News | March 6, 2015

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 m

Other mid/long-wave infrared (M/LWIR) filters are also available for standard gas absorption lines including CH4 (3.46mm or 7.73mm), CO (4.67mm), CO2 (9.4mm), H2O (2.72mm), O3 (9.0mm) and N2O (7.73mm). 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. Please contact us directly to discuss these or any optical filter needs.

About Iridian Spectral Technologies Ltd (Iridian) – Ottawa, ON, Canada
Iridian is a diversified optical filter manufacturer that is an international leader in filter design and manufacture especially for application in the fields of fiber optic communications, optical spectroscopy, 3D entertainment, and in aerospace. Iridian was ranked as one of the top 150 high technology companies in Canada in the 2011 and 2012 Branham300 rankings and won the 2010 Canada Export Achievement Award for the province of Ontario sponsored by Profit magazine together with Export Development Corporation (EDC). Iridian is a global supplier with distributors in many countries particularly in Asia. For more information, visit

Source: Iridian Spectral Technologies

Iridian Spectral Technologies