Interaction between ultrashort optical pulse and fibre gratings with random profile noise

Abstract

Optical pulses with a defined repetition rate have been used in modern dense wavelength division multiplexing systems, carrying phone calls, images, sound, video and other data. In the paper, the authors have investigated reflection of an ultrashort pulse from different types of uniform and Gaussian apodised gratings with random phase or amplitude noise. A symmetrical transform-limited 1 ps Gaussian pulse is assumed as the input, and the reflection spectra from different gratings with various noise levels are examined. Although the reflected pulses exhibit significantly different shapes, the authors present a qualitative explanation in order to find the physical insights and to understand the nature of the random profile noise effects when the ultrashort pulses interact with the fibre gratings. The results will be especially useful for potential applications such as a temporal pulse shaping, multi-wavelength source for an optical transmitter or OCDMA, where the random grating errors' impact on the ultrashort pulse reflection must be considered.