Characterization of Fiber Bragg Gratings for Dispersion Compensation

Characterization of Fiber Bragg Gratings for Dispersion Compensation http: //paginas. fe. up. pt/~ee 99113/ L. M. Ramos 1, 2, R. P. Ramos 1, 2, H. M. Salgado 1, 2 INESC Porto - Unidade de Optoelectrónica e Sistemas Electrónicos , 4169 -007 Porto, Portugal 2 Faculdade de Engenharia da Universidade do Porto, 4200 -465 Porto, Portugal 1 OBJECTIVES: MEASUREMENT SETUP: • Characterization of Fiber Bragg Gratings • Implementation of measurement setup • Software for control and data acquisition • Data analysis: delay, bandwidth, ripple Network Analyzer operation: • Continuous Wave (CW) mode DELAY MEASUREMENT: • Control of sweep time • Control of number of points Fig. 2: Setup for measurement of amplitude and group delay, with the Phase Shift method. DISPERSION COMPENSATION: DEVELOPED SOFTWARE: Fig. 1: Dispersion compensation using a chirped Fiber Bragg Gratings are passive components that work as optical filters. Their singular characteristic makes them useful for dispersion compensation. Underlying intramodal dispersion is the broadening of the pulse. A chirped Bragg grating introduces different delays at different frequencies, compressing the pulse. Fig. 3: Software to control the system, and data acquisition. FIBER BRAGG GRATING: RIPPLE MEASUREMENT: Fig. 4: Measurement with real time data presentation. SPECIFICATIONS: • Wavelength Bandwidth: 1520 nm – 1570 nm • Wavelength Resolution: 1 pm • Modulation Frequency: 300 k. Hz – 3 GHz • Spectral Resolution: 16 pm (1 GHz) • Group Delay Resolution: 0. 28 ps (1 GHz) Fig. 5: Add-on for quickly calculate Reflectivity or Group Delay ripple. either Fig. 7: Fiber with two gratings written. Fig. 6: Data analysis – Group delay ripple. Fig. 8: High resolution characterization for the second grating. CONCLUSIONS: A measurement setup was implemented for characterization of the amplitude and group delay parameters of Fiber Bragg Gratings. Efficient control of the setup with a user-friendly interface was achieved. Characterization of Fiber Bragg Gratings is carried out with high-resolution and fast processing. ADDITIONAL WORK: Fig. 8: Generic software for data acquisition from the Network Analyzer. ACKNOWLEDGEMENTS L. M. Ramos and R. P. Ramos would like to acknowledge Prof. A. Teixeira for his collaboration and are thankful for the grant conceded by the Program PRODEP III - Medida 3.