All‐optical logic elements containing nonlinear material

For a highly information-oriented society, further enhancement of the capacity and speed of communications and information systems is necessary. For this purpose, all-optical logic elements are expected as a promising solution. In this paper, structures of new all-optical logic elements using a nonlinear medium with its index of refraction varying with the optical intensity are proposed and their properties are analyzed. Most of the all-optical logic elements based on nonlinear materials proposed to date either make use of more than two wavelengths or require a specific phase condition (such as 0° or 180°) for combined lightwaves with identical wavelengths. It is extremely difficult to fix the phase difference between the two lightwaves to be combined. This is a significant problem in practical fabrication. In this paper, all-optical logic elements are proposed in which only one wavelength is used and no specific phase relationship is required. For the numerical analysis, the FD-BPM (Finite Difference Beam Propagation Method) based on the Pade) (1, 1) approximation is used. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(9): 1–12, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10048

[1]  Chan Ki Kim,et al.  All-optical logic functions in a bent nonlinear Y-junction waveguide , 1997 .

[2]  G. R. Hadley,et al.  Wide-angle beam propagation using Pade approximant operators. , 1992, Optics letters.

[3]  Juerg Leuthold,et al.  All-optical Mach-Zehnder interferometer wavelength converters and switches with integrated data- and control-signal separation scheme , 1999 .

[4]  Youfa Wang,et al.  All-fiber logical devices based on the nonlinear directional coupler , 1999 .

[5]  P. Pierleoni,et al.  Coupled-soliton photonic logic gates: practical design procedures , 1995 .

[6]  Youngchul Chung,et al.  An assessment of finite difference beam propagation method , 1990 .

[7]  Hiroyoshi Yajima,et al.  Dielectric thin‐film optical branching waveguide , 1973 .

[8]  Mario Bertolotti,et al.  All-optical nor gate based on the interaction between cosine-shaped input beams of orthogonal polarization , 1999 .

[9]  Yaron Silberberg,et al.  All-optical switching in waveguide X junctions , 1990 .

[10]  Michel E. Marhic,et al.  All-optical logic gates based on cross-phase modulation in a nonlinear fiber interferometer , 1991, Nonlinear Guided-Wave Phenomena.

[11]  Reduction of the degree of polarization of a laser diode with a fiber Lyot depolarizer , 1999, IEEE Photonics Technology Letters.

[12]  Y. Silberberg,et al.  All-optical phase- and power-controlled switching in nonlinear waveguide junctions. , 1988, Optics letters.

[13]  George I. Stegeman,et al.  All‐optical switching in nonlinear X junctions , 1989 .