Periodic Reporting for period 1 - PocketLight (Compact all-fibre nonlinear resonators as technological platform for a new generation of miniaturised light sources.)
Período documentado: 2020-09-01 hasta 2022-08-31
The project addressed the issue of opening the way towards the implementation of a new generation of efficient and miniaturized light sources. The social impact of this project is mainly related to the reduction of sizes, of maintenance costs and consequently energy consumption for the implementation and use of light sources in the technological area of Microwaves Photonics, but not necessarily limited to that. The overall objectives of the project are the theoretical study and the experimental realization of a proof of principle of a light source based on compact all-fiber nonlinear resonators.
The work performed during the whole period of the project has been first a work of acquisition of skills related to the theoretical study of the dynamics of nonlinear fiber cavities. After this training, various numerical simulations have been performed to engineer a fiber nonlinear cavity capable to sustain temporal solitons characterized by specific features, and in particular by a short pulse duration, compared to what already present in literature. Experimental skills have been acquired related to the process of stabilization of fiber cavities and of soliton addressing in those cavities. Then it has been studied the possibility of experimentally implementing nonlinear fiber cavities in in-line configuration. Some technological issues have been addressed, specifically the realization of mirrors suitable for the implementation of those in-line cavities. A preliminary study has been performed with the scope of fabricating dielectric stacks on the facets of a specific type of optical fiber, to be used as reflectors for the implementation of the compact all-fiber resonator. Alternative solutions have been also found to circumvent potential practical difficulties in the realization of those dielectric stacks, such as for example the adoption of fiber Bragg gratings as input and output couplers/reflectors for those cavities. A setup for thermal poling of optical fibers and a setup for UV erasure of second order nonlinearity have been also implemented with the scope of fabrication of new samples of periodically poled fibers. The most important scientific results of the project are summarized in a publication in Nature Photonics, where it has been reported the first all-fiber optical parametric oscillator (OPO) for the generation of parametrically driven Kerr cavity solitons. In this paper the periodically poled fiber, which represents the base of the technological platform proposed in my project, has been adopted in conjunction with an active fiber (Erbium doped fiber) to generate solitary waves suitable for the application such as random bit generation and Ising machines. The results of this work have been disseminated also in international conferences and workshops. The relevance of this work stands in the fact that all the results obtained will be re-used for a future implementation of a compact all-fiber resonator, which will need to be modified to include optical gain.
The work realized during this project has already pushed the performances of the fiber nonlinear resonators beyond the state of the art, in particular in the direction of the reduction of the pulse duration of the generated laser pulses associated to cavity solitons, and consequently the increase of the range of frequencies in the spectral domain which the potential light source based on nonlinear cavity frequency combs could possess. The work published in Nature Photonics, instead, gives the first experimental proof that the technological platform proposed and based on periodically poled optical fibers is suitable for the scope of realizing an all-fiber nonlinear compact resonator for the realization of efficient and miniaturized light sources in the Microwave domain. The technological and consequently socio-economic impact of the project might be significant, considering that the activity will be pursued in the next years.