Herr T., Brasch V., Jost J. D., Wang C. Y., Kondratiev N. M., Gorodetsky M. L., Kippenberg T. J. (2014), Temporal solitons in optical microresonators, in NATURE PHOTONICS
, 8(2), 145-152.
Wang Christine, Herr Tobias, Del'Haye Pascal, Schliesser Albert, Hofer Johannes, Holzwarth Ronald, Hänsch Theodor, Picqué Nathalie, Kippenberg Tobias (2013), Mid-Infrared Optical Frequency Combs based on Crystalline Microresonators, in Nature Communications
, 4, 1345-0.
Riemensberger Johann, Hartinger Klaus, Herr Tobias, Brasch Victor, Holzwarth Ronald, Kippenberg Tobias (2012), Dispersion engineering of thick high-Q silicon nitride ring-resonators via atomic layer depositionDeposition, in Optics Express
, 20(25), 27661-27669.
Fescenko Ilya, Alnis Janis, Schliesser Albert, Wang Christine, Kippenberg Tobias, Hänsch Theodor (2012), Dual-mode temperature compensation technique for laser stabilization to a crystalline whispering gallery mode resonator, in Optics Express
, 20(17), 19185-19193.
A. Schliesser, N. Picqué, T. W. Hänsch (2012), Mid-infrared frequency combs, in Nature Photonics
, 6, 440-449.
T. Herr, K. Hartinger, J. Riemensberger, C.Y. Wang, E. Gavartin, R. Holzwarth, M. Gorodetsky, T. J. Kippenberg (2012), Universal formation dynamics and noise of Kerr-frequency combs in microresonators, in Nature Photonics
, 6, 480-487.
Kippenberg T. J., Holzwarth R., Diddams S. A. (2011), Microresonator-Based Optical Frequency Combs, in SCIENCE
, 332(6029), 555-559.
Del'Haye P., Herr T., Gavartin E., Gorodetsky M. L., Holzwarth R., Kippenberg T. J. (2011), Octave Spanning Tunable Frequency Comb from a Microresonator, in PHYSICAL REVIEW LETTERS
, 107(6), 063901.
Optical frequency combs are a revolutionary tool for Metrology and allow unprecedented accuracy for determining optical frequencies. For their discovery its inventors Haensch and Hall have received the 2005 Nobel Prize in Physics. Frequency combs provide the optical clockwork for optical atomic clocks based on long lived atomic transitions, which will eventually replace Cs standard. Optical frequency combs have moreover proved powerful research tools enabling advances ranging from broadband gas sensing, Fourier transform spectroscopy to calibration of astrophysical spectrometers. Frequency combs have over the past decade been generated relying exclusively on mode locked lasers. In 2007, the applicant (TJ Kippenberg) demonstrated with his research group (while working at the MPI of Quantum Optics) a novel frequency comb generator based on the use of nonlinear parametric wave mixing in microresonators. This comb generator offers unprecedented form factor and moreover allows attaining a full octave without the need for any external broadening. In addition, due to the very small microresonators optical path length, repetition rates in the range exceeding 10 GHz have become possible with this new technology. These repetition rate are unavailable in conventional mode locked laser approaches, since the required cavity pathlength only equates to <4 mm. While early work of the PI using microresonators has made significant advances, culminating in fully phase stabilized and octave spanning (1000-2000 nm) combs from a single CW laser, new wavelength ranges have so far never been explored. This is precisely at the core of the research program described here.This research plan will extend this promising microresonator comb technology into new wavelength ranges: Notably, we will seek to enter the Intermediate and Mid-IR (>2000 nm) and visible (<700 nm) range with optical microresonators made from crystals and silica respectively. Both these frequency ranges could immensely profit from the availability of combs with high repetition rates, in particular since presently GHz mode spacing combs do not exist in the visible nor mid-Infrared portion of the spectrum. Pertaining to the broader context of the research, it is aimed at fully exploiting monolithic comb generators and allow this technology to mature and access new wavelength ranges. The benefits of this research could be far reaching. Not only that this type of comb generator is ideally suited for space applications - due to the compact form factor - , but moreover it holds promise in a variety of disciplines outside of Metrology. A particulary promising application in this context for visible combs is the calibration of astrophysical spectrometers for the search of exo-planets. Pioneering work from Geneva has used Thorium lambs as calibration tools, but with the emergence of frequency combs as sources of calibration, the need for visible combs with large mode spacing has become of major interest in astronomy in the race to search for the first-earth like planet. New calibration tools are and will be indispensible assets in this context and a frequency comb with large mode spacing in the visible has been proposed as an ideal tool. Moreover, combs in the mid and intermediate infrared are of benefit to chemist studying fundamental absorption lines in the molecular fingerprinting region, which to date is difficult to access. Quantum cascade laser sources exist, but presently lack the bandwidth phase stabilization.