Wavelength division multiplexed (WDM) electroabsorption modulated laser fabricated by selective area growth MOVPE techniques

This paper describes the fabrication techniques pertaining to the on-wafer lasing wavelength control of an electroabsorption modulated laser (EML) using both a direct approach and a tunable wavelength source. The direct approach utilizes multiple grating pitches to control the on-wafer lasing wavelength of the DFB arrays. High resolution E-beam lithography was used to generate a phase mask to produce seven grating pitches separated by 0.25 nm pitch intervals. In a tunable wavelength sources approach, we used a multi-electrodes DFB lasers integrated with a bent waveguide for the wavelength tuning. These fabrication techniques show a promising low cost way of mass producing either set of discrete DFB devices with different wavelengths or a more complicated integrated device with wavelength combiner and a modulator.