Photonic Security System Using Spatial Codes And Remote Coded Coherent Optical Communications

    Authors

    N. A. Riza; M. M. K. Howlader;N. Madamopoulos

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Opt. Eng.

    Keywords

    optical security; optical code; identification card; security system; photonic encoder; coherent optical communications; keycodes; Optics

    Abstract

    A novel photonic security system is described using 2-D spatial codes based on both optical phase and amplitude information. This security system consists of an optical interferometric encoding subsystem that rapidly reads and encodes the 2-D complex-valued spatial code, forming a wideband frequency modulated optical beam and a colinear optical reference beam. After appropriate coherence coding of this beam pair, the light is launched into a low probability of intercept communication channel such as an optical fiber or a narrow beamwidth free-space optical link. At the remote code receiving and data processing site, the received light beam pair is first coherently decoded. Then, a high speed photodetector via optical heterodyne detection generates an encoded wideband radio frequency signal that contains the original 2-D code. Decoding is implemented in parallel via two independent systems. One decoder uses a Fourier transforming lens to reconstruct an electronic image interferogram of the complex-valued user code. This image interferogram is sent to a high speed electronic image processor for verification purposes. The other decoder is a high speed coherent acousto-optic time integrating correlator that optically determines match-mismatch between the received encoded signal and the code signal generated by the electronic database. Improved security to the overall communication network is added by using various keycodes such as a time varying keycode that determines the exact spatial beam scanning sequence required for both proper encoding and decoding of the 2-D code information. This paper describes preliminary experiments using a simple 1-D amplitude modulated spatial code. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

    Journal Title

    Optical Engineering

    Volume

    35

    Issue/Number

    9

    Publication Date

    1-1-1996

    Document Type

    Article

    Language

    English

    First Page

    2487

    Last Page

    2498

    WOS Identifier

    WOS:A1996VG76400009

    ISSN

    0091-3286

    Share

    COinS