Künstliche Anpassung der Eigenschaften nichtlinear optischer Effekte für die Verbesserung verteilter Fasersensoren
Optik, Quantenoptik und Physik der Atome, Moleküle und Plasmen
Zusammenfassung der Projektergebnisse
In conventional Brillouin sensors the sensing length, the acquisition time and the spatial resolution are restricted by the bandwidth of the gain resonance. Thus, the main objective of the proposal was to investigate methods to reduce the natural bandwidth of SBS and to incorporate them in Brillouin sensors in order to drastically improve the performance of these sensors. The subobjectives of the project were: Reduction of the SBS gain bandwidth by more than one order of magnitude. - Enhancement of the existing theory, simulation and experimental proofs for SBS bandwidth reduction and determination of the physical limits. - Increasing the length and spatial resolution and decreasing the acquisition time of Brillouin optical sensors by the incorporation of bandwidth reduction methods in proof-of-concept sensor setups. In the funded DFG project, the TU-BS group: has reduced the SBS gain bandwidth by around one order of magnitude and has applied this spectrum engineered gain for sensors, has enhanced the existing theory and determined the limits by the derivation of a coupled differential equation system for the gain with losses and has carried out simulations and experimental verifications, has found a unique way to achieve a higher SNR, to improve the measurand resolution and the sensing range and to circumvent non local effects (NLE). In proof-of-concept sensor setups this has been used for increasing the sensor length or spatial resolution or decreasing the acquisition time. Thus, all envisioned goals were achieved. Additionally, we have found: that spectrum engineering can be very beneficial for dynamic sensors. Thus, together with Moshe Turs group from the Tel Aviv University we have carried out first proof-of-concept experiments for spectrum engineered dynamic sensing and have submitted a research proposal to the Volkswagen foundation. That the noise in SBS based sensors is barely investigated. Thus by theory and first experiments, we have investigated the phase-to-intensity and stimulated Brillouin noise, we have developed several ideas for the noise reduction and have submitted a research proposal regarding the investigation of origin and mitigation of noise in SBS based sensors to the DFG. Besides for sensors, spectrum engineering can be very beneficial for other applications of SBS, like microwave and photonic filters. Thus we have proposed additional noise free, tunable rectangular filters based on SBS spectrum engineering. We have investigated filters based on SBS spectrum engineering and out-ofphase cancellation, and we have investigated methods to measure the dispersion of waveguides based on out-of-phase cancellation.
Projektbezogene Publikationen (Auswahl)
- "Effects of pump pulse extinction ratio in Brillouin optical time-domain analysis sensors," Opt. Express 25, 27896-27912 (2017)
H. Iribas, J. Mariñelarena, C. Feng, J. Urricelqui, T. Schneider, and A. Loayssa
(Siehe online unter https://doi.org/10.1364/OE.25.027896) - "The Influence of Dispersion on Stimulated Brillouin Scattering Based Microwave Photonic Notch Filters," J. Lightw. Technol. 36, 5145–5151 (2018)
C. Feng, S. Preussler, and T. Schneider
(Siehe online unter https://doi.org/10.1109/JLT.2018.2871037) - “Sharp tunable and additional noise-free optical filter based on Brillouin losses,” Photon. Res. 6, 132 – 137 (2018)
C. Feng, S. Preußler, and T. Schneider
(Siehe online unter https://doi.org/10.1364/PRJ.6.000132) - "The State-of-the-Art of Brillouin Distributed Fiber Sensing," in Brillouin Distributed and Fiber-Bragg-Grating-Based Fiber Sensing - Principle, Measurement and Applications (IntechOpen, 2019)
C. Feng, J. Emad Kadum, and T. Schneider
(Siehe online unter https://doi.org/10.5772/intechopen.84684) - “Gain spectrum engineering in distributed Brillouin fiber sensors,” J. Lightw. Technol. 37, 5231–5237 (2019)
C. Feng, X. Lu, S. Preussler, T. Schneider
(Siehe online unter https://doi.org/10.1109/JLT.2019.2930919) - “Measurement accuracy enhancement via radio frequency filtering in distributed Brillouin sensing,” Sensors 19, 2878 (2019)
C. Feng, J. Kadum, S. Preussler, T. Schneider
(Siehe online unter https://doi.org/10.3390/s19132878)
