1 October 2005 Broadband polarization interferometric time-integrating acousto-optic correlator for random noise radar
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Optical Engineering, 44(10), 108202 (2005). doi:10.1117/1.2084807
Abstract
We describe a time-integrating acousto-optic correlator (TIAOC) developed for imaging and target detection using a wideband random-noise radar system. This novel polarization interferometric in-line TIAOC uses an intensity-modulated laser diode for the random noise reference and a polarization-switching, self-collimating acoustic shear-mode gallium phosphide (GaP) acousto-optic device for traveling-wave modulation of the radar returns. The time-integrated correlation output is detected on a 1-D charge-coupled device (CCD) detector array and calibrated and demodulated in real time to produce the complex radar range profile. The complex radar reflectivity is measured in more than 150 radar range bins in parallel on the 3000 pixels of the CCD, improving target acquisition speeds and sensitivities by 150 over previous serial analog correlator approaches. The polarization interferometric detection of the correlation using the undiffracted light as the reference allows us to use the full acousto-optic device (AOD) bandwidth as the system bandwidth. Also, the experimental result shows the fully complex random-noise signal correlation and coherent demodulation without an explicit carrier, demonstrating that optically processed random-noise radars do not need a stable local oscillator.
Sangtaek Kim, Kelvin H. Wagner, Ram Mohan Narayanan, Wei Zhou, "Broadband polarization interferometric time-integrating acousto-optic correlator for random noise radar," Optical Engineering 44(10), 108202 (1 October 2005). http://dx.doi.org/10.1117/1.2084807
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KEYWORDS
Charge-coupled devices

Radar

Semiconductor lasers

Optical correlators

Acousto-optics

Modulation

Polarization

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