Complex Bragg grating writing using direct modulation of the optical fiber with flexural waves

Abstract

A flexural wave is applied to an optical fiber during the process of Bragg grating inscription using the direct writing method through a phase mask. Using this approach, we can dither the writing process to allow complex grating writing. Examples we demonstrate are tunable sampled gratings and phase-shifted gratings.

OSSB modulation of tunable optical carrier-to-sideband ratio with FBG-based acousto-optic tunable filter

“…Supposing T A and T B represents the factor of primary and secondary transmission deep separately, then the range of T A /T B can be calculated as 0.18-1.80, 0.06-2.83 and 3.91 10 4 × − -32. 22, respectively. When the modulation depth of FBG-AOTF refractive index changes, the range of T A /T B will be different.…”

“…Since a fiber Bragg grating based AOTF (FBG-AOTF) which is also named as FBG based acousto-optic superlative modulator has been proposed by Liu et al [12], the research in the FBG-AOTF has observed a great development [13][14][15][16][17][18][19]. Because the spectral and wavelength can be controlled by the acoustic wave (AW), the FBG-AOTF can be widely applied in add-drop multiplexer [20], fiber laser [21], and grating writing [22].…”

Tunable acoustic bursts for customized tapered fiber Bragg structures

“…Recently, the effect of applying an acoustic flexural wave longitudinally to an optical fiber during the process of Bragg grating inscription using the direct writing method through a phase mask was demonstrated and showed that it can be used to obtain precise control over the grating parameters in order to achieve sampled gratings and phase-shifted gratings [12]. However, regarding the generation of cavities for phase shift, only preliminary results have been presented.…”

“…This technique has made possible the development of a vast range of devices, such as distributed feedback fiber lasers [2,3], optical narrowband filters [4], optical code division multiple access en/decoders [5,6], multiplexers/demultiplexers [7] and so on, that are based on, for example, phase-shifted gratings [8] and sampled gratings [9][10][11]. In this paper, we present a modified methodology previously demonstrated in [12], where a direct acoustic modulation of the fiber is used, however using only the set of the acoustic burst time characteristics.…”

Acousto-optic modulation in a microstructured plastic optical fibre Bragg grating

“…It has been successfully applied in the design and construction of various low insertion loss all-fibre devices such as a tunable dispersion compensator, tunable optical notch filter [6,7] and complex Bragg grating writing [8], among others. Also, using a LPG, a viscosity and density sensor was reported [9].…”