Ultrafast all-optical switching with low saturation energy via intersubband transitions in GaN/AlN quantum-well waveguides.

A fiber-optic pump-probe setup is used to demonstrate all-optical switching based on intersubband cross-absorption modulation in GaN/AlN quantum-well waveguides, with record low values of the required control pulse energy. In particular, a signal modulation depth of 10 dB is obtained with control pulse energies as small as 38 pJ. Such low power requirements for this class of materials are mainly ascribed to an optimized design of the waveguide structure. At the same time, the intersubband absorption fully recovers from the control-pulse-induced saturation on a picosecond time scale, so that these nonlinear waveguide devices are suitable for all-optical switching at bit rates of several hundred Gb/s.

[1]  R. Soref,et al.  Nonlinear all-optical GaN∕AlGaN multi-quantum-well devices for 100Gb∕s applications at λ=1.55μm , 2005 .

[2]  Francois H. Julien,et al.  Electron confinement in strongly coupled GaN /AlN quantum wells , 2006 .

[3]  Anirban Bhattacharyya,et al.  Intersubband absorption in AlN∕GaN∕AlGaN coupled quantum wells , 2007 .

[4]  Anirban Bhattacharyya,et al.  Nonlinear optical waveguides based on near-infrared intersubband transitions in GaN/AlN quantum wells. , 2007, Optics express.

[5]  N. Suzuki,et al.  All-optical switch utilizing intersubband transition in GaN quantum wells , 2006, IEEE Journal of Quantum Electronics.

[6]  F. Julien,et al.  Systematic experimental and theoretical investigation of intersubband absorption in GaN/AlN quantum wells , 2006 .

[7]  Claire F. Gmachl,et al.  Intersubband absorption at λ∼1.55 μm in well- and modulation-doped GaN/AlGaN multiple quantum wells with superlattice barriers , 2000 .

[8]  Roberto Paiella,et al.  Intersubband all-optical switching based on Coulomb-induced optical nonlinearities in GaN/AlGaN coupled quantum wells , 2006 .

[9]  Roberto Paiella,et al.  Investigation of the design parameters of AlN/GaN multiple quantum wells grown by molecular beam epitaxy for intersubband absorption , 2005 .

[10]  Claire F. Gmachl,et al.  Resonant optical nonlinearities from intersubband transitions in GaN/AlN quantum wells , 2003 .

[11]  Kei Kaneko,et al.  Near-infrared intersubband absorption in GaN/AlN quantum wells grown by molecular beam epitaxy , 2002 .

[12]  Raffaele Colombelli,et al.  Room-temperature intersubband emission of GaN/AlN quantum wells at /spl lambda/=2.3 /spl mu/m , 2006 .

[13]  Esther Baumann,et al.  Electrically adjustable intersubband absorption of a GaN∕AlN superlattice grown on a transistorlike structure , 2006 .

[14]  J. Hamazaki,et al.  Ultrafast intersubband relaxation and nonlinear susceptibility at 1.55 μm in GaN/AlN multiple-quantum wells , 2004 .

[15]  T Hasama,et al.  Low-saturation-energy-driven ultrafast all-optical switching operation in (CdS/ZnSe)/BeTe intersubband transition. , 2007, Optics express.

[16]  A. Neogi,et al.  Intersubband absorption saturation in InGaAs-AlAsSb quantum wells , 2002 .

[17]  Rongqing Hui,et al.  GaN-based waveguide devices for long-wavelength optical communications , 2003 .

[18]  Lester F. Eastman,et al.  GaN/AlN-based quantum-well infrared photodetector for 1.55 μm , 2003 .