Giant Goos–Hänchen shifts of waveguide coupled long-range surface plasmon resonance mode**Project supported by the National Natural Science Foundation of China (Grant Nos. 61505111 and 11604216), the China Postdoctoral Science Foundation (Grant No. 2016M600667), the Science and Technology Planning Project of Guangdong Province, China (Grant No. 2016B050501005), the Fund from the Educational Commission of Guangdong Province, China (Grant No. 2016KCXTD006), and

Abstract

A hybrid structure based on a planar waveguide (PWG) mode coupling a long-range surface plasmon resonance (LRSPR) mode is proposed to enhance the GH shift. Both the PWG mode and LRSPR mode can be in strong resonance, and these two modes can be coupled together due to the normal-mode splitting. The largest GH shift of PWG-coupled LRSPR structure is 4156 times that of the incident beam, which is 23 times and 3.6 times that of the surface plasmon resonance (SPR) structure and the LRSPR structure, respectively. As a GH shift sensor, the highest sensitivity of 4.68 × 107λ is realized in the coupled structure. Compared with the sensitivity of the traditional SPR structure, the sensitivity of our structure is increased by more than 2 orders, which theoretically indicates that the proposed configuration can be applied to the field of high-sensitivity sensors in the future.