Dual-comb spectroscopy is a powerful spectroscopic tool with ultrahigh-resolution,high-sensitivity properties,which opens up opportunities for the parallel detection of multi-species molecules.However,in its conventio...Dual-comb spectroscopy is a powerful spectroscopic tool with ultrahigh-resolution,high-sensitivity properties,which opens up opportunities for the parallel detection of multi-species molecules.However,in its conventional form,highly stable laser combs with sophisticated control systems are required to perform dual-comb spectroscopy.Here,a passive mutually coherent dual-comb spectroscopy system via an opticaloptical modulation method is addressed,where all fast phase-locking electronics are retired.Without post computer-based phase-correction,a high degree of mutual coherence between the two combs with a relative comb-tooth linewidth of 10 mHz is achieved,corresponding to a coherent time of 100 s.To demonstrate the performance and versatility of the system,the dual comb spectrometer is applied to record the mode-resolved single molecular spectra as well as parallel detected spectra of mixed gases including CO_(2),CO and C_(2)H_(2) that well agree with the established spectral parameters.Our technique exhibits flexible wavelength tuning capability in the near-infrared region and can be potentially extended to the midinfrared region for more applications.展开更多
Using the optical-optical double resonance （OODR） technique, we have studied the collisional broadening of some 21△g←B1πu lines in Na2 molecules. A single line Ar＋ laser is used to pump the sodium dimers from t...Using the optical-optical double resonance （OODR） technique, we have studied the collisional broadening of some 21△g←B1πu lines in Na2 molecules. A single line Ar＋ laser is used to pump the sodium dimers from thermally populated ground state X^1∑^＋g level to the intermediate B1πu state. Then, a single-mode diode laser is used to probe the doubly excited 21△g state. The broadening rate coefficient is determined from the slope of the total linewidth versus Ne density curve. We obtain the average value kbr = （1.1 ± 0.5）×10^-8 cm^3 8^-1. The collisional excitation transfer between rotational levels of the B1πu state （i.e.,B1πu（2,83/84） ←B1Ⅱu （2,82）） is also investigated. The rates can be determined from the relative intensities of the main peak and satellite lines, combined with a rate equation model. The rates of 1.25 × 106 and 1.07 × 106 s^-1 are obtained, respectively.展开更多
基金National Key R&D Program of China(2017YFF0206000,2018YFA0306301)National Natural Science Foundation of China(11904105,11874153,11804096).
文摘Dual-comb spectroscopy is a powerful spectroscopic tool with ultrahigh-resolution,high-sensitivity properties,which opens up opportunities for the parallel detection of multi-species molecules.However,in its conventional form,highly stable laser combs with sophisticated control systems are required to perform dual-comb spectroscopy.Here,a passive mutually coherent dual-comb spectroscopy system via an opticaloptical modulation method is addressed,where all fast phase-locking electronics are retired.Without post computer-based phase-correction,a high degree of mutual coherence between the two combs with a relative comb-tooth linewidth of 10 mHz is achieved,corresponding to a coherent time of 100 s.To demonstrate the performance and versatility of the system,the dual comb spectrometer is applied to record the mode-resolved single molecular spectra as well as parallel detected spectra of mixed gases including CO_(2),CO and C_(2)H_(2) that well agree with the established spectral parameters.Our technique exhibits flexible wavelength tuning capability in the near-infrared region and can be potentially extended to the midinfrared region for more applications.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 10264004.
文摘Using the optical-optical double resonance （OODR） technique, we have studied the collisional broadening of some 21△g←B1πu lines in Na2 molecules. A single line Ar＋ laser is used to pump the sodium dimers from thermally populated ground state X^1∑^＋g level to the intermediate B1πu state. Then, a single-mode diode laser is used to probe the doubly excited 21△g state. The broadening rate coefficient is determined from the slope of the total linewidth versus Ne density curve. We obtain the average value kbr = （1.1 ± 0.5）×10^-8 cm^3 8^-1. The collisional excitation transfer between rotational levels of the B1πu state （i.e.,B1πu（2,83/84） ←B1Ⅱu （2,82）） is also investigated. The rates can be determined from the relative intensities of the main peak and satellite lines, combined with a rate equation model. The rates of 1.25 × 106 and 1.07 × 106 s^-1 are obtained, respectively.
