Few-mode fiber Bragg grating （FM-FBG） has wide applications in the field of multi-wavelength fiber lasers and fiber-optic sensing. In this letter, FBG is successfully written in a novel type of FM fiber （FMF） based on 248-nm excimer laser and a uniform phase mask. A low-loss coupling between the FMF to a single- mode fiber is realized by a graded-index multi-mode fiber with a length of about a quarter pitch. The sensing properties of the FMF grating are further investigated. The experimental results indicate that the novel FM-FBG has sensitivities of temperature, strain, and bending of 11.2 pm/~C, 1.3 pm/pg, and 636.9 pm/m-1, respectively.
A new type of cavity polariton,the optical Tamm state（OTS） polariton,is proposed to be realized by sandwiching a quantum well（QW） between a gold layer and a distributed Bragg reflector（DBR）.It is shown that OTS polaritons can be generated from the strong couplings between the QW excitons and the free OTSs.In addition,if a second gold layer is introduced into the bottom of the DBR,two independent free OTSs can interact strongly with the QW excitons to produce extra OTS polaritons.
