Optimized reconfigurable ultra-compact mode converter device utilizing Sb2Se3 for TE0 and TE1 mode conversion

This paper presents an optimized, reconfigurable, ultra-compact mode converter device designed for efficient conversion between transverse electric (TE) modes, specifically TE₀ and TE₁. The mode conversion is achieved through the manipulation of an antimony selenide (Sb₂Se₃) phase-change material (PCM) layer, integrated on the top surface of a silicon waveguide. The device’s performance was investigated numerically at a wavelength of 1550 nm, focusing on optimizing the size of the phase-change layer to enhance transmission and minimize losses. With a footprint of just 4 μm × 3 μm, this converter is highly suitable for integrated photonic systems, including optical communication, signal processing, and photonic circuits. The dynamic reconfigurability is facilitated by the reversible phase transitions of Sb₂Se₃ between its amorphous and crystalline states, enabling low-loss mode conversion. By leveraging this material and its properties, the converter achieves high transmission efficiency with minimal insertion loss. These findings pave the way for more compact and efficient photonic devices, addressing the critical demand for reconfigurable mode converters in integrated photonics. This work represents a significant advance in device performance and footprint reduction, positioning it as a state-of-the-art solution for next-generation photonic applications.