Scanless quantum Fourier-transform mid-infrared spectroscopy for solids and surface analysis

In this approach, spectrally far-separated correlated photon pairs are used for detection and probing, respectively. Hence, the probing wavelength domain (mid-IR) is substantially different from the detection spectral range (near-IR), which enables shot-noise-limited and cost-effective sensing schemes attractive for applied metrology.

In this paper, we implement and employ a custom-built scanless quantum Fourier-transform mid-IR (sQFTIR) microspectrometer for chemical characterization and analysis of solids and interfaces. The sQFTIR system employs spectral-domain acquisition, without the need to scan the optical delay. This results in enhanced sensitivity and short measurement times and therefore enables rapid spectral acquisitions in 100~ms spanning a spectral band from 3000 cm$^{-1}$ - 2400 cm$^{-1}$.