Optical experiments at dilution refrigerator temperatures

To perform time- and frequency resolved experiments at milliKelvin temperatures, we coupled a high-resolution FTIR spectrometer to an optically-enabled dilution refrigerator. With all off-axis parabolic design we have achromatic, low aberration light transmission.

CAD drawiing of coupling setup
Optical spot at the fridge sample plane,
identical to the source aperture.