Junior Faculty Spotlight: Josh Caldwell
Infrared spectroscopic and imaging techniques are widely implemented for non-contact measurements of temperatures, chemical identification and medical diagnostics, astronomical studies, and due to atmospheric windows in the 3-5 and 8-12 µm spectral ranges for thermal radiative cooling, free-space communications. In the visible spectral range there is a broad range of materials that offer ideal performance and due to the short wavelengths of light compact optical components, in the infrared, the materials of choice tend to have significant issues such as low transmission, high expense, high reactivity in ambient conditions and/or being very brittle. Furthermore, the long free-space wavelengths mean optical components must be significantly larger. Polaritons, which are quasi-particles of oscillating charges with light (photons), provide the means to circumvent the limitations of these long-wavelengths in the IR and focus the light to nanoscale dimensions. However, identifying the appropriate materials and device concepts that can suitably overcome these limitations is at the heart of my research.