Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of th...Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.展开更多
We apply two-photon resonant nondegenerate four-wave mixing with a resonant intermediate state for the obser- vation of Rydberg states in sodium vapour. The broadening and shift of the sodium 3S- 11D transition pertur...We apply two-photon resonant nondegenerate four-wave mixing with a resonant intermediate state for the obser- vation of Rydberg states in sodium vapour. The broadening and shift of the sodium 3S- 11D transition perturbed by argon are investigated. This technique can achieve Doppler-free resolution of narrow spectral structures of Rydberg levels if lasers with narrow bandwidths are employed.展开更多
We demonstrated a phase-sensitive method for studying the Raman-enhanced nondegenerate four-wave mixing(RENFWM).The reference beam is another four-wave mixing signal,which propagates along the same optical path as the...We demonstrated a phase-sensitive method for studying the Raman-enhanced nondegenerate four-wave mixing(RENFWM).The reference beam is another four-wave mixing signal,which propagates along the same optical path as the RENFWM signal.This method is used for studying the phase dispersion of the third-ordersusceptibility X^((3))and for the optical heterodyne detection of the RENFWM signal.展开更多
Based on the interference between two two-photon processes,we reported a four-level ultrafast modulation spectroscopy in Na vapor,where 3S,3P,5S,and 4D formed a four-level system.We studied the temporal behavior of th...Based on the interference between two two-photon processes,we reported a four-level ultrafast modulation spectroscopy in Na vapor,where 3S,3P,5S,and 4D formed a four-level system.We studied the temporal behavior of the four-wave mixing signal intensity and obtained signal modulation with period 25fs,corresponding to the splitting between 5s and 4D.This technique can achieve Doppler-free precision in the measurement of the energy level splitting between two excited states which are dipolar forbidden from the ground state.展开更多
The effects of field correlation on Raman-enhanced nondegenerate four-wave mixing(REN-FWM)have been investigated by examining the RENFWM spectra as a function of time delay between two beams.An enhancement of the rati...The effects of field correlation on Raman-enhanced nondegenerate four-wave mixing(REN-FWM)have been investigated by examining the RENFWM spectra as a function of time delay between two beams.An enhancement of the ratio between the resonant and nonresonant REN-FWM signal intensities was found as the time delay was increased when the laser had broadband linewidth.展开更多
The first observation of collisional narrowing by time-resolved degenerate four-wave mixing has been reported. The velocity-changing collision cross section of Na in Ar De obtained is 5.6 × 10^(-15)cm^(2).
基金Project supported by the National Natural Science foundation of China （Grant Nos 10174096 and 10374113） and the National Program for Basic Research in China （Grant No 001CB309301）.
文摘Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.
基金Supported by the National Natural Science Foundation of China under Grant No.19874080。
文摘We apply two-photon resonant nondegenerate four-wave mixing with a resonant intermediate state for the obser- vation of Rydberg states in sodium vapour. The broadening and shift of the sodium 3S- 11D transition perturbed by argon are investigated. This technique can achieve Doppler-free resolution of narrow spectral structures of Rydberg levels if lasers with narrow bandwidths are employed.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19874080 and 69578030.
文摘We demonstrated a phase-sensitive method for studying the Raman-enhanced nondegenerate four-wave mixing(RENFWM).The reference beam is another four-wave mixing signal,which propagates along the same optical path as the RENFWM signal.This method is used for studying the phase dispersion of the third-ordersusceptibility X^((3))and for the optical heterodyne detection of the RENFWM signal.
基金Supported by the National Natural Science Foundation of China under Grant No.69578030.
文摘Based on the interference between two two-photon processes,we reported a four-level ultrafast modulation spectroscopy in Na vapor,where 3S,3P,5S,and 4D formed a four-level system.We studied the temporal behavior of the four-wave mixing signal intensity and obtained signal modulation with period 25fs,corresponding to the splitting between 5s and 4D.This technique can achieve Doppler-free precision in the measurement of the energy level splitting between two excited states which are dipolar forbidden from the ground state.
基金Supported by the National Natural Science Foundation of China under Grant No.19474067the Climbing Program from the Chinese Commission of Science and Technology.
文摘The effects of field correlation on Raman-enhanced nondegenerate four-wave mixing(REN-FWM)have been investigated by examining the RENFWM spectra as a function of time delay between two beams.An enhancement of the ratio between the resonant and nonresonant REN-FWM signal intensities was found as the time delay was increased when the laser had broadband linewidth.
文摘The first observation of collisional narrowing by time-resolved degenerate four-wave mixing has been reported. The velocity-changing collision cross section of Na in Ar De obtained is 5.6 × 10^(-15)cm^(2).
