Multi-wavelength light source in 50GHz channel spacing using semiconductor optical amplifier

We propose a multi-wavelength fiber laser employing a double-pass Mach-Zehnder interferometer filter, a piece of polarization maintaining fiber, a semiconductor optical amplifier and an optical isolator. The proposed fiber laser has the advantages of stable multi-wavelength lasing with lasing wavelengths up to 33 channels in standard wavelength division multiplexing channel spacing of 0.4 nm using 15 m polarization maintaining fiber. Power variation among channels could be reduced by increasing the bias current of semiconductor optical amplifier.