Electromagnetically Actuated Variable Optical Attenuator With Configurable Dynamic Range

A variable optical attenuator (VOA) based on magnetically induced micro-displacement with a configurable dynamic range is proposed. The copper coil wound around the input fiber collimator, driven by precisely controlled low currents, generates a magnetic field that couples with the paired bar magnets to achieve lateral displacement, enabling continuous optical attenuation. By varying the inclination angle $\alpha $ (0-90°) of the magnet pairs relative to the horizontal plane, the system simultaneously achieves both wide-range optical attenuation and precision-tunable optical coupling efficiency. Experimental results show that within the 0–20 mA current range, adjusting the angle $\alpha $ modifies the attenuation control precision, thereby enabling configurable dynamic ranges. Specifically, attenuation ranges of approximately 20 dB, 40 dB, and 60 dB are achieved at $\alpha = 0^{\circ }$ , 45° and 90°, respectively, allowing the device to be adapted to various application scenarios.