Fiber Bragg gratings with various chirp profiles made in etched tapers

Abstract

We have studied, both theoretically and experimentally, fiber Bragg gratings with a number of different chirp profiles. These chirp profiles can easily be achieved by a recently demonstrated technique involving a taper of desired profile etched into the cladding of a fiber. The performances of gratings with linear, quadratic, periodically modulated, and step-chirp profiles are analyzed numerically. The versatility of the technique was demonstrated when linearly and quadratically chirped gratings were made as examples of continuous chirp, and gratings with step chirps were made as examples of discontinuously chirped structures.

Analysis of fiber Bragg grating with exponential–linear and parabolic taper profiles for dispersion slope compensation in optical fiber links

“…Considering the refractive index changes with the applied strain because of the photo-elastic effect, the change of Bragg wavelength at original point is given by [16] …”

Dispersion compensation using linearly chirped polymer fiber Bragg grating

“…To simulate the output reflectivity of a chirped fiber grating, we consider the scattering method [2]. Suppose an arbitrary grating is divided into N short sections in which the grating are assumed to be uniform.…”

“…Similarly, the thermal strain coefficient in a POF is 1.48 pm/µε, compared with 1.15 pm/µε for silica. Linearly chirped POFs are used for dispersion compensation, wavelength division multiplexing (WDM), pulse shaping filters, distributed feedback lasers, and sensors [2].…”

Spectra power and bandwidth of fiber Bragg grating under influence of gradient strain

“…Most of the researches focus on the wavelength sensing technology and theory, but when the inhomogeneous field applying on the FBG, such as the gradient stain and gradient temperature, acts on the grating range of the FBG, which can lead to the FBG chirping, and the reflective spectrum shows new features, such as reflective power and reflective bandwidth [6][7][8][9][10]. It has many methods to form inhomogeneous refractive-index modulation, such as designing the grating structure [11,12], introducing a strain gradient by designing an especial fabrication structure [13,14], and etching the FBG [15]. The essence of the inhomogeneous field modulation induces a refractive-index gradient.…”