
Ludwig-Maximilians-Universität München, Max Planck Institute of Quantum Optics
LMU | Faculty of Physics
Schellingstr. 4
80799 München
Tel. +49 89 2180 3212
t.w.haensch[at]physik.uni-muenchen.de
Group WebpageDescription
Research focus: quantum many-body physics, quantum optics, laser physics

Precission laser spectroscopy

Laser frequency combs
Laser frequency combs are becoming compelling instruments for broadband molecular spectroscopy by dramatically improving the resolution and recording speed of Fourier spectrometers and by creating new opportunities for highly-multiplexed nonlinear spectroscopy and imaging. Advanced laser and photonic technologies, involving optical parametric oscillators, silicon photonics or high-quality factor micro-resonators, extend the spectral territory of frequency comb generators to the mid-infrared region, range of the fingerprints of molecules. Real-time coherent Raman comb-based hyperspectral imaging opens intriguing perspectives for microscopy of biological samples. Two-photon spectroscopy with two laser combs holds promise for Doppler-free spectroscopy of molecules.
Optical microcavities
Optical micro-cavities are powerful photonic devices with applications ranging from cavity quantum electro-dynamics with solid-state emitters to novel schemes for cavity-enhanced microscopy and spectroscopy. With laser-machined optical fibers, open-access cavities of very high finesse and small mode waist are harnessed to realize an efficient optical interface for color centers in nano-systems. This should lead to efficient single-photon sources and may provide a route towards the strong coupling regime in a cryogenic environment. Other experiments explore the potential of such micro-cavities for ultrasensitive spectroscopy of individual nano-scale objects, such as carbon nanotubes and gold nanoparticles.