Optical switching optimization with nonlinear coupler-integrated polymer phase shifters

This study introduces and substantiates the operational viability of a novel optical switch, realized through a multimode interference (MMI)-based Y-branch architecture, and holds significant promise for advancing optical circuitry. Implementing a nonlinear directional coupler (DC) within symmetric arms of the Y-branch structure enables controlled phase shifting, effectively transforming the passive splitter into an active switch. Phase manipulation results in ON and OFF states, which is crucial for versatile optical switching. With a 5 μm core width to ensure single-mode operation, the design is fine-tuned using the beam propagation method (BPM) at 1550 nm, focusing on self-imaging and the transfer matrix method. The proposed step index (SI) Y branch MMI splitter exhibits an impressive 86% power-splitting efficiency. The analysis reveals a low excess loss of 0.64 dB for both TE and TM modes and minimal polarization dependence loss (PDL) at 0.000007 dB, highlighting its potential for high-performance optical switching.