We measure the absorption and dispersion in a Doppler-broadened A-type three level system by resonant stimulated Raman spectroscopy with homodyne detection. Through studying the dressed state energies of the system, i...We measure the absorption and dispersion in a Doppler-broadened A-type three level system by resonant stimulated Raman spectroscopy with homodyne detection. Through studying the dressed state energies of the system, it is found that the absorption and dispersion satisfy the Kramers-Kronig relation. The absorption and dispersion spectra calculated by employing this relation agree well with our experimental observations.展开更多
The photoabsorption cross sections of condensed atoms and molecules have proven to be dependent notonly on the imaginary parts but also on the real parts of the polarizabilities due to the strong interatomic interacti...The photoabsorption cross sections of condensed atoms and molecules have proven to be dependent notonly on the imaginary parts but also on the real parts of the polarizabilities due to the strong interatomic interactionsin condensed environment.The real parts of the polarizabilities calculated usually by using the famous Kramers-Kronigtransformation (KKT) from the photoabsorption cross sections of the isolated atoms are very sensitive to the accuracyof the implementation method of the infinite integral in the KKT.The influence of the integral instability of the KKTand the real part of the polarizability on the variation of the photoabsorption cross sections with the number densityand the structure of the condensed matter has been studied in the present work for the first time.The conclusion is thatthe integration method with interpolation has given more reasonable results than the direct truncation method if someappropriate interpolation functions have been used.Some notes and conclusions have also been given for the applicationsof the alternative coupled expressions of photoabsorption cross sections.展开更多
We propose and investigate the use of a Kramers–Kronig(KK) receiver in a single sideband orthogonal frequency division multiplexing radio over fiber(SSB-OFDM-RoF) link based on an optical remote heterodyne solution. ...We propose and investigate the use of a Kramers–Kronig(KK) receiver in a single sideband orthogonal frequency division multiplexing radio over fiber(SSB-OFDM-RoF) link based on an optical remote heterodyne solution. This scheme is effective in eliminating the signal-to-signal beating interference introduced by square-law detection of a photo-detector in an SSB-OFDM-RoF link. We extensively study the influences of different carrier-to-signal power ratios(CSPRs), laser linewidths, and transmission distances on our proposed scheme. It is proved that the KK-based receiver can reduce optimal CSPR by more than 5 dB and provide about 1.1 dB gain over the conventional mixer-based receiver scheme with CSPR of 11 dB after 75 km fiber transmission.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2013CB922002 and 2010CB922904)the National Natural Science Foundation of China(Grant Nos.11274376 and 61308011)the Natural Science Foundation of Hebei Province,China(Grant No.A2015205161)
文摘We measure the absorption and dispersion in a Doppler-broadened A-type three level system by resonant stimulated Raman spectroscopy with homodyne detection. Through studying the dressed state energies of the system, it is found that the absorption and dispersion satisfy the Kramers-Kronig relation. The absorption and dispersion spectra calculated by employing this relation agree well with our experimental observations.
基金Supported by the Natural Science Foundations of Ludong University under Grant Nos.22270301 and L20072804
文摘The photoabsorption cross sections of condensed atoms and molecules have proven to be dependent notonly on the imaginary parts but also on the real parts of the polarizabilities due to the strong interatomic interactionsin condensed environment.The real parts of the polarizabilities calculated usually by using the famous Kramers-Kronigtransformation (KKT) from the photoabsorption cross sections of the isolated atoms are very sensitive to the accuracyof the implementation method of the infinite integral in the KKT.The influence of the integral instability of the KKTand the real part of the polarizability on the variation of the photoabsorption cross sections with the number densityand the structure of the condensed matter has been studied in the present work for the first time.The conclusion is thatthe integration method with interpolation has given more reasonable results than the direct truncation method if someappropriate interpolation functions have been used.Some notes and conclusions have also been given for the applicationsof the alternative coupled expressions of photoabsorption cross sections.
基金supported by the National Natural Science Foundation of China(Nos.61420106011 and 61471088)the Fundamental Research Funds for the Central Universities(No.ZYGX2016J014)
文摘We propose and investigate the use of a Kramers–Kronig(KK) receiver in a single sideband orthogonal frequency division multiplexing radio over fiber(SSB-OFDM-RoF) link based on an optical remote heterodyne solution. This scheme is effective in eliminating the signal-to-signal beating interference introduced by square-law detection of a photo-detector in an SSB-OFDM-RoF link. We extensively study the influences of different carrier-to-signal power ratios(CSPRs), laser linewidths, and transmission distances on our proposed scheme. It is proved that the KK-based receiver can reduce optimal CSPR by more than 5 dB and provide about 1.1 dB gain over the conventional mixer-based receiver scheme with CSPR of 11 dB after 75 km fiber transmission.
