MWIR Filters for Photoacoustic Spectroscopy


The desire to accurately identify, measure, and monitor environmental and process gases in fields as diverse as agriculture, automotive, medicine, and petrochemicals has driven increased demands for Photoacoustic Spectroscopy (PAS). Key to the function of PAS devices and gas monitors is highly monochromatic illumination of the sample cell, ensuring that only light corresponding to the absorption band of the gas of interest is present. Iridian’s family of narrow, mid-wave infrared (MWIR), gas band-pass filters (BPF) are perfectly suited to meet this need in both single and multi-wavelength detection systems.

Iridian’s MWIR BPF have been designed to optimize detection of narrow spectral emission lines and are deposited using energetic sputtering processes, making them very reliable and resistant to damage or change in performance, both in use and when being processed from wafer to final size format.

Example CO2: BPF 4260 – 120, Iridian Part Number: BCR000008

Key Features include:

  • Substrate: Silicon
  • Diameter: 25.4 mm + 0 / – 0.1 mm
  • Reliability and durability as per MIL-C-48497A
  • RoHS compliant
  • Center Wavelength: 4260 nm +/- 21.3 nm
  • FWHM Bandwidth: 120 nm
  • Peak transmission: > 80%
  • Blocking range > OD3 (< 0.1%): 1 – 10 μm

Other mid/long-wave infrared (M/LWIR) filters are also available for standard gas absorption lines including CH4 (3.46μm or 7.73μm), CO (4.67μm), CO2 (9.4μm), H2O (2.72μm), O3 (9.0μm) and N2O (7.73μm). Additionally, Iridian offers custom tailored filters to meet specific customer requirements for spectral performance or size.

Iridian’s well-established energetic sputtering technology has enabled these filters to be offered at economical prices while providing extreme durability and superior optical performance. These online offerings leverage Iridian’s industry leading capabilities in design and manufacture of optical filters to further address the growing needs for readily available IR sensing filters.


Contact Us Directly

Additional Resources

Contact Us

Tel:  +1 (613) 741-4513
Fax: +1 (613) 741-9986


View Our Catalog

Buy Online

Purchase from our online store or place a custom order.

Send Us an Enquiry