Broadband Upconversion imaging
Broadband Upconversion imaging, where mid-infrared (IR) photons are converted to visible and near IR photons via a nonlinear crystal and detected on a high-performance room temperature Silicon detector, is an appealing method to address the limitations of thermal sensors which are expensive, often require cooling and suffer from both limited spectral response and limited spatial resolution as well as poor sensitivity.
However, phase matching severely limits the spectral bandwidth of this technique, therefore, requiring serial acquisitions in order to cover a large spectrum.
In our work, we have introduced a novel upconversion imaging scheme covering the mid-IR based on adiabatic frequency conversion.
We have presented a mid-IR multicolor imaging and demonstrated simultaneous imaging on a CMOS camera of radiation spanning a spectrum from 2 to 4 µm.
We have further shown spectrally resolved Spatio-temporal imaging, which allows spatially distinguishing the temporal evolution of spectral components.