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• We firstly propose a cascaded Kerr beam self-cleaning scheme that combines multiple MMFs to further improve multimode beam quality. • Radial offset between fiber 1 and fiber 2 of the cascaded multimode fiber system should be as small as possible for cascaded beam self-cleaning. • Our results also suggest that an increased number of HOMs with negligible energy along with a higher number of cascaded fibers contribute to superior multimode beam quality. Spatial beam self-cleaning has shown a nonlinear improvement in beam quality in multimode fibers (MMFs), proving its value in high-power fiber lasers and nonlinear biomedical imaging. In this Letter, we propose a novel cascaded Kerr beam self-cleaning scheme that combines multiple MMFs to further improve beam quality. Through this scheme, the initially speckled beam gradually evolves into a well-defined bell-shaped, primarily dominated by the fundamental mode, after undergoing two or three cascaded self-cleaning processes. Simulation results also suggest that an increased number of high-order modes (HOMs) with negligible energy along with a higher number of cascaded fibers contribute to superior beam quality. This phenomenon is attributed to the new excited HOMs acting as attractor and facilitating an energy cascade towards the fundamental mode. [ABSTRACT FROM AUTHOR]

• Low-cost fiber MI temperature sensor is formed by filling SCF with polymer-UV glue. • High sensitivity is obtained due to the great thermal properties of UV glue. • Our sensor shows advantages of robust, small size, and low cost. • The reflective tip structure enable for remote sensing in practical applications. A low-cost fiber tip temperature sensor is proposed and experimentally demonstrated. It is based on the Michelson interferometer (MI) structure which is partially filled with polymer-UV glue in the suspended core fiber (SCF). Due to the greater thermal properties of UV glue compared with the silica optical fiber, the length of the inner cavity in the MI structure is susceptible to temperature modulation, resulting in the interference wavelength drift. Experimental results show that the sensor achieves a sensitivity of −164 pm/°C in the temperature range of 25–60 °C, and the sensor offers good wavelength and power stability at room temperature. In addition, the sensor has advantages such as robust, small size, and low cost, especially the reflective tip structure is more suitable for remote sensing in practical applications. [ABSTRACT FROM AUTHOR]