Photonic security system using spatial codes and remote coded coherent optical communications

Nabeel A. Riza; Mostofa M. K. Howlader; Nicholas Madamopoulos

doi:10.1117/1.600853

1 September 1996 Photonic security system using spatial codes and remote coded coherent optical communications

Nabeel A. Riza, Mostofa M. K. Howlader, Nicholas Madamopoulos

Optical Engineering, Vol. 35, Issue 9, (September 1996). https://doi.org/10.1117/1.600853

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 matchmismatch 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.

Citation Download Citation

Nabeel A. Riza, Mostofa M. K. Howlader, and Nicholas Madamopoulos "Photonic security system using spatial codes and remote coded coherent optical communications," Optical Engineering 35(9), (1 September 1996). https://doi.org/10.1117/1.600853

Published: 1 September 1996

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available