Generation Of High-quality Millimeter-wave Based On Vcsels Subject To Optically Injection

The Radio-over-Fiber (RoF) is a communication technology which brings the agility of broadband wireless communication and the huge capacity of optical fiber communication together, it is a key technology in the design of the fourth-generation broadband communication system, which can offer an ideal solution for high-capacity, low-cost cable transmission of radio signals and more than1Gbit/s ultra-broadband wireless access. In Rof system, the technology of acquiring high-quality millimeter-wave subcarrier is critical. Presently, there are several ways of generating millimeter-wave, such as direct modulation, self-pulsations and mode-locked laser, optical heterodyne, optical phase-locked loop, dual-mode laser and optically injected semiconductor laser period-one state (P1) oscillation. The way of acquiring millimeter-wave based on optically injected semiconductor laser P1oscillation attract a lot of attention by related scholars.A scheme of optical generation of high-quality millimeter-wave based on the optically injected vertical-cavity surface-emitting lasers (VCSELs) PI oscillation is proposed in this paper. First the millimeter-wave based on the optically injected vertical-cavity surface-emitting lasers (VCSELs) P1oscillation has been studied, whose frequency can be continuously adjusted in a large range; then next the linewidth of millimeter-wave can be obviously narrowed by introducing polarization-rotated optical feedback. The results of numerical simulation show that under suitable operation conditions, a slave VCSEL (S-VCSEL) injected by a master VCSEL (M-VCSEL) will operate at the period-one (P1) oscillation state and the output optical intensity of S-VCSEL looks like being modulated by a microwave signal. By adjusting the injection strength and the frequency detuning between S-VCSEL and M-VCSEL, a millimeter-wave, whose frequency can be continuously adjusted in a large range, is obtained. After introducing polarization-rotated optical feedback, the linewidth of millimeter-wave can be obviously narrowed by adjusting the feedback strength and the feedback delay time. The results obtained in this paper are helpful to acquiring high-quality millimeter-wave used in high speed Radio-over-Fiber (RoF) system.