physica status solidi (b)

Induced absorption due to exciton‐biexciton transitions in CuCl

Albert Bivas, Vu Duy Phach, B. Hönerlage, J. B. Grün

Published Nov 1, 1977• 45 citations

Abstract

Abstract The induced absorption due to exciton‐biexciton transitions is observed in CuCl with an experimental set‐up using two dye lasers. The shape of the absorption band is studied. The oscillator strength per exciton of this absorption is estimated and compared to theoretical evaluations. The excitation spectrum of this induced absorption is also measured and its features are tentatively explained by the existence of a superficial layer on the samples, where excitons have a very short lifetime.

DOI: 10.1002/pssb.2220840126

Related papers

Optical Gain and Induced Absorption in High‐Density Exciton System in CuCl

J. M. Hvam, Albert Bivas

physica status solidi (b)Sep 1, 19807 citations

Time-resolved exciton-biexciton transitions in CuCl

R. Lévy, B. Hönerlage, J. B. Grün

The time-resolved induced absorption due to exciton-biexciton transitions is observed in CuCl, using an intense ultraviolet picosecond pulse excitation and a picosecond continuum as a probe beam. In the same experimental conditions, time-resolved luminescence is also recorded. We have obtained information on the time evolution of the exciton and biexciton populations. Studying the dynamic equations of the system, we have determined the radiative lifetimes of biexcitons and transverse excitons.

Physical review. B, Condensed matterFeb 15, 197940 citations

Dynamics of induced absorption and gain related to excitonic excitation in CuCl

R. Leonelli, A. Manar, J. B. Grün +1 more

Physical review. B, Condensed matterFeb 15, 199213 citations

Optical transitions from the lowest to higher exciton and biexciton Rydberg states in CuCl

Kensuke Miyajima, K. Sakaniwa, M. Sugawara

Physical review. B./Physical review. BNov 28, 20164 citations

Biexciton resonant two‐photon absorption in CuCl

Vu Duy Phach, Albert Bivas, B. Hönerlage +1 more

Abstract In studying the two‐photon absorption (TPA) of the biexciton in CuCl by using two different light sources, interesting information is obtained. The biexciton ground‐state energy is determined accurately; its symmetry is experimentally verified; a value for the TPA coefficient is deduced and compared with a theoretical evaluation; a lineshape analysis enables us to discuss the damping constants of the exciton and biexciton states involved.

physica status solidi (b)Dec 1, 197781 citations

Transient phase-space filling by resonantly excited exciton interactions in CuCl

R. Leonelli, J. C. Mathae, J. M. Hvam +2 more

Physical Review LettersMar 30, 198715 citations

physica status solidi (b)

Induced absorption due to exciton‐biexciton transitions in CuCl

Albert Bivas, Vu Duy Phach, B. Hönerlage, J. B. Grün

Published Nov 1, 1977• 45 citations

Publisher

Abstract

DOI: 10.1002/pssb.2220840126

Related papers

Optical Gain and Induced Absorption in High‐Density Exciton System in CuCl

J. M. Hvam, Albert Bivas

Abstract In CuCl at 1.7 K optical gain/absorption spectra are recorded in the spectral range of bound exciton and biexciton emission. Energy, effective temperature, and oscillator strength of biexcitons are determined. The observed kinetics indicates that the total pair density in the exciton‐biexciton system is pinned at about 1.6 × 1016 cm−3 for all excitation densities above 10 kW/cm2. At intense excitation, a Fano‐interference is observed between a discrete impurity absorption line and a continuum absorption tail. The latter is followed by a band of positive gain towards lower photon energies.Abstract In CuCl at 1.7 K optical gain/absorption spectra are recorded in the spectral range of bound exciton and biexciton emission. Energy, effective temperature, and oscillator strength of biexcitons are determined. The observed kinetics indicates that the total pair density in the exciton‐biexciton system is pinned at about 1.6 × 1016 cm−3 for all excitation densities above 10 kW/cm2. At intense excitation, a Fano‐interference is observed between a discrete impurity absorption line and a continuum absorption tail. The latter is followed by a band of positive gain towards lower photon energies.

physica status solidi (b)Sep 1, 19807 citations

Time-resolved exciton-biexciton transitions in CuCl

R. Lévy, B. Hönerlage, J. B. Grün

Physical review. B, Condensed matterFeb 15, 197940 citations

Dynamics of induced absorption and gain related to excitonic excitation in CuCl

R. Leonelli, A. Manar, J. B. Grün +1 more

We present a thorough investigation of the different relaxation channels opened in a strongly interacting system of excitonic quasiparticles in CuCl for density regimes ranging up to 50 MW/ ${\mathrm{cm}}^{2}$ . A spectrally narrow pump beam consisting of 30-ps pulses is tuned around one-half the biexciton energy. It creates an initial distribution of biexcitons through resonant two-photon absorption. A spectrally broad probe beam made of pulses that also have 30-ps duration monitors the excitation-induced variation of the transmission spectrum of CuCl samples near the ${\mathit{Z}}_{3}$ exciton resonance. Coherent processes corresponding to parametric emissions of various orders are observed. Absorption and gain bands that reflect the evolution of biexciton and exciton populations on their respective dispersion curves are followed as functions of the time delay between pump and probe pulses.We present a thorough investigation of the different relaxation channels opened in a strongly interacting system of excitonic quasiparticles in CuCl for density regimes ranging up to 50 MW/${\mathrm{cm}}^{2}$. A spectrally narrow pump beam consisting of 30-ps pulses is tuned around one-half the biexciton energy. It creates an initial distribution of biexcitons through resonant two-photon absorption. A spectrally broad probe beam made of pulses that also have 30-ps duration monitors the excitation-induced variation of the transmission spectrum of CuCl samples near the ${\mathit{Z}}_{3}$ exciton resonance. Coherent processes corresponding to parametric emissions of various orders are observed. Absorption and gain bands that reflect the evolution of biexciton and exciton populations on their respective dispersion curves are followed as functions of the time delay between pump and probe pulses.

Physical review. B, Condensed matterFeb 15, 199213 citations

Optical transitions from the lowest to higher exciton and biexciton Rydberg states in CuCl

Kensuke Miyajima, K. Sakaniwa, M. Sugawara

We measured the optical transitions due to the internal energy levels of an exciton and biexciton in a CuCl single crystal using pump-probe spectroscopy. The transient absorption bands due to the transitions from the $1s$ to $2p$ and from the $1s$ to $3p$ exciton states were observed at 3 K, which is consistent with their reported energies. Simultaneously, the transient absorption peak due to the biexciton was observed, which corresponds to a transition from the lowest state (composed of two $1s$ excitons) to higher states (composed of $1s$ and $2p$ excitons). The value of the observed biexciton peak energy was reasonable considering the hydrogen molecule orbitals and the electron-to-hole effective mass ratio. In addition, the transient absorption peaks were broadened at 77 K, because of the increase in the homogeneous width of the $2p$ exciton state. The transient absorption spectrum was almost completely determined by this width. Our findings are of importance with regard to the optical phenomena in the infrared region related to the quantum coherence of excitons and biexcitons in semiconductors.We measured the optical transitions due to the internal energy levels of an exciton and biexciton in a CuCl single crystal using pump-probe spectroscopy. The transient absorption bands due to the transitions from the $1s$ to $2p$ and from the $1s$ to $3p$ exciton states were observed at 3 K, which is consistent with their reported energies. Simultaneously, the transient absorption peak due to the biexciton was observed, which corresponds to a transition from the lowest state (composed of two $1s$ excitons) to higher states (composed of $1s$ and $2p$ excitons). The value of the observed biexciton peak energy was reasonable considering the hydrogen molecule orbitals and the electron-to-hole effective mass ratio. In addition, the transient absorption peaks were broadened at 77 K, because of the increase in the homogeneous width of the $2p$ exciton state. The transient absorption spectrum was almost completely determined by this width. Our findings are of importance with regard to the optical phenomena in the infrared region related to the quantum coherence of excitons and biexcitons in semiconductors.

Physical review. B./Physical review. BNov 28, 20164 citations

Biexciton resonant two‐photon absorption in CuCl

Vu Duy Phach, Albert Bivas, B. Hönerlage +1 more

physica status solidi (b)Dec 1, 197781 citations

Transient phase-space filling by resonantly excited exciton interactions in CuCl

R. Leonelli, J. C. Mathae, J. M. Hvam +2 more

We report time-resolved induced-absorption measurements near the ${\mathrm{Z}}_{3}$ -exciton resonance in CuCl platelets which were excited at the biexciton resonance by laser pulses of 30-ps duration. We find that the excitons created through biexciton decay induce exponential tails on their absorption line. This effect can be explained in terms of exciton phase-space filling if quantum fluctuations in the local exciton density are taken into account.We report time-resolved induced-absorption measurements near the ${\mathrm{Z}}_{3}$-exciton resonance in CuCl platelets which were excited at the biexciton resonance by laser pulses of 30-ps duration. We find that the excitons created through biexciton decay induce exponential tails on their absorption line. This effect can be explained in terms of exciton phase-space filling if quantum fluctuations in the local exciton density are taken into account.

Physical Review LettersMar 30, 198715 citations

We present a thorough investigation of the different relaxation channels opened in a strongly interacting system of excitonic quasiparticles in CuCl for density regimes ranging up to 50 MW/

{\mathrm{cm}}^{2}

. A spectrally narrow pump beam consisting of 30-ps pulses is tuned around one-half the biexciton energy. It creates an initial distribution of biexcitons through resonant two-photon absorption. A spectrally broad probe beam made of pulses that also have 30-ps duration monitors the excitation-induced variation of the transmission spectrum of CuCl samples near the

{\mathit{Z}}_{3}

exciton resonance. Coherent processes corresponding to parametric emissions of various orders are observed. Absorption and gain bands that reflect the evolution of biexciton and exciton populations on their respective dispersion curves are followed as functions of the time delay between pump and probe pulses.

1s

2p

and from the

1s

3p

exciton states were observed at 3 K, which is consistent with their reported energies. Simultaneously, the transient absorption peak due to the biexciton was observed, which corresponds to a transition from the lowest state (composed of two

1s

excitons) to higher states (composed of

1s

and

2p

excitons). The value of the observed biexciton peak energy was reasonable considering the hydrogen molecule orbitals and the electron-to-hole effective mass ratio. In addition, the transient absorption peaks were broadened at 77 K, because of the increase in the homogeneous width of the

2p

exciton state. The transient absorption spectrum was almost completely determined by this width. Our findings are of importance with regard to the optical phenomena in the infrared region related to the quantum coherence of excitons and biexcitons in semiconductors.

We report time-resolved induced-absorption measurements near the

{\mathrm{Z}}_{3}

-exciton resonance in CuCl platelets which were excited at the biexciton resonance by laser pulses of 30-ps duration. We find that the excitons created through biexciton decay induce exponential tails on their absorption line. This effect can be explained in terms of exciton phase-space filling if quantum fluctuations in the local exciton density are taken into account.