High power ultra-stable mid-IR frequency combs
| Responsable du projet | Thomas Südmeyer |
| Collaborateur | Maxim Gaponenko |
| Résumé |
In the last decade, optical frequency combs from femtosecond lasers
have revolutionized numerous research areas in optical metrology,
spectroscopy, and time/frequency research. By providing a direct
and phase-coherent link between microwave and optical frequencies,
they enabled measurements of optical frequencies with extreme
precision. They led to the development of novel optical atomic
clocks with unprecedented frequency stability, and also triggered
impressive progresses in broadband high-resolution spectroscopy. In
a typical commercial frequency comb system, an ultrafast laser
operating at 800-nm, 1-µm, or 1.5-µm is launched into a
highly nonlinear fiber and generates an octave-spanning
supercontinuum spectrum. Due to the pump wavelength, the
supercontinuum is usually limited to the visible and near-infrared
spectral region. The development of sources providing stable
mid-infrared frequency combs in the 2-10 µm spectral region
is one of the major current research trends in optics and
photonics. Such sources give access to a spectral region in which
many relevant molecules have characteristic absorption lines, the
so-called “fingerprint region”. In this region, the detection
sensitivity can be strongly improved, which allows for faster
monitoring and higher precision in gas sensing. Moreover, the Earth
atmosphere has a transmission window in the 3-5 µm spectral
region where the dominant atmospheric absorbers like CO2 and water
vapor absorb poorly, which enables remote detection of environment-
or security-relevant substances like toxics or explosives. The
wavelength limitation is caused by a lack of suitable ultrafast
gain materials operating at long wavelengths. Commonly used gain
materials for ultrafast frequency combs are Ti:sapphire (800 nm),
Yb-doped gain materials (1 µm), Er-doped gain materials (1.5
µm), and recently Tm-doped gain materials (2 µm).
Optical parametric oscillators (OPOs) are an excellent method for
overcoming the wavelength limitations and generating radiation in
the mid-IR spectral region. In this SNF project, we want to
contribute to the development of powerful ultra-stable mid-IR
frequency combs. Ultrafast thin disk lasers (TDLs) have been
generating the highest power levels from any ultrafast oscillator
technology for many years. The combination of their high average
power and short pulse duration makes them very attractive for
pumping nonlinear parametric systems. In a first step, we want to
investigate low noise CEO-stabilized TDLs and increase their output
power levels. In a second step, we will use these sources to pump
mid-IR OPOs, and evaluate and optimize their frequency
stability. |
| Mots-clés |
Mid-infrared, Molecular fingerprinting, Ultrafast lasers, Optical parametric oscillator, Noise and stabilization, Optical frequency comb, Thin disk lasers |
| Type de projet | Recherche fondamentale |
| Domaine de recherche | Autres secteurs de la physique |
| Source de financement | FNS - Encouragement de projets (Div. I-III) |
| Etat | Terminé |
| Début de projet | 1-4-2015 |
| Fin du projet | 31-3-2017 |
| Budget alloué | 381'149.00 |
| Contact | Thomas Südmeyer |