Design of spectrum equalization filter for SLED light source

This paper considers the use of an all-fiber Mach–Zehnder interferometer (MZI) to equalize the output spectrum of a super-luminescent light emitted diode (SLED). A minimax approach and a window integration approach are proposed to design spectrum equalization filters with pre-specified performance indices. To present the proposed design approaches, a single stage MZI is used as an illustrative example to implement a spectrum equalization filter for the SLED. Both the simulation and the experimental results show that, with the obtained equalization filter, the output spectrum of the SLED can be equalized with 0.5 dB spectral flatness over a 65 nm spectral range. 2003 Elsevier B.V. All rights reserved.