Topological Nanophotonic Wavelength Router Based on Topology Optimization

The topological nanophotonic wavelength router, which can steer light with different wavelength signals into different topological channels, plays a key role in optical information processing. However, no effective method has been found to realize such a topological nanophotonic device. Here, an on-chip topological nanophotonic wavelength router working in an optical telecom band is designed based on a topology optimization algorithm and experimentally demonstrated. Valley photonic crystal is used to provide a topological state in the optical telecom band. The measured topological wavelength router has narrow signal peaks and is easy for integration. This work offers an efficient scheme for the realization of topological devices and lays a foundation for the future application of topological photonics.

A Large-Capacity Optical Switch Design for High-Speed Optical Data Centers

Due to the emergence of high-speed applications, demand for more bandwidth has increased exponentially in last a few years. To serve each user for his demand very fast processing and propagation of data is desired. These two requirements of high-speed communication can be fulfilled using optical fiber technology. In the same view in past many optical switch designs have emerged with their respective advantages and disadvantages. This paper proposes a wavelength division multiplexing (WDM)-based switch incorporating arrayed waveguide grating (AWG) as wavelength router and fiber delay lines (FDL) to create optical buffer. Proposed switch design is compared with recent switch design and it is found that both in terms of BER and packet loss probability the performance of proposed design is much better in comparison to earlier designs.

Generalization of an Optical ASA Switch

An arrayed waveguide grating (AWG) is a kind of passive wavelength router, and it is the most promising technology for developing large optical switches. However, AWGs have poor scalability, and using small AWGs to construct a large switch has been done in many prior works. A novel AWG-based switch called ASA (AWG, Space switching, AWG) that does not use wavelength converters has been proposed. It can expand the switch size from N to N2 by using N × N AWGs. In this paper, we generalize the ASA switch by using only N × N AWGs, N × N space switches, and N wavelengths such that the switch size is expanded to Nt for any positive integer t. Since each port of an N × N AWG can transmit up to N wavelengths simultaneously, the total capacity of the generalized ASA switch is extended to be close to Nt+1 × the bandwidth of a wavelength channel, provided that the inputs which are located in the same port position of each input AWG are destined to distinct outputs.