Title :
Mode coupling and phase modulation in vibrating waveguides
Author :
Kajenski, Peter J. ; Fuhr, Peter L. ; Huston, D.R.
Author_Institution :
Dept. of Electr. Eng., Vermont Univ., Burlington, VT, USA
fDate :
9/1/1992 12:00:00 AM
Abstract :
When coherent light is coupled into a multimode waveguide (such as a fiber), a speckle pattern is formed at the fiber output. When the fiber is vibrated, the speckle pattern is modulated due to mode coupling and phase modulation of the waveguide modes. It is shown that when a highly coherent light source is used, the speckle pattern modulation is due primarily to phase modulation of the modes. When less coherent sources are used (such as low-cost laser diodes), mode coupling is the dominant effect
Keywords :
fibre optic sensors; optical fibre theory; optical modulation; phase modulation; speckle; vibration measurement; vibrations; coherent light; mode coupling; multimode fibre vibration sensor; multimode waveguide; phase modulation; speckle pattern; vibrating waveguides; Acoustic waveguides; Interference; Optical coupling; Optical fiber communication; Optical fibers; Optical modulation; Optical waveguide theory; Optical waveguides; Phase modulation; Speckle;
Journal_Title :
Lightwave Technology, Journal of
