Rapid fabrication of microhole array structured optical fibers

A microhole array in a common single-mode fiber is fabricated by selective chemical etching of femtosecond-laser-induced fiber Bragg grating (FBG), which has a laser-modified region extending from the fiber core to the cladding-air boundary due to laser self-focusing. The shape and size of the orderly microhole on the fiber surface are controlled via changing conditions of FBG fabrication and chemical etching. A simultaneous sensing for surrounding refractive index and temperature is demonstrated by this microhole array FBG through measurement of the transmission power change and Bragg resonant wavelength shift.