FIR System (7.5 THz – 0.25 THz)

  • Far-Infrared (FIR) / Terahertz laser emission: 40 μm – 1.2 mm (7.5 THz – 0.25 THz)
  • FIRL-100 is a FIR laser pumped by a CO2 laser in one housing
  • Fusion reactor plasma temperature measurement
  • Homeland security and scanning
  • Scattering density measurements
  • Radar modelling
FIR System (7.5 THz – 0.25 THz)

The FIRL-100 has both the CO2 pump laser (PL5 or PL6) and the FIR laser (295-FIR or 395-FIR) housed in an integrated structure combining a highly efficient optically pumped FIR system into a single compact unit. The lasers and coupling optics are mounted within a 5 bar invar rod frame for excellent thermal and mechanical stability.


The CO2 section provides 80 lines between 9.1 μm and 10.9 μm and features a flowing gas single discharge tube giving more than 50 W on the strongest lines. Mode performance (M2 <1.25) is assured by internal profiling of the tube and the use of high quality optics. The resonator design is based on the proven PL5 laser with diffraction grating, two ZnSe Brewster windows and piezo ceramic mounted ZnSe output coupler.

The CO2 laser output is coupled into the FIR laser via two steering mirrors and a ZnSe focussing lens. Access to the CO2 radiation beam diagnostics for Infrared experiments is available via a precision, two position sliding mirror mechanism.

FIRL-100 Output Specification   
Wavelength (µm)FIR MoleculeCO2 Pump LineTypical Power
96.5CH3OH9R1060 mW
118.8CH3OH9P36150 mW
184.3CH2F29R32150 mW
432.6CH3OH9R2030 mW
513CH3OH9R2810 mW

Laser Stabilisers

For applications demanding excellent medium and long tern stability, an active stabiliser may be required. This will compensate for laser output fluctuations caused by changes in ambient conditions and lock the variation in laser frequency or power to a value close to the passive jitter. Edinburgh Instruments has designed a family of active stabilisation techniques appropriate to the type of laser and operating conditions. Stabilisation of laser output is possible for up to 60 minutes.

Laser Pumping and Refilling Systems

All flowing gas laser systems are supplied with the necessary valves, gauges and vacuum couplings for simple connection to the system vacuum pump. A range of turbo molecular and dry pumps are available as upgrades. Please contact us for more information.

Gas Mixing Stations

These are designed to allow mixing and metering of up to 3 component gases from independent gas cylinders. Comprising of 3 inlet ports with individual flow meters or needle valves for gas mixing or gas flow operation.