title: Formation and Applications of the Secondary Fiber Bragg Grating.
abstract: Being one of the most proven fiber optic devices, the fiber Bragg grating has developed continually to extend its applications, particularly in extreme environments. Accompanying the growth of Type-IIa Bragg gratings in some active fibers, a new resonance appears at the shorter wavelength. This new type of grating was named "secondary Bragg grating" (SBG). This paper describes the formation and applications of the SBGs. The formation of the SBG is attributed to the intracore Talbot-type-fringes as a result of multi-order diffractions of the inscribing beams. The SBG presents a variety of interesting characteristics, including dip merge, high-temperature resistance, distinct temperature response, and the strong higher-order harmonic reflection. These features enable its promising applications in fiber lasers and fiber sensing technology.
authors.affiliation: Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China. tguanbo@jnu.edu.cn.
authors.forename: Bai-Ou
authors.initials: BO
authors.lastname: Guan
authors.affiliation: Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China. rayiori@163.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ran
authors.affiliation: Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China. ffrhust@126.com.
authors.forename: Fu-Rong
authors.initials: FR
authors.lastname: Feng
authors.affiliation: Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China. iptjinlong@gmail.com.
authors.forename: Long
authors.initials: L
authors.lastname: Jin
keywords: Talbot effect; distributed Bragg reflector fiber laser; fiber Bragg grating; high temperature resistance; photosensitivity