Transverse Nonlinear Optics

TONICS - 7118

Work Area: Novel Concepts and New Materials for Optical Devices / All-Optical Computing

Keywords nonlinear optics, lasers, pattern, recognition, parallel processing, optical information processing

Start Date: 1 June 92 / Duration: 24 months / Status: running

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Abstract TONICS explores the formation of spatial structures in nonlinear optical systems such as lasers, passive resonators or in mirrorless light-matter interaction, and develops methods in which this structure formation can be utilised in all-optical parallel information processing. Recognition of small numbers of patterns by lasers has been demonstrated. Femto-Joule switching between laser states has been shown.

Aims

In the recent past a new field in optics has developed, the results of which could lead to new methods in parallel optical information processing. The TONICS project aims to gain an overview of the structure formation phenomena occuring in various configurations of nonlinear optical systems, to single out the phenomena with the greatest potential usefulness, and to carry out experiments demonstrating the possibility of applications.

Approach and Methods

Theoretical analysis have been used to investigate the spatial structure formation in lasers and in Kerr-media that contain counterpropagating fields with and without resonators. To verify the theoretical results simple lasers have been utilised, among them CO2 lasers as model systems for surface emitting semiconductor lasers, and liquid crystals for Kerr media.

Progress and Results

The generic structure formation of lasers and the interaction creation / annihilation / self-interaction (vortices) which can form pixels has been clarified. Switching between positive and negative vortex emission has been demonstrated with low energies, which can be in the one Femto-Joule range.

CO2 lasers have permitted multi-element modelling the behaviour of semiconductor laser arrays. Connections with quantum information techniques have been made theoretically.

Potential

The energies for switching between two laser states are now found to be similar to these of MOS transistors. The availability of surface emitting semiconductor lasers with well controlled properties should permit small optical switching and optical recognition elements.

Latest Publications

• Lapucci A, Cangioli G Triple slap radio-frequency discharged CO2-laser Appl. Phys. Lett. 62 (1) 7 (1993)
• Weiss C O, Telle H R, Staliunas K, Brambilla M Restless optical vortex Physical Review A 47 (3) R1616 (1993)
• Lugiato L A, Gatti A Spatial structure of a squeezed vacuum Phys. Rev. Lett., to appear
• McDonald G S, Firth W J Switching Dynamics of Spatial Solitary Wave Pixels Phys. Rev., to appear
• Smith C P, Dihardia Y, Weiss C O, Lugiato L A, Prati F, Vanotti P Low energy switching of laser doughnut modes and pattern recognition Opt. Comm., in press

Information Dissemination Activies

• Publications in major physics journals
• presentation at major optics conferences
• organisation of a public workshop (Como, June 1993).

Coordinator

Physikalisch-Technische Bundesanstalt - D
Bundesallee 100
D - 3300 BRAUNSCHWEIG

Partners

Association pour le développement des études non-linéaires (ADEN) - F
Istituto Nazionale di Ottica - I
ALENIA - I
INFM - I
University of Strathclyde - UK
British Telecommunications plc - UK

CONTACT POINT

Prof. C.O. Weiss
tel +49/531-592-4400
fax +49/531-592-9292

TONICS - 7118, August 1994

please address enquiries to the ESPRIT Information Desk

html version of synopsis by Nick Cook