The optical vortex interferometer(OVI)has been found to have extensive applications in precision metrology due to its ultrahigh sensitivity.However,most current implementations rely on free-space optical components,pa...The optical vortex interferometer(OVI)has been found to have extensive applications in precision metrology due to its ultrahigh sensitivity.However,most current implementations rely on free-space optical components,particularly requiring beam splitter cubes to combine sensing and reference beams.This inevitably necessitates complex coaxial alignment of optical paths,where tilt,divergence,and centroid misalignment introduce significant challenges in phase demodulation.This paper presents an all-fiber OVI where beams interfere through a mode selective coupler.The orbital angular momentum order difference,which directly determines the sensitivity of the OVI,is reduced to one.A novel,to our knowledge,measurement and phase demodulation methodology is developed for the optical fields generated by the proposed interferometer,accompanied by systematic analysis of error sources and their magnitudes.The proposed OVI was applied to temperature sensing,achieving a sensitivity of 44.19 rad∕(℃·m),which is 2-3 orders of magnitude higher than that of conventional methods.The proposed OVI and corresponding demodulation approach show promising potential for ultrahigh-precision sensing applications.展开更多
基金National Natural Science Foundation of China(62375143,62505145)。
文摘The optical vortex interferometer(OVI)has been found to have extensive applications in precision metrology due to its ultrahigh sensitivity.However,most current implementations rely on free-space optical components,particularly requiring beam splitter cubes to combine sensing and reference beams.This inevitably necessitates complex coaxial alignment of optical paths,where tilt,divergence,and centroid misalignment introduce significant challenges in phase demodulation.This paper presents an all-fiber OVI where beams interfere through a mode selective coupler.The orbital angular momentum order difference,which directly determines the sensitivity of the OVI,is reduced to one.A novel,to our knowledge,measurement and phase demodulation methodology is developed for the optical fields generated by the proposed interferometer,accompanied by systematic analysis of error sources and their magnitudes.The proposed OVI was applied to temperature sensing,achieving a sensitivity of 44.19 rad∕(℃·m),which is 2-3 orders of magnitude higher than that of conventional methods.The proposed OVI and corresponding demodulation approach show promising potential for ultrahigh-precision sensing applications.
