Phase measurement and compensation method for a waveguide beam based on an on-chip 90° optical hybrid mixer

Phase measurement and compensation are important for high-performance optical communication systems. Previous studies have shown that most phase compensation methods rely on modifying the optical path or structure of the 90° optical hybrid mixer, which increases system complexity and cost. For highly integrated on-chip 90° optical hybrid mixers, however, such structural modification is impractical, creating a need for a flexible post-processing compensation approach. To address this, we propose a method that retrieves phase information from optical intensity measurements to determine the four output phases of the mixer. A compensation method is introduced that reconstructs the phase relationships at the mixer's outputs without modifying the chip. First, simulations verify the effectiveness of the algorithm, demonstrating that the maximum phase error is reduced from 14.62° to 6 × 10^-4°. Based on this, a compensation matrix is constructed to reconstruct the signal phase relationships, thereby enhancing measurement accuracy. Experimental results confirm that the compensated phase error can be controlled within 4.21°. Compared with traditional schemes, the proposed method accomplishes phase compensation without complex optical setups, offering a practical solution for integrated photonic systems.