Force sensing method, light-sensitive stress sensor and force sensing system

The invention discloses a force sensing method, a light-sensitive stress sensor and a force sensing system.The method comprises the steps that the two ends of a sensing optical fiber engraved with a first fiber grating and a second fiber grating are fixed in an elastic body, multiple sets of characteristic parameters of the gratings are obtained, and at least one set of parameters are made to be different; placing the elastomer in a to-be-measured environment, and obtaining a central wavelength drift distance of the grating after the elastomer is subjected to a to-be-measured force; calculating to-be-measured force borne by the elastomer according to the central wavelength drift distance and all the characteristic parameters; the characteristic parameters comprise the central wavelength, the effective elasto-optical coefficient, the elastic modulus, the thermal expansion coefficient, the thermo-optical coefficient and the sectional area of the grating. Through the arrangement, the force to be measured on the