48 research outputs found
Noise and deviation effects in a bichromatic Raman white light cavity
We analyze the effects of noise and parameter deviations in a bichromatic
Raman type white light cavity, with potential applications in precision
measurements such as gravitational wave detection. The results show that the
dispersion variation induced by parameter deviation can be controlled within
. The laser phase noise decreases the dispersion magnitude while the
amplitude noise increases it. Although we can always adjust the parameters to
satisfy the white light condition, both noises make the cavity transmission
curve uneven.Comment: 5 pages, 3 figure
Ultrafast Image Retrieval from a Holographic Memory Disc for High-Speed Operation of a Shift, Scale, and Rotation Invariant Target Recognition System
The hybrid opto-electronic correlator (HOC) architecture has been shown to be
able to detect matches in a shift, scale, and rotation invariant (SSRI) manner
by incorporating a polar Mellin transform (PMT) pre-processing step. Here we
demonstrate the design and use of a thick holographic memory disc (HMD) for
high-speed SSRI correlation employing an HOC. The HMD was written to have 1,320
stored images, including both unprocessed images and their PMTs. We further
propose and demonstrate a novel approach whereby the HOC inputs are spatially
shifted to produce correlation signals without requiring stabilization of
optical phases, yielding results that are in good agreement with the theory.
Use of this approach vastly simplifies the design and operation of the HOC,
while improving its stability significantly. Finally, a real-time
opto-electronic PMT pre-processor utilizing an FPGA is proposed and prototyped,
allowing for the automatic conversion of images into their PMTs without
additional processing delay.Comment: Conferenc
High-speed Opto-electronic Pre-processing of Polar Mellin Transform for Shift, Scale and Rotation Invariant Image Recognition at Record-Breaking Speeds
Space situational awareness demands efficient monitoring of terrestrial sites
and celestial bodies, necessitating advanced target recognition systems.
Current target recognition systems exhibit limited operational speed due to
challenges in handling substantial image data. While machine learning has
improved this scenario, highresolution images remain a concern. Optical
correlators, relying on analog processes, provide a potential alternative but
are hindered by material limitations. Recent advancements in hybrid
opto-electronic correlators (HOC) have addressed such limitations, additionally
achieving shift, scale, and rotation invariant (SSRI) target recognition
through use of the polar Mellin transform (PMT). However, there are currently
no techniques for obtaining the PMT at speeds fast enough to take advantage of
the inherent speed of the HOC. To that end, we demonstrate an optoelectronic
PMT pre-processor that can operate at record-breaking millisecond frame rates
using commercially available components for use in an automated SSRI HOC image
recognition system for space situational awareness.Comment: Conferenc