D-type photonic crystal fiber surface plasma resonance multi-parameter sensor

The invention provides a D-type photonic crystal fiber (PCF) surface plasma resonance (SPR) sensor capable of simultaneously realizing multi-parameter (temperature, magnetic field intensity and refractive index) detection. According to the D-type PCF, a magnetofluid and a temperature-sensitive medium are introduced into two air holes in the two sides of a fiber core respectively to form a channel1 and a channel 2. metal films are coated on the side-throwing plane of the D-shaped PCF and the inner walls of the channel 1 and the channel 2; a refractive index sensing channel is formed by utilizing an SPR effect; a magnetic field sensing channel is formed by utilizing the magneto-optical effect of the magnetic fluid; and meanwhile, a temperature sensing channel is formed by utilizing the temperature-sensitive effect of the temperature-sensitive medium so that the sensor for simultaneously detecting multiple parameters of temperature, magnetic field intensity and refractive index is designed. The sensor has the advantages that: the defect of single measurement of the conventional optical fiber sensor is overcome, and simultaneous detection of multiple parameters is realized; in addition, the D-shaped structure reduces the distance between the sensor and the fiber core, so that the sensor quickly detects the change of the liquid to be detected, and high-sensitivity sensing is realized.