RESUMEN
The hybrid opto-electronic correlator (HOC) uses a combination of optics and electronics to perform target recognition. Achieving a stable output from this architecture has previously presented a significant challenge due to a high sensitivity to optical phase variations, limiting the real-world feasibility of the device. Here we present a modification to the architecture that essentially eliminates the dependence on optical phases, and demonstrate verification of the proposed approach. Experimental results are shown to agree with the theory and simulations, for scale, rotation and shift invariant image recognition. This approach represents a major innovation in making the HOC viable for real-world applications.
RESUMEN
The hybrid optoelectronic correlator (HOC) combines optical and electronic signal processing to achieve the same functionality as traditional optical correlators but without the need for dynamic materials. Here we propose and demonstrate the integration of a PQ:PMMA holographic memory device (HMD) into the HOC as a high-speed all-optical database for reference images. Using a PQ:PMMA HMD for one of the inputs eliminates one of the key speed limitations in the HOC. The observed correlation signal agrees with simulations but highlights the need for high quality holographic substrates in this application.
RESUMEN
Phenantrenequinone doped poly(methyl-methacrylate) (PQ:PMMA) is a holographic substrate that can be used for angle or wavelength multiplexed Bragg gratings. However, efficient writings can be done only using a high-power, long-coherence volume laser over a limited wavelength range. This constraint makes it difficult to write gratings that would diffract several different read wavelengths into a single direction. We describe the rules for writing such gratings, taking into account the differences in the mean index seen by the write and read wavelengths. We further demonstrate the use of such a transmission hologram for wavelength-division multiplexing in a free-space optical communication system.
RESUMEN
We present experimental results of photonic crystal ring resonators (PhCRRs) fabricated on the CMOS-compatible, silicon-on-insulator platform via 193-nm deep-UV lithography. Our dispersion-engineering design approach is compared to experimental results, showing very good agreement between theory and measurements. Specifically, we report a mean photonic band-edge wavelength of 1546.2 ± 5.8 nm, a 0.2% variation from our targeted band-edge wavelength of 1550 nm. Methods for the direct calculation of the experimental, discrete dispersion relation and extraction of intrinsic quality factors for a highly-dispersive resonator are discussed. A maximum intrinsic quality factor of ≈83,800 is reported, substantiating our design method and indicating that high-throughput optical lithography is a viable candidate for PhCRR fabrication. Finally, through comparison of the mean intrinsic quality and slowdown factors of the PhCRRs and standard ring resonators, we present evidence of an increase in light-matter interaction strength with simultaneous preservation of microcavity lifetimes.
