Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

摘要

A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

主权项

1. A photon-sensitive infrared (IR) spectromicroscopy system, comprising:
a light source; a plurality of cold mirrors configured to direct light emitted from the light source along a beam path; a sample holder positioned in the beam path and having portions transparent in at least a spectral range of interest, so light in the spectral range of interest is not absorbed and not emitted by the portions; a spectral device configured to direct a selected wavelength of light, polarization of light, and/or plurality thereof onto a detector; a plurality of cold apertures and a plurality of shields positioned along the beam path, the cold apertures and shields being configured to prevent thermal emission originating from the sample holder from reaching the detector; a sub-K refrigerator configured to maintain a detector temperature below an upper operational temperature threshold less than about 1.0 K; and an enclosure configured to thermally insulate the light source, the plurality of mirrors, the spectral device and the sub-K refrigerator; and wherein the sample holder is characterized by a path length less than a radiation equilibration length of a medium through which light from the light source travels.