30 nm 130 ± 30 nm	2.70GA05-25 2.95GA05-25
Methane and Ethanol	3.46 ± 0.04 µm	140 ± 30 nm	3.46GA05-25
Formaldehyde	3.60 ± 0.04 µm	140 ± 30 nm	3.60GA05-25
CO₂	4.26 ± 0.04 µm	120 ± 30 nm	4.26GA05-25
CO	4.67 ± 0.05 µm	150 ± 30 nm	4.70GA05-25
NO	5.30 ± 0.05 µm	420 ± 50 nm	5.30GA05-25
SWIR	4.00 ± 0.20 µm	2000 ± 200 nm	4.00GA20-25
FIR Broadband	10.0 ± 0.20 µm	4000 ± 200 nm	10.00GA40-25
CO₂	10.6 ± 0.10 µm	420 ± 100 nm	10.60GA15-25

Custom IR Bandpass Filters

Andover can design and fabricate custom bandpass filters to suit your particular requirements. Every phase of the process is performed in-house, including thin-film coating design, mechanical design, substrate fabrication and polishing, coating, inspection and environmental testing.

We can coat a variety of substrate materials, including Germanium, Sapphire, Silicon, Calcium Fluoride, Zinc, Sulfide and Zinc Selenide. Contact our expert on the right for a quotation, whether it is for prototype quantities or production quantities.

Custom IR Bandpass Filter Specifications

Custom spectral and physical properties available upon request

Bandwidth (% of CW/L)	W/L Range	Transmission (Typ.)	Blocking	Part Numbers
>10%	2.4 µm - 5.0 µm 5.1 µm - 6.5 µm 6.6 µm - 8.5 µm 8.6 µm - 10.3 µm 10.4 µm - 14.0 µm	70-80% 70-80% 60-70% 60-70% 50-60%	0.3 to 40 µm 0.3 to 15 µm 0.3 to 15 µm 0.3 to 15 µm 0.3 to 15 µm	IRFC10-25 IRFC12-25 IRFC14-25 IRFC16-25 IRFC18-25
1.5-10%	2.4 µm - 5.0 µm 5.1 µm - 6.5 µm 6.6 µm - 8.5 µm 8.6 µm - 10.3 µm 10.4 µm - 14.0 µm	70-80% 70-80% 60-70% 60-70% 50-60%	0.3 to 40 µm 0.3 to 15 µm 0.3 to 15 µm 0.3 to 15 µm 0.3 to 15 µm	IRFC20-25 IRFC22-25 IRFC24-25 IRFC26-25 IRFC28-25