Dual-Wavelength Interferometric Stabilization Using SLMs: Demonstration With Dual-Phase Modulation Mode Conversion

In this paper, an interferometric stabilization method based on dual-wavelength compensation with spatial light modulators (SLMs) is proposed. Dual-phase modulation (DPM) is employed as a representative application to demonstrate the principle in mode-division multiplexing (MDM) systems. Although DPM can achieve efficient mode conversion by exploiting interference rather than diffraction, its practical use has been severely constrained by environmental disturbances such as air turbulence, temperature variations, and mechanical vibrations, which induce phase drift and degrade conversion stability. To address this limitation, we introduce a dual-wavelength monitoring and SLM based feedback scheme that enables real-time detection and compensation of phase drift, thereby maintaining stable interference. The performance of the stabilization system is further evaluated under different interferometer arm lengths and control parameters. Experimental results show that the proposed approach effectively suppresses phase fluctuations in short-arm interferometers and ensures stable mode conversion with low modal crosstalk. While mode conversion is used as the experimental example, the proposed scheme is applicable to a broader class of interferometric systems requiring stable complex-field generation and is promising for high-capacity optical communication networks.