title: Improving the performance of fiber gratings with sinusoidal chirps.
abstract: Sinusoidal chirps are introduced in fiber gratings to improve their performance as dispersion compensators and multichannel filters. The sinusoidally chirped fiber gratings exhibit a flattop spectrum with steep edges and high reflectivity. The bandwidth utilization defined as the ratio of -1:-30-dB bandwidth could be very high (>0.85). This structure can be applied to the sampled fiber gratings to enhance channel uniformity. We demonstrate 264 uniform channels with a 25-GHz-spacing for high-density-wavelength multiplexing applications. Multichannel dispersion compensations with seven uniform channels of 50-GHz-spacing in short fiber gratings are also demonstrated. The impact of possible fabrication errors on the spectra of the gratings is discussed.
authors.affiliation: Department of Precision Instruments, Tshinghua University, Beijing 100084, China. z-101@mails.tsinghua.edu.cn
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Changxi
authors.initials: C
authors.lastname: Yang