Ultra-compact on-chip optical filters with narrow bandwidth

A novel scheme for integrated optical filters with narrow bandwidth is proposed to dramatically improve its compactness on the basis of slow-light waveguide, which provides a large optical path in a short geometry length. By introducing the one-dimensional grating waveguide (ODGW), a kind of slow-light waveguide, into a micro-ring resonator (MRR), the area of MRR is reduced by three orders of magnitude compared to the MRR without ODGW. As a proof of concept, an ultra-compact on-chip filter with narrow bandwidth of 2.1 pm (263 MHz) is conceived by cascading six MRRs with ODGW. Additionally, the designed optical filter shows excellent performances of roll-down speed, out-of-band signal suppression, and in-band ripple. Our proposal offers a promising solution to miniaturize the integrated optical filters with narrow bandwidth, and hence improve the integration density of on-chip photonic networks.

Dispersionless one-way slow wave with large delay bandwidth product at the edge of gyromagnetic photonic crystal

We theoretically, demonstrate a high delay bandwidth product (DBP) and zero group velocity dispersion (GVD) in a two-dimensional one-way slow light waveguide. The waveguide consists of gyromagnetic photonic crystal (GMPC) and a cladding formed by silicon photonic crystal. At the edge of the band, weak interactions (“semi-anticrossing”) between the chiral edge state (CES) mode and the mode localized at the surface of cladding are observed. The group velocity of CES wave can be tuned by adjusting the modal field distribution. As a result, an extraordinarily large value of normalized DBP of 0.63 with a group index of 10.32 and a bandwidth ranging from [Formula: see text] to [Formula: see text] is obtained. This result may contribute to one-way slow light applications in information communication systems.

Patterned waveguide liquid crystal displays

A polymer stabilized LC based light waveguide display is reported. Performance is improved by patterned photo-polymerization or electrode. It has high brightness, ultrafast switching time, high contrast ratio, and high transmittance for transparent and augmented displays.