Mid-IR hyperspectral imaging with undetected photons
M. Placke1, C. Lindner2, F. Mann1, I. Kviatkovsky1, H.M. Chrzanowski1, H. Bartolomaeus3, F. Kühnemann2,4, and S. Ramelow1,5
Published in:
Optica, vol. 13, no. 2, pp. 328-335, doi:10.1364/OPTICA.573220 (2026).
Abstract:
We present a digital holography method for measuring the dispersive properties of semiconductor laser waveguides. The approach is based on low-coherence off-axis holography and enables the determination of wavelength-dependent group delay and group index with high accuracy. In a wavelength range of 830–870 nm, the optical path difference is evaluated through the degree of coherence between object and reference waves. Compared to existing interferometric techniques, the method allows flexible measurements outside of integrated devices and avoids aliasing artifacts in spectroscopic approaches. Experimental results obtained with InGaAsP-based semiconductor lasers show good agreement with theoretical models and demonstrate the suitability of this technique for dispersion characterization. In addition, the setup can be extended to measure other key laser parameters, such as carrier-induced refractive index changes, offering a versatile tool for semiconductor laser analysis.
1 Institute for Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
2 Fraunhofer Institute for Physical Measurement Techniques IPM, Georges-Köhler-Allee 301, 79110 Freiburg, Germany
3 Institute of Experimental Biomedicine, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany
4 Institute of Physics, Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
5 Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
Related Topics:
Fourier transform infrared spectroscopy, Frequency combs, Imaging systems, Imaging techniques, Light sources, Quantum imaging
© 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
Full version in pdf-format.