Optical add/drop mux-demux using arrayed waveguide grating

Abstract

Optical networks are known for their high bandwidth and speed advantages, but crosstalk remains a problem. A solution to address crosstalk in optical add-drop multiplexers (OADMs) is the proposed approach using a foldback path, optical circulator, and optical switches. This creates a reconfigurable OADM with significantly reduced signal crosstalk. The design uses an N x N arrayed waveguide grating (AWG) with a loop in the optical path to reflect the signal back into the AWG. Optical switches allow for selective signal adding or dropping, while two AWGs enable reconfigurable setups for signal addition or dropping. Data transmission rates of 5 Gbps to 25 Gbps have been successfully tested, with increasing Bit Error Rates up to 0.009 at 25 Gbps. The quality factor has been analyzed using an eye diagram to ensure reliable data transmission. The eye diagram shows the signal quality visually, with the opening and closing of the eye pattern. The proposed design has a high-quality factor and eye-opening, making it a promising solution for high-speed optical networks. The incorporation of a ring resonator at the output waveguide led to a reduction in cross talk from 0.1 to 0.05. Through careful tuning of the ring resonator, we were able to successfully perform signal dropping. However, the ring resonator exhibited lower coupling efficiency, resulting in incomplete signal power drop. In contrast, the racetrack resonator demonstrated superior coupling efficiency, enabling full signal drop.