Temporal dissipative solitons in continuous-wave (CW) laser-driven Kerr-nonlinear microresonators have led to the generation of highly-coherent optical frequency combs and ultra-short optical pulses with repetition rates in excess of 10 GHz. Applications of such sources include optical telecommunication, microwave signal generation and optical spectroscopy. Here, a novel nonlinear optical Fabry-Perot microresonator is synchronously driven by picosecond laser pulses (instead of a CW laser) resulting in the formation of temporal dissipative solitons at 10 GHz repetition rate. As opposed to the conventional CW-driven case, single or multiple solitons form deterministically ‘on-top’ of the resonantly enhanced driving pulses, which significantly increases conversion efficiency. The solitons lock to the driving pulse, which enables stable operation and coherent actuation of the solitons’ repetition rate and carrier-envelope offset frequency. The Fabry-Perot microresonator with 10 GHz free-spectral range is based on a short length of standard optical fiber whose end-facets are coated with dielectric Bragg mirrors. Mounted inside a fiber-optical ferrule, the resonator can be interfaced directly with other fiber optical components. While being equivalent to whispering-gallery mode and ring-type resonators regarding nonlinear optical phenomena, the Fabry-Perot microresonator allows for straightforward design of group velocity dispersion, coupling ratio and nonlinearity via choice of fiber and dielectric mirrors. In summary, the presented results links the fields of CW driven microresonators, synchronously driven optical parametric oscillators as well as pulsebased non-resonant supercontinuum generation. Amongst others, they open new perspectives for microresonator-based frequency combs generation and for nonlinear photonics driven by temporally and spectrally structured light.
Observatoire de Neuchâtel (ON) is developing a compact optically-pumped cesium beam frequency standard in the frame of an ESA-ARTES 5 project. The simplest optical scheme, which is based on a single optical frequency for both preparation and detection processes of atoms, has been chosen to fulfill reliability constraints of space applications. With our laboratory demonstrator operated at 852 nm (D2 line), we have measured a frequency stability of σy=2.74x10-12 τ -1/2, which is compliant with the Galileo requirement. The atomic resonator is fully compliant to be operated with a single diode laser at 894 nm (D1 line). Sensitivity measurements of the clock signal to the microwave power and to the optical pumping power are also presented. Present performance limitations are discussed and further improvements are proposed in order to reach our ultimate frequency stability goal of σy=1x10-12 τ -1/2. The clock driving software is also briefly described.