Université de Neuchâtel

Compact ultrafast frequency combs

Hakobyan, Sargis ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Optical frequency combs provide a direct and phase-coherent link between the optical spectral region of the electromagnetic spectrum (i.e., hundreds of THz frequencies) and the radio-frequency domain (MHz-GHz frequencies). As a result, they constitute a unique and powerful tool for various applications such as broadband high-resolution molecular spectroscopy, optical metrology, astrophysics,...

Université de Neuchâtel

Novel ultrafast high-power thin-disk laser oscillators and applications for metrology and XUV generation

Paradis, Clément ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Ultrafast lasers have revolutionized research in fundamental physics, chemistry and biology as well as industrial applications. A great number of experiments benefit from the development of Yb-based high-power femtosecond laser sources. These systems typically include a low-power mode-locked oscillator followed by amplifier stages relying on fiber, slab or thin-disk technologies. In many cases,...

Université de Neuchâtel

Novel laser sources for metrology and spectroscopy

Gürel, Kutan ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

Lasers have revolutionized the photonics field as a coherent intense light source, capable of performing many tasks. They are widely used in industrial and medical applications, as well as for scientific research. Two important areas of applications are frequency metrology and spectroscopy. Quantum cascade lasers (QCL) cover a wide spectral region in the mid-infrared where most molecules exhibit...

Université de Neuchâtel

Évaluation métrologique de l'étalon primaire de fréquence FoCS-2 avec une incertitude de quelques 10-15

Jallageas, Antoine ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

This work focusses on the study and the metrological evaluation of the FoCS-2 primary frequency standard. This atomic clock, one of a kind, uses a continuous beam of cold cesium atoms. Following 20 years of development in the Observatory of Neuchâtel and the Time and Frequency Laboratory of the University of Neuchâtel, FoCS-2 is now located in the federal institute of metrology METAS in Bern....

Université de Neuchâtel

Analysis and improvement of the spectral properties in mid-infrared semiconductor quantum cascade lasers

Tombez, Lionel ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2014.

Quantum Cascade Lasers (QCLs) are semiconductor lasers based on intersubband transitions in semiconductor heterojunctions. Unlike conventional laser diodes, the emission wavelength of QCLs is not defined by the energy gap between the conduction and valance bands of the semiconductor material, but by the energy spacing between the discrete states of quantum wells, which enables the realization of...

Université de Neuchâtel

All-optical microwave generation using frequency combs

Dolgovskiy, Vladimir ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2012.

Optical frequency combs from modelocked femtosecond lasers provide a direct, phase-coherent link between the radio frequency and optical domains. This thesis describes the development and realization of an ultra-stable microwave oscillator based on optical-to-microwave frequency transfer using two different optical frequency comb technologies. An optical reference oscillator is realized...