IRF-Se Series Chalcogenide Long-wave Infrared (LWIR) Fiber (1.5 to 10µm)

IRF-Se fiber

Chalcogenide glass is based on the chalcogen elements (sulfur, selenium and tellurium) with the addition of other elements such as arsenic, antimony, or germanium).  It offers promising properties such as transmission in mid and far infrared regions of spectra, lower values of phonon energies, high refractive index and very large nonlinearities as compared to silica. Chalcogenide glass fibers are the ideal candidates for mid-infrared applications that require high power laser delivery, chemical sensing, thermal imaging and temperature monitoring.

IRflex’s IRF-Se Series long-wave infrared (LWIR) fiber, made from extra high purity chalcogenide glass As2Se3, is specially designed and manufactured to generate and/or guide mid-infrared wavelengths from 1.5 to 10µm with high transmission efficiency and nonlinearities about 1000 times that of silica glass fiber.

IRF-Se-100 multimode LW mid-IR fiber has transmission range from 1.5 to 8µm, with minimum loss of 0.29 dB/m at 3.95µm wavelength.

IRF-Se-100 (R&D) multimode LW mid-IR fiber has broadest transmission range from 1.5 to 10µm wavelength, with 0.58 dB/m minimum optical loss at 5.98µm wavelength.

IRF-Se-300 multimode LW mid-infrared fiber has transmission range from 1.5 to 9.7µm, with minimum optical loss of 0.21dB/m at 2.59µm. This fiber is initially designed to use with medical surgery laser.

IRF-Se-12 singlemode LW mid-infrared fiber has transmission range from 1.5 to 9.7µm, with minimum optical loss of 0.32 dB/m at 2µm wavelength. This step-index LWIR fiber has a core of 12µm diameter, NA of 0.47 and core refractive index of 2.7.  The fiber is truly singlemode for wavelength larger than 7.4µm cutoff.  This single-mode longwave mid-infrared fiber can be used for direct transmission or supercontinuum generation in the long wave mid-infrared.

All the fibers are commercially available and can be sold as bare fiber or terminated with connectors.

The standard fiber cables are terminated with stainless steel ferrules, FC/PC, FC/APC or SMA905 connectors.  IRflex's FC/B® connector - the FC connector at Brewster Angle enables perfect coupling without reflection with polarized laser beam, is also available upon request.

The protective jacket can be stainless steel, stainless steel with PVC sheathing or clear FEP sheathing, PVDF and PVC.

Other different cable assembling configurations are offered upon request.


  • Low loss
  • Broad transmission range from 1.5 to 10µm
  • High power handling strength
  • High mechanical flexibility


  • MID-IR laser beam delivery
  • IR spectroscopy
  • Chemical sensing
  • Scientific and medical diagnostics IR-imaging system
  • Nonlinear supercontinuum generation


IRF-Se Series IRF-Se-100 (R&D) IRF-Se-100 IRF-Se-300 IRF-Se-12
Core Diameter (µm) 100 100 300 12
Clad Diameter (µm) 170 170 370 170
Protective Coating Diameter (µm) 330 330 550 330
Core/Clad Structure As2Se3 As2Se3 As2Se3 As2Se3
Transmission Range (µm) 1.5 to 10 1.5 to 8
1.5 to 9.7 1.5 to 9.7
Core Refractive Index 2.7 2.7 2.7 2.7
NA 0.271 0.275 0.3543 0.47