High Speed Single Mode Semiconductor Lasers Utilizing Coupled Ring Resonator Planar Geometry

We propose to develop a novel high speed, frequency controlled, single mode semiconductor laser based on planar ring resonator geometry. The technique utilizes electromagnetic fields interference effects within a coupled circular cavity to selectively shape the spectrum and determine the operating frequency of the laser. Unlike its counterpart distributed feedback (DFB) the ring resonator laser has no drive current limitations associated with spatial hole burning and non linear effects. Thus, high output power levels and wide tuning range, far in excess of DFB and other existing single mode lasers, are available. In addition, by incorporating a passive or active mode locking section into the cavity, we shall generate a high bit rate pulse train at frequencies exceeding 100 GHz. The ring resonator laser structure has clear advantages over linear Fabry Perot, DFB and DBR lasers. It is simpler to fabricate, cost effective, yet demonstrates a wide range of desired features, such as spectral purity, tunability, fast dynamics, and high output power. Since there is no need for cleaved mirrors or grating reflectors it can be integrated monolithically with other optoelectronic circuitry and subsystems.