Single-Chip Ring Resonator-Based 1 $\times$ 8 Optical Beam Forming Network in CMOS-Compatible Waveguide Technology

All-Optical Delay Module Using Cascaded Polymer All-Pass-Filter Ring Resonators

“…A electronic resonance effect provides the lowest group velocity while the narrow bandwidth and the low temperature operation make it impractical for the use in large-capacity optical communication system [2][3][4][5][6][7]. Several GHz bandwidth and 0.3 bit delay have been reported using a phonon transition phenomenon resulting from stimulated Brillouin scattering along a few km long silica optical fiber, but it is still impractical [4,5].…”

“…Even though this is the best reported performance in terms of bandwidth-delay product, this approach still exhibits several problems in practical employment due to a long cell length of a few centimeters resulting in integration incompatibility with the existing optical communication devices. Variable delay devices are also essential in the realization of phased array antennas [7].…”

Optical phase synchronization in coherent optical beamformers for phased array receive antennas

“…Among the several possible architectures, in [1,2] the advantages of OBFNs using optical ring resonators (ORRs) as delay elements have been demonstrated.…”

“…The issue of OPS becomes particularly sensitive when dealing with hybrid setups, where single integrated optical chips are still connected together by means of optical fibers, like in the OBFN system described in [1,2], where splitting and modulation are achieved using off-the-shelf components based on optical fibers. In this case, a number of causes (such as temperature instability, mechanical stress and vibrations) occur that desynchronize the optical phases, dramatically reducing the stability of the output signal of the system.…”

“…1. The core of the system is an ORR-based OBFN for tunable TTD generation, an optical sideband filter (OSBF) for SSB-SC modulation, and an optical carrier reinsertion circuit for balanced coherent detection, which are integrated on a single chip [2,3]. The section between laser and MZMs, and between the latter and chip are all fiber-based and thus introduce the phase instability problems.…”