Terahertz Thermometry: Combining Hyperspectral Imaging and Temperature Mapping at Terahertz Frequencies

Abstract

The accurate and non‐invasive determination of multiple physical parameters, with well‐defined spatial resolution, is crucial for applications in manufacturing, chemistry, medicine and biology. Specifically, the ability to simultaneously measure both temperature and spectral signatures is still experimentally unavailable. To this end, we propose a mapping technique for biological systems, which exploits a linear correlation between terahertz wave reflectivity and temperature, and allows to spatially and spectrally resolve thermal distributions. This method is applied to a model biological system in two relevant cases where in one example, nanoplasmonic‐induced photothermal effects are imaged gaining new insights into collective heating phenomena. In the second example, we demonstrate a joint thermal‐hyperspectral imaging approach to chemically map the presence of a model drug formulation and simultaneously investigate its thermal stability in our biological system. This concept can be easily extended and widely applied to all materials that demonstrate a measurable change in their dielectric properties.

Highly Efficient Copper Sulfide‐Based Near‐Infrared Photothermal Agents: Exploring the Limits of Macroscopic Heat Conversion

“…These simulations were performed by solving the heat diffusion equation in the simplified system, with the whole nanoparticle dispersion being a homogeneous source of heat (mimicking the stirring conditions of the experiment), and with its magnitude calculated via the Beer–Lambert law. This type of photoheating is highly collective and suitable for the generation of heat over relatively large volumes, making it of interest for many biorelated applications . The above‐reported results illustrate how, even in a simulated system that does not account for energy dissipation mechanisms other than plasmonic absorption converted into heat, the computation of HCE depends strongly on the solvent absorption profile (Figure E).…”

Ultrafast Frequency Shift of Electromagnetically Induced Transparency in Terahertz Metaphotonic Devices

“…Terahertz (THz) wave ranging from 0.1 to 10 THz is on the cutting edge of new technologies, since it shows great prospects for applications in chemical analysis, nondestructive medicine biology, high‐speed communication, and security imaging . These practical THz applications naturally stimulate further research on the efficient THz emission, modulation and detection.…”

Time-domain terahertz compressive imaging

“…Moreover, the capability of performing time-domain coherent detection (amplitude and phase information) of the THz electric-field waveform enables full material characterization, including the retrieval of the complex refractive index [3] and the chemical recognition of substances (e.g., gases [4], organic materials [5], bio-molecules [6]) that feature rotational/vibrational transitions, or collective excitations (e.g., phonons and magnons) in the THz range. This make THz imaging a promising technology for a multitude of applications including security [7], quality and safety control in industry [8,9], biomedical applications [10,11] and also art conservation [12,13]. The main hurdle that still hampers wide spread application of THz imaging technology is the long acquisition time [14].…”