Wavelength bistability based on optical injection in a novel tunable dual mode laser.

A novel tunable dual mode laser is proposed based on a double-layer Bragg grating structure, named double-layer grating distributed Bragg reflector (DLG-DBR) laser. With controlling the gain saturation condition, different oscillating states can be observed. The nonlinear dynamics characteristics including bifurcation of the laser under optical injection with two different start-up sequences are analyzed with numerical simulations. Furthermore, we investigate the lasing wavelength bistability of the laser combined with its tuning characteristics theoretically. Optical memory operation based on the external optical injection locking bistability of the dual mode device is proposed. The memory operation can be achieved in the whole wavelength window with a 10 nm tuning range. A mode suppression ratio (MSR) of more than 45 dB is achieved between the two bistable states.