Analysis Of Fiber Bragg Gratings Research Articles

Diffractive gratings with varying period’s shape

Diffractive gratings with varying period’s shape

Harmonic analysis of fiber Bragg gratings written using apodized phase and amplitude masks

espanolEn este trabajo se presentan las investigaciones teoricas sobre la respuesta armonica de las redes de Bragg de fibra apodizadas grabadas utilizando mascaras de fase y de amplitud apodizadas. Se emplean dos tecnicas de apodizacion, a saber, con escalon de fase variable y con factor de llenado variable, y se analiza ampliamente su influencia sobre la eficiencia de reflexion de las rejillas para la longitud de onda de Bragg y de su armonico. Los resultados muestran que el uso de una tecnica de apodizacion apropiada y el perfil adecuado, pueden modificar ampliamente los espectros de potencia de las redes de Bragg de fibra apodizadas. EnglishIn this paper theoretical research on harmonic response of apodized fiber Bragg gratings written using apodized phase and amplitude masks are presented. Two apodization techniques, namely variable phase step and variable fill factor are employed, and their influence on gratings’ reflection efficiency of Bragg wavelength and its harmonic is extensively analyzed. Results show that using an appropriate apodization technique and profile power spectra of apodized fiber Bragg gratings can be widely tailored.

Analysis of Fiber Bragg Gratings for the Elimination of Realignment During the Life of the System While FBG Is Spliced Directly to the Doped Fiber

Fiber Bragg Grating (FBG) is a type of distributed Bragg reflector constructed in a short segment of optical fiber that reflects particular wavelengths of light and transmits all others. This is achieved by creating a periodic variation in the refractive index of the fiber core, which generates a wavelength-specific dielectric mirror. A fiber Bragg grating can therefore be used as an inline optical filter to block certain wavelengths, or as a wavelength-specific reflector.

Experimental and theoretical analysis of fiber Bragg gratings under Transverse Force to a Small Grating Section

Fiber Bragg grating under transverse force on a small grating section is studied by numerical simulation and experimentation. A numerical simulation based on the transfer matrix method is used to calculate the consequent changes in reflected spectrum. The reflected spectra of the FBG subjected to the transverse force split into two main peaks, and the split point shifted linearly and periodically versus the applied force. The split point is shifted in the bandwidth with the period of 11N, and the sensitivity of the split point wavelength shift versus the applied force is 0.05 nm/N in one period. The experimental results show good agreement with the simulation analysis.

Microwave V-I transmission matrix formalism for the analysis of photonic circuits: application to fiber Bragg gratings

We propose the use of V-I matrices well known in microwave engineering to the analysis of photonic devices, especially those based on multilayer dielectrics. As an application we present a novel fast effective index method for the analysis of fiber Bragg gratings based on the use of V-I transmission matrices. It combines the exactitude of traditional effective index methods and the speed of coupled-mode methods.

Experimental and theoretical analysis of fiber Bragg gratings under lateral compression

In this paper, an experimental investigation is presented on reflection spectra of fiber Bragg gratings (FBG) under lateral compression together with the theoretical analysis. The coupled mode theory has been employed, by considering the LP x and LP y modes, to obtain accurate results for optical responses of FBG with compression-induced birefringence. The effects of polarization states of the incident light and compression conditions have also been investigated. Good agreements between experimental results and numerical simulations have been obtained.

Analysis of fiber Bragg gratings by a side-diffraction interference technique

A new nondestructive, noncontact, and sensitive technique for fiber Bragg grating geometry and index-fault location measurements is presented. Two plane-wave probe laser beams are incident upon the grating from the side at angles that satisfy the Bragg-reflection condition. An interference pattern is formed behind the fiber between the first-order diffracted beam (from one probe beam) and the zero-order transmitted beam (from the second probe beam). The axial grating index modulation and the grating period are functions of the fringe visibility and the fringe period, respectively. The method is sensitive and is applicable even in the case of relatively weak gratings. Unchirped and chirped Bragg gratings have been studied with the proposed technique. We demonstrate accuracies of 1 x 10(-4) for measurement of the index modulation and 0.01 nm for measurement of the period. As well as for the analysis of most already-fabricated gratings, this technique is useful for in situ analysis of a long fiber Bragg grating as such a grating is translated along its axis during the fabrication process.

Analysis of fiber Bragg gratings for dispersion compensation in reflective and transmissive geometries

Numerical analysis of the dispersion-compensating properties of fiber Bragg gratings (FBGs) in both reflective and transmissive modes is presented. First, the sensitivity of chirped, reflective gratings to the grating chirp parameter, index modulation, and grating length is examined, showing that apodization provides lower sensitivity to variations in these parameters. Second, we introduce a new transmissive geometry for grating-based dispersion compensation that utilizes the dispersive properties of a uniform Bragg grating in transmission.