GaAs/AlAs Multilayer Cavity with InAs Quantum Dots Embedded in Strain-Relaxed Barriers for Planar-Type Optical Kerr Gate Switches

A GaAs/AlAs multilayer cavity containing self-assembled InAs quantum dots (QDs) embedded in strain-relaxed In0.35Ga0.65As barriers has been studied for planar-type optical Kerr gate switches. The multilayer cavity structure with smooth GaAs/AlAs interfaces was successfully grown on a (001) GaAs substrate by molecular beam epitaxy despite the lattice strain relaxation induced in the half-wavelength (λ/2) cavity layer. Time-resolved optical measurements at the cavity mode (λ= 1.46 µm) were performed by a pump–probe method at room temperature. Although only two layers of the InAs QDs were inserted into the λ/2 cavity layer, a large transmission change caused by the absorption saturation in the resonant QDs was clearly observed. The temporal profile was dominated by a fast (~16 ps) decay component, which comes from carrier relaxation into the nonradiative centers arising from the lattice strain relaxation. We have also shown that an ultrafast response time (<1 ps) of the strongly enhanced optical Kerr signal is determined by the photon lifetime in the multilayer cavity.

[1]  Shu Namiki,et al.  All-optical demultiplexing of 160–10Gbit∕s signals with Mach-Zehnder interferometric switch utilizing intersubband transition in InGaAs∕AlAs∕AlAsSb quantum well , 2007 .

[2]  Takahiro Kitada,et al.  Asymmetric temporal profile of optical Kerr signal from GaAs/AlAs multilayer with λ/2 phase shift layer , 2009 .

[3]  Takahiro Kitada,et al.  A GaAs/AlAs Multilayer Cavity with Self-Assembled InAs Quantum Dots Embedded in Strain-Relaxed Barriers for Ultrafast All-Optical Switching Applications , 2008 .

[4]  J.J.G.M. van der Tol,et al.  All-optical switching due to state filling in quantum dots , 2004, cond-mat/0410440.

[5]  Masaya Notomi,et al.  All-optical switches on a silicon chip realized using photonic crystal nanocavities , 2005 .

[6]  Takahiro Kitada,et al.  Optical Kerr signals of GaAs/AlAs multilayer cavities for a short pulse , 2009 .

[7]  T. Isu,et al.  Enhanced Two-Photon Absorption in a GaAs/AlAs Multilayer Cavity , 2008 .

[8]  K. Asakawa,et al.  Ultra-fast photonic crystal/quantum dot all-optical switch for future photonic networks , 2004, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[9]  T. Isu,et al.  Fast carrier relaxation of self-assembled InAs quantum dots embedded in strain-relaxed In0.35Ga0.65As barriers for ultrafast nonlinear optical switching applications , 2009 .

[10]  Takahiro Kitada,et al.  Marked Enhancement of Optical Kerr Signal in Proportion to Fourth Power of Quality Factor of a GaAs/AlAs Multilayer Cavity , 2009 .

[11]  Tomoya Takahashi,et al.  GaAs/AlAs coupled multilayer cavity structures for terahertz emission devices , 2009 .

[12]  Mark Hopkinson,et al.  Vertical-geometry all-optical switches based on InAs/GaAs quantum dots in a cavity , 2009 .

[13]  Y. Kawamura,et al.  Ultrafast 1.55 μm all‐optical switching using low‐temperature‐grown multiple quantum wells , 1996 .

[14]  Tomoya Takahashi,et al.  Enhanced Optical Kerr Signal of GaAs/AlAs Multilayer Cavity with InAs Quantum Dots Embedded in Strain-Relaxed Barriers , 2009 .

[15]  Hiroshi Ishikawa,et al.  Nonlinear optical phase shift in InAs quantum dots measured by a unique two-color pump/probe ellipsometric polarization analysis , 2004 .