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基于外光注入VCSELs产生高性能毫米波
Generation of High-quality Millimeter-wave Based on Vcsels Subject to Optically Injection
【作者】 陈兴华；
【导师】 夏光琼；
【作者基本信息】 西南大学 ， 光学， 2012， 硕士
【摘要】 光载无线(RoF)技术是一种将宽带无线通信的灵活性与光纤通信的大容量传输的有机结合起来的通信技术,它是第四代宽带综合通信系统设计中的关键技术,可为大容量、低成本的无线电信号有线传输和超过1Gbit/s的超宽带无线接入提供理想的解决方案。在RoF系统中,高质量毫米波副载波的获取技术至关重要。目前,产生毫米波副载波的方法有直接电流调制、自脉动和锁模激光器、光外差、光锁相环、双模激光器以及光注入半导体激光器的单周期(P1)振荡等。其中,基于光注入半导体激光器的单周期(P1)振荡产生毫米波由于具有其独特的优势而受到相关学者的高度关注。本文提出了一种基于垂直腔表面发射激光器(VCSELs)的单周期振荡态获取高性能毫米波的方案。该方案首先基于外光注入VCSELs呈现的单周期振荡产生频率可调的高频毫米波,然后在此基础上通过引入偏振旋转光反馈,对毫米波的线宽进行窄化,从而获得高性能的毫米波。数值模拟结果显示：一个受到主VCSEL (M-VCSEL)光注入的副VCSEL(S-VCSEL)在一定条件下可以产生单周期(P1)振荡,即在光波上调制了一个微波信号。通过调节外光注入强度以及S-VCSEL与M-VCSEL之间频率失谐量,可以获得频率在大范围内连续可调的毫米波信号；进一步引入偏振旋转光反馈,在选取合适的反馈强度以及反馈延迟时间的条件下可使产生的毫米波信号线宽得到明显窄化。本文的研究结果对光载无线(RoF)系统中毫米波副载波信号的获取具有一定的参考意义。
【Abstract】 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.