Quantum sensing of light with sub-wavelength resolution
Optical systems capable of generating fields with sub-wavelength spatial dimensions have become standard in science and engineering research and industry. Pertinent examples include atom- and ion-based quantum computers, optical lithography setups, etc. Such fields have intensity and polarization variations at the sub-wavelength scale, and so far, no tools exist for characterizing these.
In this work, we used a trapped ion, with a spatial wavepacket much smaller than the wavelength of light, to perform the highest resolution intensity and polarization measurement to date. This technique opens up a new avenue to characterize light sources at the subwavelength scale and will have a direct impact on the characterization of optical setups in lithography and atom- and ion-based quantum computers.
I will present the theory and experiment that led to these measurements, and we will also discuss how deep neural networks can be used to drastically speed up optical field reconstruction, making this technique deployable to characterize large optical setups.