Patent ID: 7843570

Claim:
A substance adsorption detection method using the sensor having a crystal oscillator, the method comprising: providing a sensor with an optical waveguide path disposed on the crystal oscillator, said crystal oscillator comprising a crystal and electrodes formed on either face of said crystal, wherein said optical waveguide path is an optical waveguide layer which has a clad portion and a core arranged on said clad portion, said core being made of a higher refractive index medium than said clad portion, both said core and said clad portion being stacked on said crystal oscillator; providing light inputting means and light emitting means positioned on end portions of said optical waveguide path on which a detection target substance is adsorbed, wherein said light inputting means for allowing light to enter said core is provided on one end portion thereof and said light emitting means for acquiring light from said core is provided on the other end portion thereof; exposing said sensor to said detection target substance, while inputting light through said light inputting means to said core of the optical waveguide path; and measuring an oscillation characteristic of said crystal oscillator and light transmitted on said optical waveguide path through said core while the light is repeatedly reflected in said core, said light being emitted through said light emitting means.