Fig. 2: MIR spectrum and spatial resolution of the imaging system.
From: High-speed scanless entire bandwidth mid-infrared chemical imaging
Upconverted MIR spectrum by a 100 µm and b 4.4 µm thick GaSe crystal. c Calculation results of the configuration of GaSe crystal-type. d Spectrally resolved cross-correlation between the MIR pulse and the chirped pulse. e Upconversion MIR spectra of CO2 gas before and after retrieval. Infrared transmittance spectrum of CO2 gas by a commercially available FT-IR. f Image of a copper mesh grid. g Intensity profile marked by the red dashed line in f. The spatial resolution is estimated as 15 μm and is defined by the edge response of 10–90% distance of the line profile. h MIR hyperspectral stability at an exposure time of 8 s. CP: chirped pulse, MIR: mid-infrared, SFG: sum frequency generation, o: ordinary ray, e: extraordinary ray, FID: free induction decay.
