We discuss the use of photonic crystal slab to accomplish a number of imaging processing tasks, including edge detection, image smoothing, white noise suppression and, suppression or extraction of periodic features. All these tasks involve filtering in the wavevector domain. Image filtering can be implemented electronically. However, in big-data applications requiring real-time and high-throughput image filtering, conventional digital computations become challenging. Nanophotonics-based optical analog computing may overcome this challenge by offering high-throughput low-energy-consumption filtering using compact devices. Here, we show that several types of isotropic two-dimensional image filters can be implemented with a single photonic crystal slab device. Such a device is carefully designed so that the guided resonance near the Γ point exhibits an isotropic band structure. Depending on the light frequency and the choice of transmission or reflection mode, this compact device realizes isotropic high-pass (Laplacian), low-pass, band-reject and band-pass filtering in the wavevector domain. We numerically demonstrate various important image processing tasks enabled by these filters as mentioned above. Our work points to new opportunities in optical analog computing as provided by nanophotonic structures.
We study the ring resonator under a dynamic modulation. Each ring resonator supports a set of resonant modes with an equal spacing. We find that the system exhibits a spectral Bloch oscillation along the frequency axis when we introduce a frequency detuning in the modulation frequency. A periodic switching of the detuning brings out a unidirectional translation of the frequency of light. Moreover, in an array of rings, each of which is dynamically modulated with a different phase, we see topologically-protected edge states. Our work points to a new capability for the control of light in the frequency space.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.