PURPOSE: To widen a measuring range in a state that a high measurement accuracy remains held, by constituting the titled sensor of a three-dimensional optical waveguide circuit containing plural pieces of interferometers, a phase shift means for giving a phase shift to an optical wave passing through one optical waveguide part of each interferometer, and a means for applying in common a pressure to be measured to the other optical waveguide, etc.
CONSTITUTION: Light which is inputted to an optical waveguide 50 on a substrate 1 is made to branch equally into two and inputted to Mach-Zehnder type interferometers 20, 30. On branching optical waveguides 23, 34 of the interferometers, phase shifting pads 25, 35 are formed, and also an optical waveguides 24, 33, protective pads 26, 36 for applying a pressure to be measured are formed. On the other hand, by a pressure applying mechanism 17 consisting of a rectangular pressure member 40, a rod 41, and an elastic plate 43 which is fixed to its upper end and functions as a cover of a housing 42, an applied pressure is applied equally to the protective pads 26, 36. Also, since a different phase shift is given in advance to one optical waveguide part, plural optical interferometers take partial charge of plural different measuring ranges, and the measuring range is widened as a whole.
MATANO MASAHARU
YAMASHITA MAKI
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