title: Refractive index sensor based on a microhole in single-mode fiber created by the use of femtosecond laser micromachining.
abstract: A compact in-fiber refractive index (RI) sensor is presented that is based on a microhole created in a conventional single-mode fiber by the use of femtosecond laser micromachining. The transmission properties of such a device with a microhole of different diameters have been investigated in the wavelength region of 1500-1600 nm and in the RI range of 1.30-1.45. It is found that the relationship between the transmission and the RI is critically dependent on the size of the microhole in the fiber core region. The highest resolution obtained is 6.70x10(-5), in the RI range of 1.37-1.42, when the microhole diameter is approximately 8 microm, close to the fiber core size. The in-fiber RI sensor developed in this work is easy to fabricate and can be used to implement temperature-independent measurements.
authors.affiliation: Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: D N
authors.initials: DN
authors.lastname: Wang
authors.forename: Minwei
authors.initials: M
authors.lastname: Yang
authors.forename: Wei
authors.initials: W
authors.lastname: Hong
authors.forename: Peixiang
authors.initials: P
authors.lastname: Lu
mesh_terms: D053685:Laser Therapy; D007834:Lasers; D016014:Linear Models; D055616:Microtechnology; D012031:Refractometry / Q000379:methods*; D013696:Temperature; D013997:Time Factors