In this simulation study, the dynamics of a twin vertical-cavity surface-emitting laser (VCSEL) subjected to optical injection are studied. A special novel configuration includes two laser devices, of which one is considered as the injector, while the other is considered as the transmitter. The signal for the first laser, LD1, is directed towards the second, LD2, which is responsible for chaotic transmission. During the signal trip from LD1 to LD2, the signal is separated into two parts by fibre Bragg grating (FBG). This is to change some signal properties. Results indicated that moderate bandwidth chaotic emission is available outside the laser device cavity. Contrary to conventional edgeemitting lasers, it is found that VCSELs operate with fewer modes and higher amplitudes. The selected properties for the simulated signal are: LD SEED, polarisation, FBG applied stress and temperature. The resulting lasing modes range from chaotic to enhanced modes. To ensure independent dynamics, cross-correlation (CC) between LD1 (which is responsible for perturbation) and LD2 antisynchronisation is approved. The CC for these two lasers ranged from −0.0028 to −6.5E−05.