微波信号的光域产生是目前一个热门的研究课题, 在通信系统、信号处理、雷达等领域有着广泛应用。分别介绍了在微波光子学领域中基于连续射频调制和基于频率-时间映射技术生成特定光脉冲信号的频域合成法和时域合成法, 并对两种方法的几种具体方案进行详细介绍和对比, 从脉冲重复频率的调谐能力、脉冲占空比、脉冲类型、系统结构稳定性等方面分析其优缺点。
微波光子 光学函数波形产生 时域合成法 频域合成法 microwave photonics optical function waveform generation time domain synthesis frequency domain synthesis
利用光子学的技术来产生微波信号是目前一个热门的研究课题, 在通信系统、信号处理、雷达等领域有着广泛应用。主要介绍了利用光子学的技术来生成具有三角形时域特性的光脉冲信号的方法, 并对全光法以及包含频谱控制和时域叠加在内的电光法进行详细介绍和对比, 从脉冲重复频率的调谐能力、脉冲占空比、脉冲类型、系统结构稳定性等方面分析其优缺点。
微波光子 三角脉冲生成 全光法 电光法 microwave photonics triangular pulse generation all-optical method electro-optical method
Author Affiliations
Abstract
1 Key Lab of All Optical Network and Advanced Telecommunication Network of EMC, Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044, China
2 College of Physics and Engineering, Qufu Normal University, Qufu 273165, China
This Letter demonstrates a filterless v-band signals and pulses generator scheme with a tunable optical carrier to sideband ratio (OCSR). Through complete theoretical analysis, the mathematical expression of the OCSR that contains the extinction ratio, phase modulation index, and bias angle is obtained. It is found that the OCSR has a wide tuning range, from 50 to 70 dB. By careful adjustment, a 60 GHz millimeter-wave signal with the OCSR at 50.72 dB and the electrical spurious suppression ratio at 36.6 dB can be achieved. Moreover, the discussions of using optimum OCSR to generate a Nyquist pulse or triangular-shaped pulse are also presented in this Letter.
060.0060 Fiber optics and optical communications 060.5625 Radio frequency photonics 320.5550 Pulses Chinese Optics Letters
2017, 15(6): 060605
Author Affiliations
Abstract
Key Lab of All Optical Network & Advanced Telecommunication Network of EMC, Beijing Jiaotong University, Beijing 100044, China
A scheme of triangular-shaped pulses with full duty cycle generation is proposed and analyzed. Benefiting from the feature of orthogonal polarization, two approximate sinusoidal signals on different polarization states can be combined without inducing coherent interference. By tuning the time mismatching between the two signals, an approximately triangular-shaped profile can be obtained in the optical intensity. It is found that the modulation index β is no longer a fixed one, but it can be aligned within a proper range of 0.92 to 1.57. To evaluate the proposal, impacts of radio frequency voltage fluctuation, bias voltage drift, and time mismatching are discussed. Within the defined fitting error (η≤3%), the tolerable range of the modulation index, time mismatching, and voltage have been found, which insures a simple operation in practice.
060.1155 All-optical networks 060.5625 Radio frequency photonics Chinese Optics Letters
2017, 15(11): 110601
Author Affiliations
Abstract
Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044, China
A quasi-optical single-sideband (quasi-OSSB) modulation approach with a tunable carrier-to-sideband ratio (CSR) is proposed and demonstrated. By simply tuning the polarizing angle, a continuously tunable CSR can be obtained. Since the upper sideband is highly suppressed during the CSR’s tuning, quasi-OSSB modulation signals with extremely small interference are generated. An experiment is undertaken for verification. It is found that the target CSR can be continuously tuned over a wide range, which can be used to improve the receiver sensitivity of the fiber links.
060.0060 Fiber optics and optical communications 060.2360 Fiber optics links and subsystems 060.5625 Radio frequency photonics Chinese Optics Letters
2015, 13(8): 080606
提出一种多级高精度可调谐的瞬时频率测量(IFM)方法，采用单光源无滤波的IFM 系统结构，结合光偏振调制和偏振分束原理，利用偏振调制器和偏振控制器等器件来实现对同一波长下不同光偏振维度上微波信号的加载和分离。通过控制单模光纤的色散参数，可以获得较大的测量范围，利用色散所致的射频功率衰落效应，能获得单调变化的频率—幅度映射关系，进一步通过光电探测的射频信号输出功率比来得到幅度比较函数fACF。由于fACF 可以通过改变偏振角或直流偏置电压进行调节，因此该测量方法可用于多级频率测量实现对特定频率的高精度检测。结果表明，可以获得2~17.3 GHz的测量范围和±0.15 GHz的测量精度。
测量 调制 瞬时频率测量 测量范围 精度 中国激光
2015, 42(12): 1208005
三角形光脉冲在时域范围内具有前后沿恒定变化特性, 使得其在全光信息处理领域获得了广泛应用。主要针对目前国内外提出的两类三角形光脉冲产生方法: (1)电光法; (2)全光法, 简单介绍了几种具体的获得稳定三角形光脉冲串的方法, 从所产生三角形脉冲的重复频率、脉冲宽度以及系统稳定性、实验优缺点等方面进行分类比较, 并重点介绍了一种利用连续波光调制结合色散所致功率衰落的脉冲生成方法。
全光信号处理 三角形光脉冲 可调谐性 all-optical signal processing triangular optical pulse tunability
微波光子辅助的瞬时频率测量(IFM)系统具有高时间带宽积、低功率损耗、轻系统质量以及抗电磁干扰等巨大优势。对目前国内外研究的IFM系统按照频率-空间、频率-时间和频率-幅度三种映射方式进行分类介绍, 主要归纳比较了具有频率-幅度映射关系的IFM系统, 针对其中存在的测量范围和测量精度之间的互换(Trade-off)问题, 进一步引申到研究高精度可调谐测量范围的IFM技术, 并对目前相关领域的研究进行了追踪报道。
瞬时频率测量 微波光子 频率-幅度映射 instantaneous frequency measurement microwave photonic frequency-amplitude mapping
