Generation of microwave signals by active mode locking in a gain bandwidth restricted laser structure

Abstract
A simple method of generating microwave signals by using an active DFB InP-InGaAsP laser structure integrated with a passive extended cavity is presented. High spectral purity (<-94 dBc/Hz, 10 kHz offset) is achieved by locking the laser mode spacing to harmonics of an electrical drive signal applied to the laser bias current.