Localized Kerr-type nonlinearities in GaAs/AlGaAs multiple quantum well structures at 1.55 μm

Hamilton, C.J.; Marsh, J.H.; Hutchings, D. C.; Aitchison, J. S.; Kennedy, G. T.; Sibbett, W.

doi:10.1063/1.116428

Cited by 30 publications

(18 citation statements)

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“…Solutions of a structure containing guiding nonlinear dielectric films are much more complex and involves Jacobi elliptic functions. Such waveguide structures are particularly relevant for multiple quantum well lasers and other non-linear multi-branch systems (Hamiltoin et al 1996;Wu et al 2001). Only few works (Wu 2004;Wu and Chen 2005) are known to analyze this problem successfully.…”

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confidence: 98%

Analysis of arbitrary index profile planar optical waveguides and multilayer nonlinear structures: a simple finite difference algorithm

Chaudhuri

Roy

2007

Opt Quant Electron

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we present here a simple numerical method to obtain the mode effective indices as well as field distributions of modes of any arbitrary profile planar optical waveguide. The method is based on the solutions of scalar and semivectorial Helmoltz's equation by finite difference algorithm and devised with a field convergence technique. This approach is quite general and can be applied straightforwardly to calculate the guided as well as quasior leaky modes of any arbitrary planar structure without the need to solve any eigenvalue equation or any complex matrix formalism. Besides providing the ease of application, the algorithm is particularly useful for waveguides with any graded index profile or with irregular multilayered structure and multilayered waveguides with a localised arbitrary nonlinear film. The performance of our method is verified against typical problems with analytical solutions or having results known otherwise, and is shown to yield results with good accuracy.

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confidence: 98%

Analysis of arbitrary index profile planar optical waveguides and multilayer nonlinear structures: a simple finite difference algorithm

Chaudhuri

Roy

2007

Opt Quant Electron

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“…In comparison to previous work on intermixing MQW waveguides [13], the observed suppression of in the superlattice is up to 11% larger. Furthermore, the present intermixing technique and dosage is less traumatic to the underlying crystalline structure, i.e., it is not fully intermixed with commensurate lower optical losses, and provides a higher spatial resolution.…”

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confidence: 81%

“…The PL peak for the as-grown material places the half-band-gap energy within the 1550-nm telecommunications band. Intermixing shifted the PL peak by 68 nm, which is larger than the 40-nm shifts achieved with a conventional MQW [13]. Strip-loaded waveguides, each 3.0 m wide and 1.0 m deep were fabricated using reactive ion etching for both as-grown and intermixed samples.…”

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confidence: 99%

Controlling Third-Order Nonlinearities by Ion-Implantation Quantum-Well Intermixing

Wagner

Holmes

Younis

et al. 2009

IEEE Photon. Technol. Lett.

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Abstract-The optical Kerr effect was measured by observing self-phase modulation in GaAs-AlGaAs superlattice-core waveguides modified by ion-implantation quantum-well intermixing. The band-gap energy was shifted by 68 nm for an implantation dose of 0 5 10 13 cm 2 and annealing temperature of 775 C. The Kerr effect was suppressed by up to 71% in the transverse-electric polarization after intermixing. A reduced polarization dependence of the self-phase modulation was observed after intermixing.Index Terms-Nonlinear optics, optical Kerr effect, quantumwell intermixing (QWI), semiconductor superlattice. COMPOUND semiconductors have led the way towards monolithically integrated all-optical signal processing devices. Mature fabrication technologies have allowed the development of low-loss waveguides and advanced structures such as Bragg reflection waveguides [1], passive mode converters [2], and cascaded microring resonators [3]. AlGaAs is of particular interest since the optical Kerr effect, a third-order nonlinearity, has been shown to be 500 times stronger than in silica [4]. These nonlinearities are nonresonant and do not rely on free-carrier plasma dispersion effects since the operating wavelengths are typically below the half-band-gap energy. This has opened the possibility of all-optical switching devices such as nonlinear directional couplers (NLDCs) [5] and nonlinear Mach-Zehnder interferometers (NLMZIs) [6] with ultrafast response times necessary for ultrahigh-speed communications systems and signal processing. Multiple quantum-well (MQW) structures based on AlGaAs permit greater flexibility to tailor the band-gap energy to suit the optical properties required for particular applications. Furthermore, the band-gap energy of MQWs can be modified after wafer growth by quantum-well intermixing (QWI) techniques [7]. This cost-effective approach allows selective control , which is a requirement for devices such as QPM gratings. Deep-well semiconductor superlattices have attracted attention as the greater fill-factor and large band discontinuity in comparison to conventional quantum-well structures potentially provides a larger modification to nonresonant optical properties such as the refractive index and nonlinear optical susceptibilities in the transparency window for the complete structure. Thus, shorter and more efficient devices that require less power to operate are possible. In this letter, we demonstrate large modifications of the optical Kerr effect in GaAs-AlGaAs superlattice-core waveguides induced by ionimplantation QWI at wavelengths near the half-band-gap. We have previously reported on the large polarization dependence of the Kerr coefficient in GaAs-AlAs superlattice waveguides [12]. However, measurements indicated the presence of parasitic two-photon absorption (TPA) resonances due to the reduced barrier resulting in asymmetric quantum wells (ASQW) found on either side of the superlattice waveguide core. In the present study, we modified the waveguide structure with several improvements. The new ...

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“…Associated with changes in the absorption coefficient are changes in the refractive index through the Kramers-Kronig relations [6,7] with applications for waveguides and bragg gratings. In addition to these variations in the linear optical properties, it has also been established that quantum well disordering can give rise to a modulation in second-and third-order nonlinear optical coefficients [8][9][10]. This effect can potentially be exploited as a novel quasi-phase-matching technique for wavelength conversion and other second-order nonlinear optical applications.…”

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confidence: 96%

Electronic bandstructure of disordered superlattices

Hutchings

1999

Superlattices and Microstructures

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Localized Kerr-type nonlinearities in GaAs/AlGaAs multiple quantum well structures at 1.55 μm

Cited by 30 publications

References 0 publications

Analysis of arbitrary index profile planar optical waveguides and multilayer nonlinear structures: a simple finite difference algorithm

Analysis of arbitrary index profile planar optical waveguides and multilayer nonlinear structures: a simple finite difference algorithm

Controlling Third-Order Nonlinearities by Ion-Implantation Quantum-Well Intermixing

Electronic bandstructure of disordered superlattices

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