Mid-TECH – Development of tunable high-power MOPA systems for non-linear frequency conversion

The Mid-TECH ITN project investigates a new and promising technique of detection in the mid-IR spectrum, the so called up-conversion process. In this process, an IR signal is mixed with light from a pump laser source inside a non-linear crystal. When the light is mixed in such a crystal, and under phase matching conditions, the sum frequency generation process occurs between the two beams, resulting in a frequency “up-conversion” of the detected signal. This corresponds to a wavelength shift from IR to the visible region, where the detection process is much more efficient compared to the detection in the IR spectrum.

The objective of this project is to develop a highly tunable, high-power, diode-based MOPA system for the up-conversion process. By tuning the wavelength of the pump source, different parts of the IR spectrum are up-converted, i.e. sweeping the different absorption peaks of the detected signal/sample. Thus, up-converting a broad part of the IR spectrum into the visible region enables hyper spectral imaging and absorption/DIAL spectroscopy in the IR-region.

This technique provides new and exciting possibilities, since most complex molecules, such as those found in food, tissue or catalytic compounds all have vibrational spectra in the mid-IR. In particular, this technique will be implemented in two main fields: the detection of gas molecules in low concentrations for applications like; combustion analysis, “leak-tests” or remote sensing of greenhouse gases. Besides of these industrial applications, this technique will also be applied for the detection of molecular compositions in breast tissue. This will provide a new technique for early prediction of cancer, where breast calcifications have been shown to exhibit clear differences in composition, found in healthy and cancerous tissue.

Mid-TECH (duration 01.01.2015 – 31.12.2018)

Funding: European Commission grant number 642661