Analysis and Development of a Tunable Fiber Bragg Grating Filter Based on Axial Tension/Compression

Abstract

Fiber Bragg gratings (FBGs) are key elements in modern telecommunication and sensing applications. In optical communication, with the advancement of the Erbium doped fiber amplifier (EDFA), there is a great demand for devices with wavelength tunability over the Erbium gain bandwidth (in particular, for wavelength division multiplexing (WDM) networks). The center wavelength of a FBG can be shifted by means of change of temperature, pressure or mechanical axial strain. The axial strain approach is the best method among all other techniques because it allows relatively large wavelength shifts with high speed. Axial strain of up to 4% will be required to cover the whole EDFA region (more than 40 nm of central wavelength shift). The formation of Bragg grating results in significant reduction in mechanical strength of optical fibers especially in tension. As a result, axial strain of only about 1% can be achieved by mechanical stretching of FBGs. In order to achieve the remaining 3% strain compression of FBGs has to be applied.In this thesis, the design and analysis of a novel device for achieving central wavelength shift are presented. In particular, the device has achieved, for a fiber with Further, using the piezoelectric transducer (PZT) actuator as a driver, tuning speed of around 1.5nm/ms was achieved.-iii - ACKNOWLEDGMENTSUpon the completion of this thesis, I would like to express my sincere gratitude and appreciation to my supervisors Professor Chris W.

Fabrication of chirped fiber Bragg gratings by simple combination of stretching movements

“…A corresponding wavelength shift of 15.7 nm has been reported [15]. Moreover, the maximum bandwidth could be increased to up to 56.5 nm if the writing system is improved to work in a compression/tension regime as proposed in [16].…”

Bend Sensor Using Fiber Bragg Gratings to Determinate the Distance from the Sensor to the Neutral Axis in Compression and Extension

“…Para la medición de la longitud de onda reflejada, se realizaron desplazamientos horizontales variables sobre un extremo de la lámina, por medio de una prensa mecánica [13] y los desplazamientos en la altura de la lámina eran cada 2mm. Se logró un barrido de 21 muestras por FBG en el experimento.…”

Transition Region Effects in Tunable Fiber-Based Wavelength-Selective Devices

“…where ε z (t) is axial strain, p e = 0.22 is the effective photoelastic coefficient [35], ∆L z is the axial displacement and L z is the stressed length. The required strain can be induced via a piezoelectric transducer (PZT).…”