In order to solve the problem of cross sensitivity of temperature and strain that generally exits in fiberoptic sensor,the strain and temperature sensing characteristics of LP01 and LP02 mode interference based on the inter-modal interference principle of the few mode fiber are studied,and phase sensitivity theory of inter-modal interference sensing is analyzed in detail.A temperature-insensitive strain-sensing few mode fiber with core diameter of 15.1μm,core refractive index of 1.4512 at 1550nm and claddin...