Magneto-optic fiber-coupled tuneable optical attenuation

Tuneable, variable, optical attenuation through an optical circulator with a broad, linear attenuation range of triangle o (30-40) dB is demonstrated using non-reciprocal Faraday rotation in a double-pass configuration with a combination of permanent magnets and an electromagnet. A fiber-coupled magneto-optical variable optical attenuator (MVOA) operates over the near IR with an attenuation tuning range of triangle alpha > 30 dB, a resolution of triangle alpha similar to 0.02 dB, a response time of t < 2 ms, and a temperature dependence over T = 25-70 degrees C of triangle alpha / triangle T = -8 x 10(-4) dB/degrees C. At lambda =1550 nm, the calculated Faraday material effective Verdet constant is (1/A)V-eff =109 x 10(3) dB/(T.m). (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.