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

IEEE Journal of Quantum Electronics

Induced nanosecond absorption in InP:Fe

P. U. Halter, Jean Claude Fabre, Gérald Roosen

Published Aug 1, 1990• 2 citations
Publisher

Abstract

Induced absorption was observed in an InP:Fe crystal under nanosecond pulse illumination at 1.06- mu m wavelength. The maximum induced absorption was 0.05 cm/sup -1/ when probed at a 1.06- mu m wavelength and 0.30 cm/sup -1/ when probed at a 1.30- mu m wavelength. The kinetics are studied together with the photocurrent giving the recombination times of holes (100 ns) at room temperature and an estimate for that of electrons (0.5 ns). The induced absorption is attributed to a population redistribution of the different iron impurity states. Computer simulations are able to explain all the features found in the experiments and give values for the photoionization cross sections, in particular for the unknown cross section Fe/sup 2+*/ to Fe/sup 3+/+e/sup -/.>

DOI
10.1109/3.59692

Related papers

Kinetics of induced nanosecond absorption in photorefractive InP:Fe

P. U. Halter, Jean Claude Fabre, Gérald Roosen

For understanding and optimization of the photo refractive gain it is important to know the basic parameters of photo-ionization and recombination processes. In the nanosecond regime the pulse energies required for maximum coupling gain in semiconductors easily reach the limit for saturation of the deep centers. especially if one of the recombination times is larger than the pulse duration. In that case, induced absorption (or bleaching) will appear due to a redistribution of the population of the different levels of the deep center and counterbalance photorefractive amplification. The present simultaneous study of the kinetics of the induced absorption and the photocurrent in an InP:Fe sample reveals a number of interesting parameters like electron and hole recombination times, ionization cross sections and Fe2+/Fe3+ concentrations.

Photorefractive Effects, Materials, and Devices•Jan 1, 1990•0 citations

Photorefractive effect in InP:Fe dominated by holes at room temperature: influence of the indirect transitions

Cafer Özkul, S. Jamet, Philippe Gravey +2 more

Iron-ion concentrations have been determined from measurements of the photoinduced-grating erasure times. We checked the accuracy of this method by performing two-wave mixing experiments at λ = 1.32 μm without an applied field. After verifying the fit of the extended single-defect model with indirect transitions and the two-wave mixing gain data at λ = 1.06 μm, we conclude that the indirect transitions involving the excited state of Fe2+ can induce a reduction of the photorefractive effect in InP:Fe when the dominant photocarriers are holes at room temperature.

Journal of the Optical Society of America B•Sep 1, 1994•4 citations

Thermally induced hole-electron competition in photorefractive InP:Fe due to the Fe2+ excited state

Philippe Delaye, P. U. Halter, Gérald Roosen

The photorefractive coupling gain is limited in InP:Fe even if there is no direct hole-electron competition. One has to take into account the excited state of Fe2+ (5T2) with its strong thermal emission(1/βth≂100 ns). This leads to an indirect hole-electron competition mechanism and helps to explain experimental results. This coupling gain reduction is inherent to the nature of the Fe dopant in InP for wavelengths below 1.2 μm and temperature above 170 K.

Applied Physics Letters•Jul 23, 1990•15 citations

Net gain in photorefractive InP:Fe at λ=1.32 μm without an applied field

Jefferson Strait, Jason D. Reed, A. Saunders +2 more

We have observed two-beam coupling gain (0.273 cm−1) that exceeds absorption (0.145 cm−1) in InP:Fe without applying an external field at λ=1.32 μm. Measurements of the gain coefficient as a function of grating spacing fit the photorefractive theory for simultaneous electron-hole transport, with the effective density of traps NE = (3.86 ± 1.1)NE=(3.86±1.1)× 1015 cm−3 and ξ, the factor that accounts for competition between electrons and holes, equaling −0.729±0.026. Absorption measurements, combined with the photoionization cross sections of electrons and holes, confirm these results. The agreement between theory and experiment suggests how to choose impurity concentrations that optimize net gain.

Applied Physics Letters•Sep 3, 1990•9 citations

Continuous-wave two-beam coupling in InP:Fe and GaAs: evidence for thermal hole–electron competition in InP:Fe

Philippe Delaye, P. U. Halter, Gérald Roosen

We show that even if there is no direct hole–electron competition in InP:Fe the gain is lower than expected. We attribute this reduction of the gain to a thermally induced hole–electron competition that involves the excited state of Fe2+ (5T2). We present a new model for the photorefractive effect in InP:Fe, which we use to interpret our beam-coupling results. Some material parameters of the InP:Fe sample and particularly of the excited state are deduced. The same energy-transfer measurements conducted in GaAs give us the ratio of hole and electron photoionization cross sections.

Journal of the Optical Society of America B•Dec 1, 1990•32 citations

Photorefractive solitons and light-induced resonance control in semiconductor CdZnTe

Tal Schwartz, Yaniv Ganor, Tal Carmon +4 more

Summary form only given. We demonstrate the formation of (1 + 1)D and of (2 + 1)D solitons in the photorefractive semiconductor CdZnTe:V, and show how to optically control the resonance intensity, which facilitates microseconds formation times at very low optical power. CdZnTe:V has a similar intensity-resonant mechanism as InP:Fe, with an important difference: the electrons and the holes exchange roles. Electrons are optically excited by a 1.3 /spl mu/m (or shorter) wavelength, whereas holes are thermally excited. However, the holes can also be excited optically, by a /spl sim/1.5 /spl mu/m wavelength beam. Here, we take advantage of this property to increase (and control) the hole excitation rate considerably by uniformly illuminating the crystal with a 1.48 /spl mu/m wavelength beam (the "background beam"). This background beam sets the resonance intensity to much higher values than temperature-driven resonance, thereby shortening their formation time to 10 microsecond with soliton intensity of /spl sim/20 W/cm/sup 2/ and background intensity of /spl sim/1 W/cm/sup 2/.

Conference on Lasers and Electro-Optics•Jun 25, 2003•1 citation
Induced absorption was observed in an InP:Fe crystal under nanosecond pulse illumination at 1.06- mu m wavelength. The maximum induced absorption was 0.05 cm/sup -1/ when probed at a 1.06- mu m wavelength and 0.30 cm/sup -1/ when probed at a 1.30- mu m wavelength. The kinetics are studied together with the photocurrent giving the recombination times of holes (100 ns) at room temperature and an estimate for that of electrons (0.5 ns). The induced absorption is attributed to a population redistribution of the different iron impurity states. Computer simulations are able to explain all the features found in the experiments and give values for the photoionization cross sections, in particular for the unknown cross section Fe/sup 2+*/ to Fe/sup 3+/+e/sup -/.>
For understanding and optimization of the photo refractive gain it is important to know the basic parameters of photo-ionization and recombination processes. In the nanosecond regime the pulse energies required for maximum coupling gain in semiconductors easily reach the limit for saturation of the deep centers. especially if one of the recombination times is larger than the pulse duration. In that case, induced absorption (or bleaching) will appear due to a redistribution of the population of the different levels of the deep center and counterbalance photorefractive amplification. The present simultaneous study of the kinetics of the induced absorption and the photocurrent in an InP:Fe sample reveals a number of interesting parameters like electron and hole recombination times, ionization cross sections and Fe2+/Fe3+ concentrations.
Iron-ion concentrations have been determined from measurements of the photoinduced-grating erasure times. We checked the accuracy of this method by performing two-wave mixing experiments at λ = 1.32 μm without an applied field. After verifying the fit of the extended single-defect model with indirect transitions and the two-wave mixing gain data at λ = 1.06 μm, we conclude that the indirect transitions involving the excited state of Fe2+ can induce a reduction of the photorefractive effect in InP:Fe when the dominant photocarriers are holes at room temperature.
We have observed two-beam coupling gain (0.273 cm−1) that exceeds absorption (0.145 cm−1) in InP:Fe without applying an external field at λ=1.32 μm. Measurements of the gain coefficient as a function of grating spacing fit the photorefractive theory for simultaneous electron-hole transport, with the effective density of traps NE = (3.86 ± 1.1)NE=(3.86±1.1)× 1015 cm−3 and ξ, the factor that accounts for competition between electrons and holes, equaling −0.729±0.026. Absorption measurements, combined with the photoionization cross sections of electrons and holes, confirm these results. The agreement between theory and experiment suggests how to choose impurity concentrations that optimize net gain.
We show that even if there is no direct hole–electron competition in InP:Fe the gain is lower than expected. We attribute this reduction of the gain to a thermally induced hole–electron competition that involves the excited state of Fe2+ (5T2). We present a new model for the photorefractive effect in InP:Fe, which we use to interpret our beam-coupling results. Some material parameters of the InP:Fe sample and particularly of the excited state are deduced. The same energy-transfer measurements conducted in GaAs give us the ratio of hole and electron photoionization cross sections.
Summary form only given. We demonstrate the formation of (1 + 1)D and of (2 + 1)D solitons in the photorefractive semiconductor CdZnTe:V, and show how to optically control the resonance intensity, which facilitates microseconds formation times at very low optical power. CdZnTe:V has a similar intensity-resonant mechanism as InP:Fe, with an important difference: the electrons and the holes exchange roles. Electrons are optically excited by a 1.3 /spl mu/m (or shorter) wavelength, whereas holes are thermally excited. However, the holes can also be excited optically, by a /spl sim/1.5 /spl mu/m wavelength beam. Here, we take advantage of this property to increase (and control) the hole excitation rate considerably by uniformly illuminating the crystal with a 1.48 /spl mu/m wavelength beam (the "background beam"). This background beam sets the resonance intensity to much higher values than temperature-driven resonance, thereby shortening their formation time to 10 microsecond with soliton intensity of /spl sim/20 W/cm/sup 2/ and background intensity of /spl sim/1 W/cm/sup 2/.