Fibre Comparison

Developments in near and mid infrared fibre optic materials have enabled Fibre Photonics to produce a family of near and mid infrared fibre optic cables, bundles and pigtails.

Based on silver halide polycrystalline infrared (PIR) and chalcogenide infrared (CIR) materials, their spectral range provides optical transmission to match the output from black body sources, LEDs, gas lasers and solid state infrared lasers including Quantum Cascade, Disk, VCSEL and VECSEL types.

Through advanced production techniques, Fibre Photonics can provide ruggedised cables for use in harsh environments with A/R coatings to match your transmission requirements.

Spectral Range

The transmission regions covered by Fibre Photonics infrared cables are as follows:

  • PIR Fibre 3 - 18 mm (550 - 3300cm-1)
  • CIR Fibre 1.5 - 6.0 mm (1650 - 6650cm-1)

This spectral region is of significance in environmental monitoring and chemical analysis, as it covers the fundamental molecular vibrations that comprise the ‘fingerprint region’.

Typical transmission spectra of 1,5m long PIR-900/1000 fibre (red) versus CIR-750/850 fibre (blue) (includes reflection & coupling losses at fibre ends without AR-coating and some absorption bands of atmospheric moisture, etc.)

Typical specification of CIR and PIR fibres

 

PIR Fibre

CIR Fibre

Spectral Range

3-18 mm

550-3300 cm-1

1.5-6.0 mm

1650-6650 cm-1

Fibre Material

AgCl:AgBr

As2S3 / As-S

Core / Cladding

400 / 500 mm

630 / 700 mm

900 / 1000 mm

180 / 275 mm

340 / 400 mm

500 / 550 mm

Refractive Index

ncore= 2.15

ncore = 2.4

Laser Damage Threshold

>12 kW/cm2

low power only

Effective NA

0.25

0.28

Optical Losses

Min. 0.2 - 0.3 dB/m

at 10-12 µm

Min. 0.2 dB/m

at 2-4 µm

Temperature

4 - 420 °K

270 - 370 °K

Terminations

SMA Ceramic

Titanium

High Power Titanium

FC Titanium in White Brass

 

SMA White Brass

 

FC White Brass

Maximum Length

<40m (PIR 400/500)

<30m (PIR 630/700)

<20m (PIR 900/1000)

<100m

Comparison of PIR and CIR Fibre Transmission Spectra for 1,5m length

Chalcogenide Infrared (CIR)

Chalcogenide infrared (CIR) glasses are the best As2S3-based material for fibre optics in the range of 1.5-6µm. CIR fibre is drawn in a core/clad structure with double polymer coating and is characterised by low optical loss and high flexibility.

Polycrystalline Infrared (PIR)

Transparent across a broad spectral region of 3-18mm polycrystalline infrared (PIR) fibre optic cables are non-toxic, extremely flexible and capable of operating over a wide temperature range of 4K up to 420K.

High Power Polycrystalline Infrared (HP-PIR)

For CO2 laser power delivery of <30W. Transparent across a broad spectral region of 3-18mm polycrystalline infrared (PIR) fibre optic cables are non-toxic, extremely flexible and capable of operating over a wide temperature range of 4K up to 420K.