Band-Gap—Resonant Nonlinear Refraction in III-V Semiconductors

Miller, D. A. B.; Seaton, C. T.; Prise, M. E.; Smith, S. D.

doi:10.1103/physrevlett.47.197

Cited by 273 publications

(40 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although (5) is only an approximation in the case of semiconductors, it predicts correctly the asymptotic behavior of (3).…”

mentioning

confidence: 71%

“…These attractive properties are obtained using the large excitonic-resonant nonlinear refractive index Sn,, of GaAs MQWs at room temperature [3], which involves the photoexcitation of electron-hole pairs, initially created in the low-energy tail of the excitonic and band-to-band optical transitions (Urbach's tail), and subsequently thermalized in higherenergy states through interaction with the lattice vibrations. In the course of our studies of such bistable microcavities, it was found that, due to the short nonlinear medium length (typically 100 QWs with a 20 nm periodicity), optical bistability could only be observed in the highest finesse cavities [4], which suggested that the available nonlinear phase shift was limited by some saturation mechanism.In the nonsaturating regime, Sn,, is simply proportional to the intensity I , and it is well known that n, defined as &,,(I) = n,l is proportional to the linear absorption coefficient a0 [5]. It is thus possible to define a figure of merit nJao which gives information about the nonlinear efficiency of the material.…”

mentioning

confidence: 98%

“…If one ignores the r ( N ) dependence, (4) and (5) give the following relation between the carrier density and the intensity: with I, = hoN,/a,z. Although (5) is only an approximation in the case of semiconductors, it predicts correctly the asymptotic behavior of (3).…”

mentioning

confidence: 98%

See 2 more Smart Citations

Saturation of Band‐Tail Absorption in Multiple Quantum Wells and Its Link with the Nonlinear Index Saturation

Raj¹,

Sfez²,

Pellat³

et al. 1992

Physica Status Solidi (b)

View full text Add to dashboard Cite

A pump and probe measurement of the nonlinear transmission reveals that the origin of the saturating behaviour of the nonlinear index 6 1 1 ,~ observed in the band tail of GaAs/GaAIAs multiple quantum wells is due to the saturation of the photoexcited carrier density.It has been discovered recently that the dispersive nonlinearity of MQW exhibits a strong saturating behavior [I], which constitutes a serious limitation in the design of optical bistable etalons. Indeed, epitaxial methods allow the fabrication of nonlinear interferometric structures incorporating distributed Bragg reflectors and GaAs multiple quantum well (MQW) nonlinear media in a single crystal [2]. This results in very compact nonlinear microcavities, with typically 5 pm overall thickness. Optical bistability is observed in these structures at mW optical power, with a high contrast in the reflection mode [l]. These attractive properties are obtained using the large excitonic-resonant nonlinear refractive index Sn,, of GaAs MQWs at room temperature [3], which involves the photoexcitation of electron-hole pairs, initially created in the low-energy tail of the excitonic and band-to-band optical transitions (Urbach's tail), and subsequently thermalized in higherenergy states through interaction with the lattice vibrations. In the course of our studies of such bistable microcavities, it was found that, due to the short nonlinear medium length (typically 100 QWs with a 20 nm periodicity), optical bistability could only be observed in the highest finesse cavities [4], which suggested that the available nonlinear phase shift was limited by some saturation mechanism.In the nonsaturating regime, Sn,, is simply proportional to the intensity I , and it is well known that n, defined as &,,(I) = n,l is proportional to the linear absorption coefficient a0 [5]. It is thus possible to define a figure of merit nJao which gives information about the nonlinear efficiency of the material. When the nonlinearity saturates, it is no longer possible to rely on such a model. It is therefore of great interest to investigate how the saturation parameters vary with the absorption.Recently a direct measurement of the nonlinear index of semiconductors embedded in a Fabry-Perot cavity, showed a clear saturation behavior of the nonlinear index change Sn,, as a function of intracavity power P [6]. The experimental data were found to fit very well with a saturation law PIPS Srz,,(P) = Sn, -~.

show abstract

“…Although (5) is only an approximation in the case of semiconductors, it predicts correctly the asymptotic behavior of (3).…”

mentioning

confidence: 71%

mentioning

confidence: 98%

See 1 more Smart Citation

Saturation of Band‐Tail Absorption in Multiple Quantum Wells and Its Link with the Nonlinear Index Saturation

Raj¹,

Sfez²,

Pellat³

et al. 1992

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…This argument had remained until the emergence of semiconductor QW technology in the 1980's and the discovery of optical bistability [43][44][45]. Significantly improved optical nonlinearity was demonstrated by utilizing the quantum confined Stark effect (QCSE) in semiconductors [46], which resulted in a series of successful demonstrations of optical logic devices [47] and large scale photonic integration [48]. In the meantime, the idea of using optical resonators to enhance the switching performance was proposed [49] and experimentally demonstrated [50].…”

Section: Fundamental Limitationsmentioning

confidence: 99%

Photonic switching devices based on semiconductor nano-structures

Jin¹,

Wada²

2014

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Abstract:Focusing and guiding light into semiconductor nanostructures can deliver revolutionary concepts for photonic devices, which offer a practical pathway towards next-generation power-efficient optical networks. In this review, we consider the prospects for photonic switches using semiconductor quantum dots (QDs) and photonic cavities which possess unique properties based on their low dimensionality. The optical nonlinearity of such photonic switches is theoretically analysed by introducing the concept of a field enhancement factor. This approach reveals drastic improvement in both power-density and speed, which is able to overcome the limitations that have beset conventional photonic switches for decades. In addition, the overall power consumption is reduced due to the atom-like nature of QDs as well as the nano-scale footprint of photonic cavities. Based on this theoretical perspective, the current state-of-the-art of QD/cavity switches is reviewed in terms of various optical nonlinearity phenomena which have been utilized to demonstrate photonic switching. Emerging techniques, enabled by cavity nonlinear effects such as wavelength tuning, Purcell-factor tuning and plasmonic effects are also discussed.

show abstract

“…Since xi:)(w) dominates a t resonance w = E, ( Then we can calculate the coefficient n2 of the light intensity dependence of the refractive index n. The values of n2 obtained from formulae (14) and (19) a t the temperature T = 77 K are compared with the experimental data [6] in Table 1. We see that the calculation in case 2 (formula (19), scattering by acoustic phonons) gives a better agreement with the experiment at resonance o rr E , == 1835 cm-l. For the non-resonant value of OJ the approximate simple formula (19) is not valid, and we do not expect its agreement with the experiment.…”

Section: Casementioning

confidence: 99%