Infrared chemical imaging through non-degenerate two-photon absorption in silicon-based cameras.
David KnezAdam M HanninenRichard C PrinceEric O PotmaDmitry A FishmanPublished in: Light, science & applications (2020)
Chemical imaging based on mid-infrared (MIR) spectroscopic contrast is an important technique with a myriad of applications, including biomedical imaging and environmental monitoring. Current MIR cameras, however, lack performance and are much less affordable than mature Si-based devices, which operate in the visible and near-infrared regions. Here, we demonstrate fast MIR chemical imaging through non-degenerate two-photon absorption (NTA) in a standard Si-based charge-coupled device (CCD). We show that wide-field MIR images can be obtained at 100 ms exposure times using picosecond pulse energies of only a few femtojoules per pixel through NTA directly on the CCD chip. Because this on-chip approach does not rely on phase matching, it is alignment-free and does not necessitate complex postprocessing of the images. We emphasize the utility of this technique through chemically selective MIR imaging of polymers and biological samples, including MIR videos of moving targets, physical processes and live nematodes.
Keyphrases
- cell proliferation
- long non coding rna
- high resolution
- long noncoding rna
- physical activity
- magnetic resonance imaging
- multiple sclerosis
- high throughput
- mass spectrometry
- mental health
- circulating tumor cells
- convolutional neural network
- risk assessment
- room temperature
- computed tomography
- climate change
- molecular dynamics simulations
- life cycle