title: In-fiber reflection mode interferometer based on a long-period grating for external refractive-index measurement.
abstract: We present two novel schemes for refractometry based on a long-period fiber grating- (LPG-) based Michelson interferometer. These schemes are designed to overcome the measurement dependence of previously demonstrated LPG-based refractometry on the immersion depth. The first utilizes an unshielded LPG and the second, a shielded one. Both schemes were tested over a certain refractive-index range, and the measurement of glucose concentration in water was experimentally demonstrated. In addition, the temperature sensitivity of the two schemes is discussed.
authors.affiliation: Center for Photonics Technology, Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0111, USA. dakim1@vt.edu
authors.forename: Dae Woong
authors.initials: DW
authors.lastname: Kim
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kristie L
authors.initials: KL
authors.lastname: Cooper
authors.forename: Anbo
authors.initials: A
authors.lastname: Wang