EPFL's High Field ESR Spectrometer
Here are pictures of our 200 to 400 GHz Homodyne Spectrometer supplied to Prof Lazlo Forro and his research Group in EPFL, Lausanne, Switzerland![Full Spctrometer](/images/tki/ESR/EPFL/EPFL_full_A.jpg)
Here is the Quasi-optical table, showing the source - Supplied by VDI as well as the Quasi-Optical Bridge and the InSb mixer, supplied in its cryostat.
![](/images/tki/ESR/EPFL/EPFL_feed_A.jpg)
This is the electrically-large corrugated feed horn, which allows the use of Zero Gain optics throughout the spectrometer, with the source feed horn being imaged directly onto the HE11 corrugated probe
![](/images/tki/ESR/EPFL/EPFL_Probe_feed_optics.jpg)
Here are the downward looking feed optics, which inject and recover the ESR probe beam into the HE11 probe into the cryostat.
![](/images/tki/ESR/EPFL/EPFL_Removing_probe.jpg)
Here are some results, looking at a small amount of NMP-TCNQ, and a kappa-(BEDT-TTF)2 Cu (NCS)2 single crystal oriented with c//B.
At 200 GHz
![200 Ghz with LO](/images/tki/ESR/EPFL/EPFL_200_wb.jpg)
An similar measurements without LO power
![200 Ghz without LO](/images/tki/ESR/EPFL/EPFL_200_withoutb.jpg)
And at 300 GHz
![300 GHz](/images/tki/ESR/EPFL/EPFL_300_withoutb.jpg)
and finally at 400 GHz, illustrating the multi-frequency capability of the Spectrometer.
Of course, to get this spectral coverage, you need a seriously powerful Magnet - in this case a 17Telsa magnet from Oxford Instruments.
![At 400 GHz](/images/tki/ESR/EPFL/EPFL_400_withoutb.jpg)