Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Topical Meeting on Optical Bistability (OB)

Internal Feedback Mechanisms of Optoelectronic Bistability in Cadmium Sulfide

Sergey Viktorovich Bogdanov, Vadim G. Lyssenko

Published Jan 1, 1988• 0 citations
Publisher

Abstract

Optical bistability caused by thermal heating is observed when the CdS crystal is excited near the I2 bound exciton absorption line [1]. Impact ionization of free and bound excitons occurs in the crystal upon its illumination in electric field. The probability of impact ionization depends in a threshold way on exciton and free carrier concentration. At a certain field dependent carrier concentratiοn avalanche occurs, the electric current therewith increases the crystal temperature by 5-20 K [2] which is followed by a red I2 shift. The shift leads to an increase in absorption, carrier density and current. Therefore, feedback results from impact ionization current heating the crystal (Fig. 1).

DOI
10.1364/obi.1988.the.10

Related papers

INTERNAL FEEDBACK MECHANISMS OF OPTOELECTRONIC BISTABILITY IN CADMIUM SULFIDE

Sergey Viktorovich Bogdanov, Vadim G. Lyssenko

Two mechanisms of internal feedback in cadmium sulfide in electric field have been studied, namely, thermal shift of absorption lines and electron state transformation due to multiparticle interaction in the high carrier concentration system.

Le Journal de Physique Colloques•Jun 1, 1988•0 citations

Cavityless optical bistability due to light-induced absorption in cadmium sulfide

M. Dagenais, Wayne F. Sharfin

Cavityless, whole-beam optical bistability in thin, uncoated cadmium sulfide platelets is observed at milliwatt power levels when a cw laser is tuned near a sharp extrinsic excitonic resonance in cadmium sulfide (the I2 bound exciton). Very large contrast ratios between the on and off states are measured. The detuning and temperature dependence of the bistability results are reported. Preliminary transient measurements are also discussed.

Applied Physics Letters•Aug 1, 1984•70 citations

Low Power Optical Bistability Near Bound Excitons in Cadmium Sulfide

M. Dagenais, H. G. Winful

The I2 bound exciton in cadmium sulfide has a giant oscillator strength of 6. It decays mostly radiatively in 500 psec. Such a large oscillator strength leads to a very large transition dipole moment and to very large nonlinear effects off-resonance. At 2K, this sytem saturates like an inhomogeneously broadened system for intensities up to 30 times the saturation intensity. The transition linewidth is 7.5 GHz. In a tight focusing geometry, only 3.6 μW is required to see the onset of saturation. This corresponds to a measured saturation intensity of about 60 W/cm2. The linear absorption coefficient right at the resonance peak was measured to be 3.2 x 103 cm-1. At higher temperatures, the transition linewidth broadens and the line becomes more and more homogeneously broadened because of phonon interaction. At intensities above 50 times the saturation intensity, the absorption coefficient stops decreasing and then starts increasing. At these high intensities, thermal effects appear to play a significant role in shifting the free and bound exciton resonances toward lower energies. At intensities less than 20 times the saturation intensity, thermal effects are believed to be insignificant in our saturation measurements.

Topical Meeting on Optical Bistability (OB)•Jan 1, 1983•0 citations

CdS self-electrooptic effect device: electrooptic modulation and optical bistability at 514nm

A. Witt, M. Wegener, Claus F. Klingshirn +3 more

It has been demonstrated that thin CdS crystal platelets at room temperature may exhibit all-optical bistability under illumination with the 514nm line of an Ar+-laser1. In this case the local heating of the sample leads to induced absorption optical bistability. In the present paper we evaporate metallic contacts on CdS crystals and apply an external bias voltage. The carriers created by the incoming light lead to a photo-current which in turn increases the temperature of the sample by electrical power via Joule's heat and thereby changes the optical properties 2,3.

Topical Meeting on Optical Bistability (OB)•Jan 1, 1988•0 citations

Optical Nonlinearity and Bistability in the Bound Exciton Energy Range of CdS

Thomas Honig, Juergen Gutowski

Abstract Under high excitation conditions thick CdS samples show pronounced broad‐band nonlinear transmission in the bound exciton region and up to a wavelength of about 515 nm at cryo‐temperatures. This behavior is only explainable in a model based on impurity neutralization and bound exciton creation. The suitability of these nonlinearities to yield optical bistability will be shown. Bistable operation is investigated in dependence of crystal thickness, impurity concentration, excitation density, wavelength, and temperature. A strong correlation to acceptor‐bound exciton generation is obtained, and the explanation of this bistable operation fits well with that of the above mentioned transmission behavior.

physica status solidi (b)•Dec 1, 1988•10 citations

Composite Logic Gate Element and Multiplexer for Optical Computing and Optical Communication

Joseph W. Haus, C. M. Bowden, Chi C. Sung

Mirrorless (cavityless) optical bistability (OB), due to temperature-dependent renormalization of the absorption peak of the bound exciton resonance in CdS has been observed and interpreted1 in terms of coupling between the internal field intensity and the temperature in the nonlinear material. It was shown2 that the heat conductivity boundary conditions determine the conditions for bistability of a sample of the material. In fact, we showed earlier that when the boundary conditions at the ends of the sample are such that the heat resistance at the exit end HL = h1/3 where ho is the heat resistance at the entrance face, two hysteresis curves result, one clockwise with increasing input intensity at lower incident fields due to increasing absorption and the other at higher field values due to decreasing absorption which is counter-clockwise, Figures 1a and 1b.

Topical Meeting on Optical Bistability (OB)•Jan 1, 1985•1 citation
Optical bistability caused by thermal heating is observed when the CdS crystal is excited near the I2 bound exciton absorption line [1]. Impact ionization of free and bound excitons occurs in the crystal upon its illumination in electric field. The probability of impact ionization depends in a threshold way on exciton and free carrier concentration. At a certain field dependent carrier concentratiοn avalanche occurs, the electric current therewith increases the crystal temperature by 5-20 K [2] which is followed by a red I2 shift. The shift leads to an increase in absorption, carrier density and current. Therefore, feedback results from impact ionization current heating the crystal (Fig. 1).
The I2 bound exciton in cadmium sulfide has a giant oscillator strength of 6. It decays mostly radiatively in 500 psec. Such a large oscillator strength leads to a very large transition dipole moment and to very large nonlinear effects off-resonance. At 2K, this sytem saturates like an inhomogeneously broadened system for intensities up to 30 times the saturation intensity. The transition linewidth is 7.5 GHz. In a tight focusing geometry, only 3.6 μW is required to see the onset of saturation. This corresponds to a measured saturation intensity of about 60 W/cm2. The linear absorption coefficient right at the resonance peak was measured to be 3.2 x 103 cm-1. At higher temperatures, the transition linewidth broadens and the line becomes more and more homogeneously broadened because of phonon interaction. At intensities above 50 times the saturation intensity, the absorption coefficient stops decreasing and then starts increasing. At these high intensities, thermal effects appear to play a significant role in shifting the free and bound exciton resonances toward lower energies. At intensities less than 20 times the saturation intensity, thermal effects are believed to be insignificant in our saturation measurements.
It has been demonstrated that thin CdS crystal platelets at room temperature may exhibit all-optical bistability under illumination with the 514nm line of an Ar+-laser1. In this case the local heating of the sample leads to induced absorption optical bistability. In the present paper we evaporate metallic contacts on CdS crystals and apply an external bias voltage. The carriers created by the incoming light lead to a photo-current which in turn increases the temperature of the sample by electrical power via Joule's heat and thereby changes the optical properties 2,3.
Abstract Under high excitation conditions thick CdS samples show pronounced broad‐band nonlinear transmission in the bound exciton region and up to a wavelength of about 515 nm at cryo‐temperatures. This behavior is only explainable in a model based on impurity neutralization and bound exciton creation. The suitability of these nonlinearities to yield optical bistability will be shown. Bistable operation is investigated in dependence of crystal thickness, impurity concentration, excitation density, wavelength, and temperature. A strong correlation to acceptor‐bound exciton generation is obtained, and the explanation of this bistable operation fits well with that of the above mentioned transmission behavior.
Mirrorless (cavityless) optical bistability (OB), due to temperature-dependent renormalization of the absorption peak of the bound exciton resonance in CdS has been observed and interpreted1 in terms of coupling between the internal field intensity and the temperature in the nonlinear material. It was shown2 that the heat conductivity boundary conditions determine the conditions for bistability of a sample of the material. In fact, we showed earlier that when the boundary conditions at the ends of the sample are such that the heat resistance at the exit end HL = h1/3 where ho is the heat resistance at the entrance face, two hysteresis curves result, one clockwise with increasing input intensity at lower incident fields due to increasing absorption and the other at higher field values due to decreasing absorption which is counter-clockwise, Figures 1a and 1b.