High sensitivity and anti-external interference dual-parameter sensor based on a multimode slotted photonic crystal nanobeam cavity

We put forward a multimode slotted nanobeam cavity (MM-SPCNC) supporting both air and dielectric modes through a specific design of band properties. Dual-parameter detection is realized by jointly measuring the resonance wavelength shifts of both air and dielectric modes. The proposed sensor is robust against external interference and shows higher sensitivity compared with other dual-parameter sensors. The maximum external interference ranges of the proposed sensor are 4.82x10(-6) and 0.05 for refractive index (RI) and temperature (T), respectively, which indicates that the sensor can effectively resist against external interference. The RI and T sensitivities of the fundamental air mode are 421 nm/RIU and 58 pm/K respectively, whereas those of the fundamental dielectric mode are 706 nm/RIU and 46 pm/K respectively. The proposed sensor thus represents a promising candidate for future multifunctional and lab-on-chip sensing applications.