Edinburgh CO2 Gas Laser + Bruker Vertex 70 FTIR

The FIRL100 CO2 gas laser has been moved to Fronczak 224 for use with the Bruker FTIR.


Both tables supporting the FIRL100 CO2 laser were moved into Fronczak 224 (back of room).

To optimize work space in Fronczak 224, a scaled Blender file was created.


Scaled Blender rendering of Fronczak 224.

Blender Resource: Fronczak_224_E.blend

The lab was rearranged accordingly.


FTIR table turned to accommodate the FIRL100 tables with adequate work space all-around.


  • August 9, 2022. Mechanical resources for the FIRL100 are coming together (mechanical pumps, chilled water, etc.)
  • November 1, 2022 | The system is fully installed. Initial power-up yielded $P_{{\rm CO}_2} > 30$ W and $P_{{\rm FIR}}=51$ mW
  • January 10, 2023 | $P_{{\rm FIR}}=74$ mW using methanol at $\lambda = 118.8 \mu$m as a maximum power. It's stable around 60 mW for at least an hour. Notably, the gas mixture used has slightly lower CO2 concentration than recommended, so the maximum achievable power is lower than previous results.


Side View of FIRL 100 with supporting equipment. January 2023.


About the FIRL100

The FIRL100 is an integrated carbon dioxide (CO2) and far infrared (FIR) laser system designed to give high output power in the 9-11 $\mu$m wavelength region with good frequency and amplitude stability coupled with powerful FIR emission in the 40 $\mu$m to 1.22 mm wavelength range. Access to either form of radiation is easily achieved by moving the mirror control at one end of the laser to either of two positions.

The CO2 section of the FIRL100 may be operated in a flowing gas mode to obtain highest output powers. The laser gain section is a single arm water-cooled discharge tube sealed with Brewster angled ZnSe windows in air-cooled mounts. The optical resonator is supported on an invar frame to minimize cavity length changes induced by thermal expansion. The invar frame is itself vibration decoupled from the base plate by Rose bearings. This construction ensures optimum passive mechanical and thermal stability.

The CO2 resonator consists of a partially reflecting ZnSe output coupling mirror and a blazed diffraction grating. The output coupler is mounted on a piezo-electric transducer that allows fine control of the cavity length, hence, the output frequency.

The FIR part of the FIRL100 is also mounted on the common invar rod frame. It comprises a ZnSe input Brewster window that forms a vacuum seal at one end of the laser, a flat chromium gold coated stainless steel input mirror at one end of the laser, and a specially optimized dichroic output coupler from which the FIR power is extracted. A water-cooled oversized Pyrex waveguide of 36 mm inside diameter is used.

Operating and System Manuals are available to instrument users.

About the Bruker Vertex 70 FTIR

The Bruker Vertex 70 Fourier-transform infrared (FTIR) spectrometer allows measurement of infrared absorption for analytical and research purposes. The FTIR allows fast collection of IR spectra of a variety of sample types including solid bulk, liquid, or thin films.