We show that the optical dephasing time ${T}_{2}$ can be obtained from a measurement of the time delay ${T}_{0}$ between two shifts of $\ifmmode\pm\else\textpm\fi{}\frac{\ensuremath{\pi}}{2}$ in the phase of the exciting laser for which a null occurs in the jump in the nonlinear transmission through a sample. The phase shift is imposed upon a single-mode cw laser by applying a rectangular voltage pulse to an electro-optic phase modulator placed in the laser beam. The time delay at which the null occurs is proportional to ${T}_{2}$ , which is given by the expression ${T}_{2}=(\frac{2}{\mathrm{ln}2}){T}_{0}$ . The method is demonstrated in atomic sodium and iodine vapor and the separation of third-order optical transients from linear transients induced by the phase shift is discussed. An analytic expression for the jump in the nonlinear transmission, induced by the second phase shift, as well as for the transient in transmission following a single phase shift of a laser which weakly saturates an optically thin sample is derived. It is also shown that optical dephasing rates may be inferred from the variation of the integral of the transmitted light in a double-phase-switching experiment.We show that the optical dephasing time ${T}_{2}$ can be obtained from a measurement of the time delay ${T}_{0}$ between two shifts of $\ifmmode\pm\else\textpm\fi{}\frac{\ensuremath{\pi}}{2}$ in the phase of the exciting laser for which a null occurs in the jump in the nonlinear transmission through a sample. The phase shift is imposed upon a single-mode cw laser by applying a rectangular voltage pulse to an electro-optic phase modulator placed in the laser beam. The time delay at which the null occurs is proportional to ${T}_{2}$, which is given by the expression ${T}_{2}=(\frac{2}{\mathrm{ln}2}){T}_{0}$. The method is demonstrated in atomic sodium and iodine vapor and the separation of third-order optical transients from linear transients induced by the phase shift is discussed. An analytic expression for the jump in the nonlinear transmission, induced by the second phase shift, as well as for the transient in transmission following a single phase shift of a laser which weakly saturates an optically thin sample is derived. It is also shown that optical dephasing rates may be inferred from the variation of the integral of the transmitted light in a double-phase-switching experiment.

Physical Review AJul 1, 19835 citations

OPTICAL COHERENT TRANSIENTS

M. D. Levenson, Satoru S. Kano

Elsevier eBooksJan 1, 19882 citations

Homodyne detection of a two-photon resonance assisted by cooperative emission

Chetan Sriram Madasu, Chang Chi Kwong, David Wilkowski +1 more

Focusing on the transient regime, we explore atomic two-photon spectroscopy with self-aligned homodyne interferometry in a $\mathrm{\ensuremath{\Lambda}}$ system with large optical depth. The two light sources at the origin of the interference are the single-photon transient transmission of the probe and the slow light of the electromagnetically induced transparency. By abruptly switching off the probe laser (flash effect), the transient transmission signal is reinforced by cooperativity, showing enhanced sensitivity to the two-photon frequency detuning. If the probe laser is periodically switched on and off, the amplitude of the transmission signal varies and remains large even for high modulation frequency. This technique has potential applications in sensing, such as magnetometry and velocimetry, and in coherent population trapping clocks.Focusing on the transient regime, we explore atomic two-photon spectroscopy with self-aligned homodyne interferometry in a $\mathrm{\ensuremath{\Lambda}}$ system with large optical depth. The two light sources at the origin of the interference are the single-photon transient transmission of the probe and the slow light of the electromagnetically induced transparency. By abruptly switching off the probe laser (flash effect), the transient transmission signal is reinforced by cooperativity, showing enhanced sensitivity to the two-photon frequency detuning. If the probe laser is periodically switched on and off, the amplitude of the transmission signal varies and remains large even for high modulation frequency. This technique has potential applications in sensing, such as magnetometry and velocimetry, and in coherent population trapping clocks.

arXiv:2105.12440Physical Review AJan 19, 20221 citation

Transient electromagnetically induced transparency spectroscopy of 87Rb atoms in buffer gas

Zi-Shan Xu, Han-Mu Wang, Zeng-Li Ba +1 more

We study the transient response dynamics of 87Rb atomic vapor buffered in 8 torr Ne gas through an electromagnetically induced transparency configured in Λ-scheme. Experimentally, the temporal transmission spectra versus probe detuning by switching on and off the coupling one show complex structures. The transmitted probe light intensity drops to a minimum value when the coupling light turns off, showing a strong absorption. Even at the moment of turning on the coupling light at a subsequent delayed time, the atomic medium shows a fast transient response. To account for the transient switching feature, in the time-dependent optical Bloch equation, we must take the transverse relaxation dephasing process of atomic vapor into account, as well as the fluorescence relaxation along with the optical absorption. This work supplies a technique to quantify the transverse relaxation time scale and to sensitively monitor its variation along the environment by observing the transient dynamics of coherent medium, which is helpful in characterizing the coherent feature of the atomic medium.We study the transient response dynamics of 87Rb atomic vapor buffered in 8 torr Ne gas through an electromagnetically induced transparency configured in Λ-scheme. Experimentally, the temporal transmission spectra versus probe detuning by switching on and off the coupling one show complex structures. The transmitted probe light intensity drops to a minimum value when the coupling light turns off, showing a strong absorption. Even at the moment of turning on the coupling light at a subsequent delayed time, the atomic medium shows a fast transient response. To account for the transient switching feature, in the time-dependent optical Bloch equation, we must take the transverse relaxation dephasing process of atomic vapor into account, as well as the fluorescence relaxation along with the optical absorption. This work supplies a technique to quantify the transverse relaxation time scale and to sensitively monitor its variation along the environment by observing the transient dynamics of coherent medium, which is helpful in characterizing the coherent feature of the atomic medium.

Chinese Physics BDec 31, 20215 citations

Coherent optical transients observed by polarization switching

M. D. Levenson

Chemical Physics LettersJul 1, 19792 citations

We show that the optical dephasing time

{T}_{2}

can be obtained from a measurement of the time delay

{T}_{0}

between two shifts of $\ifmmode\pm\else\textpm\fi{}\frac{\ensuremath{\pi}}{2}$ in the phase of the exciting laser for which a null occurs in the jump in the nonlinear transmission through a sample. The phase shift is imposed upon a single-mode cw laser by applying a rectangular voltage pulse to an electro-optic phase modulator placed in the laser beam. The time delay at which the null occurs is proportional to

{T}_{2}

, which is given by the expression

{T}_{2}=(\frac{2}{\mathrm{ln}2}){T}_{0}

. The method is demonstrated in atomic sodium and iodine vapor and the separation of third-order optical transients from linear transients induced by the phase shift is discussed. An analytic expression for the jump in the nonlinear transmission, induced by the second phase shift, as well as for the transient in transmission following a single phase shift of a laser which weakly saturates an optically thin sample is derived. It is also shown that optical dephasing rates may be inferred from the variation of the integral of the transmitted light in a double-phase-switching experiment.