Sustained mutual coherence between 2 combs over extended periods is a prerequisite for dual-comb spectroscopy(DCS),particularly in achieving high-resolution molecular spectroscopy and precise spectral measurements.How...Sustained mutual coherence between 2 combs over extended periods is a prerequisite for dual-comb spectroscopy(DCS),particularly in achieving high-resolution molecular spectroscopy and precise spectral measurements.However,achieving long coherence times remains a challenge for Yb-doped frequency combs.This work introduces an experimental approach for phase-stable DCS using Yb-doped frequency combs at 1.03μm with a novel feed-forward method,combatting the limitations of mutual coherence.Without relying on postprocessing or self-correction algorithms,we achieve a coherence time of 1,000 s-3 orders of magnitude longer than the current state of the art for DCS.This extended coherence enables time-domain averaging,resulting in a signal-to-noise ratio(SNR)of 2,045.We demonstrate high-resolution monitoring of weak overtone transitions in the P and R branches of C_(2)H_(2),achieving good agreement with simulated spectra based on HITRAN parameters.The phase-locked multiheterodyne system also enables phase spectrum measurements with a scatter down to 7 mrad.Furthermore,we successfully extend our technique to the visible spectral region using second harmonic generation,achieving high-resolution spectra of NO_(2)with excellent SNR.The method offers high-frequency accuracy and demonstrates the potential of Yb-doped systems for multiplexed metrology,effectively extending the capabilities of DCS as a powerful tool for multi-disciplinary applications.展开更多
A vibration feeder is a piece of equipment for rationing and conveying powder,particle and block materials.In order to test the regeneration performance of de-dusting medium for high-temperature coal gas,a set of de-d...A vibration feeder is a piece of equipment for rationing and conveying powder,particle and block materials.In order to test the regeneration performance of de-dusting medium for high-temperature coal gas,a set of de-dusting medium-feeding systems was designed quantitatively.The de-dusting medium-feeding system is used in the gasification process for cleaning coal gas.The system is mainly composed of a hopper unit,control unit and feeding unit.In order to optimize the feeding stability of the coal-gas dust-removal medium vibration feeding system,the setting and scope of the following design factors and operating factors are investigated.Specifically,it includes the influence of gate-valve-opening adjustment of the control unit on the feeding stability of a vibrating feeding system;the influence of the gap size of the dipleg of the control unit on the feeding sensitivity of the vibration system;the influence of the particle size of the de-dusting medium on the operating range of the vibrating feeding system;the influence of the digitization of the working-current indicator of electromagnetic vibrating feeders on measurement variation and the process variation of a vibration feeding system.This vibration feeding system can realize the function of precise and quantitative feeding of the de-dusting medium,which can meet the design requirements of subsequent experimental research.展开更多
基金supported by the HORIZON EUROPE European Research Council(947288)Austrian Science Fund(FWF)(Y1254)funding from the European Union(grant agreement 101076933 EUVORAM).
文摘Sustained mutual coherence between 2 combs over extended periods is a prerequisite for dual-comb spectroscopy(DCS),particularly in achieving high-resolution molecular spectroscopy and precise spectral measurements.However,achieving long coherence times remains a challenge for Yb-doped frequency combs.This work introduces an experimental approach for phase-stable DCS using Yb-doped frequency combs at 1.03μm with a novel feed-forward method,combatting the limitations of mutual coherence.Without relying on postprocessing or self-correction algorithms,we achieve a coherence time of 1,000 s-3 orders of magnitude longer than the current state of the art for DCS.This extended coherence enables time-domain averaging,resulting in a signal-to-noise ratio(SNR)of 2,045.We demonstrate high-resolution monitoring of weak overtone transitions in the P and R branches of C_(2)H_(2),achieving good agreement with simulated spectra based on HITRAN parameters.The phase-locked multiheterodyne system also enables phase spectrum measurements with a scatter down to 7 mrad.Furthermore,we successfully extend our technique to the visible spectral region using second harmonic generation,achieving high-resolution spectra of NO_(2)with excellent SNR.The method offers high-frequency accuracy and demonstrates the potential of Yb-doped systems for multiplexed metrology,effectively extending the capabilities of DCS as a powerful tool for multi-disciplinary applications.
文摘A vibration feeder is a piece of equipment for rationing and conveying powder,particle and block materials.In order to test the regeneration performance of de-dusting medium for high-temperature coal gas,a set of de-dusting medium-feeding systems was designed quantitatively.The de-dusting medium-feeding system is used in the gasification process for cleaning coal gas.The system is mainly composed of a hopper unit,control unit and feeding unit.In order to optimize the feeding stability of the coal-gas dust-removal medium vibration feeding system,the setting and scope of the following design factors and operating factors are investigated.Specifically,it includes the influence of gate-valve-opening adjustment of the control unit on the feeding stability of a vibrating feeding system;the influence of the gap size of the dipleg of the control unit on the feeding sensitivity of the vibration system;the influence of the particle size of the de-dusting medium on the operating range of the vibrating feeding system;the influence of the digitization of the working-current indicator of electromagnetic vibrating feeders on measurement variation and the process variation of a vibration feeding system.This vibration feeding system can realize the function of precise and quantitative feeding of the de-dusting medium,which can meet the design requirements of subsequent experimental research.
