西南交通大学信息科学与技术学院信息光子与通信研究中心，四川 成都 611756
传统基于频域-时域变换的微波光子解调技术应用于光纤布拉格光栅（FBG）传感网络时，为精确解调每一个FBG峰值，须确保对应时域响应信号不发生叠加，这对传感网络中FBG的空间间隔和波长间隔提出了严格要求，限制了微波光子解调技术的应用范围。针对存在的问题，将一种有效的元启发式算法，即算术优化算法（AOA），引入到基于频域-时域变换的微波光子解调技术中，实现了在时域信号叠加下对FBG的精确解调。实验构建了包含6个FBG的传感网络，通过对某一FBG施加轴向应变，验证了在时域信号部分叠加和完全叠加下AOA对FBG峰值解调的可行性。此外，与其他6种元启发式算法进行对比分析，验证了AOA在解调精度、解调速度与收敛效率等方面的性能优势。AOA提升了微波光子解调技术面向密集光纤布拉格光栅传感网络的解调能力。
微波光子解调技术 光纤布拉格光栅阵列 算术优化算法 光学学报
2023, 43(22): 2206002
Author Affiliations
Abstract
1 Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China
2 Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China
3 Center for Information Photonics and Communications, School of Information Science and Technology, Southwest Jiaotong University, Chengdu 611756, China
Temperature sensing is essential for human health monitoring. High-sensitivity () fiber sensors always require long interference paths and temperature-sensitive materials, leading to a long sensor and thus slow response (6–14 s). To date, it is still challenging for a fiber optic temperature sensor to have an ultrafast () response simultaneously with high sensitivity. Here, a side-polished single-mode/hollow/single-mode fiber (SP-SHSF) structure is proposed to meet the challenge by using the length-independent sensitivity of an anti-resonant reflecting optical waveguide mechanism. With a polydimethylsiloxane filled sub-nanoliter volume cavity in the SP-SHSF, the SP-SHSF exhibits a high temperature sensitivity of 4.223 nm/°C with a compact length of 1.6 mm, allowing an ultrafast response (16 ms) and fast recovery time (176 ms). The figure of merit (FOM), defined as the absolute ratio of sensitivity to response time, is proposed to assess the comprehensive performance of the sensor. The FOM of the proposed sensor reaches up to , which is more than two to three orders of magnitude higher than those of other temperature fiber optic sensors reported previously. Additionally, a three-month cycle test shows that the sensor is highly robust, with excellent reversibility and accuracy, allowing it to be incorporated with a wearable face mask for detecting temperature changes during human breathing. The high FOM and high stability of the proposed sensing fiber structure provide an excellent opportunity to develop both ultrafast and highly sensitive fiber optic sensors for wearable respiratory monitoring and contactless in vitro detection.
Photonics Research
2023, 11(8): 1397
1 西南交通大学物理科学与技术学院，成都 四川 610031
2 西南交通大学信息科学与技术学院，成都 四川 610031
常规数值求解方法在表征光纤中超短脉冲的非线性传输过程时存在计算量大、效率低等局限。随着人工智能的快速发展，深度学习技术展现出了强大的计算能力、广泛的适用范围、良好的硬件移植性，在光纤中超短脉冲非线性传输过程表征和控制研究中具有巨大潜力。本文概述了深度学习技术及其在预测光纤中超短脉冲传输、超短脉冲重构及参数估计方面的研究进展，同时展望了深度学习与光纤中超短脉冲非线性传输这一新兴交叉技术的发展方向和挑战。
光纤光学 超短激光脉冲传输 非线性薛定谔方程 光纤非线性效应 深度学习 中国激光
2023, 50(11): 1101011
1 西南交通大学物理科学与技术学院，成都 四川 610031
2 信号盲处理国家级重点实验室，成都 四川 610041
3 西南交通大学信息科学与技术学院，成都 四川 610031
全光纤超短脉冲啁啾放大技术在激光技术和超快光学领域备受关注。针对传统数值方法分析光纤中超短脉冲啁啾放大过程存在计算量大、效率低等问题，采用深度学习方法开展全光纤超短脉冲啁啾放大过程建模研究。首先分析脉冲啁啾参量等参数对超短光脉冲传输过程的影响。预训练设计的深度神经网络模型，分析网络对不同初始脉冲啁啾参量的预测精度，进一步探索了不同初始脉冲半峰全宽、峰值功率和啁啾参量等复杂情况下网络的泛化性及预测精度。本研究拓宽了数据驱动方法在激光行为预测方面的应用，为光纤中超短脉冲的特性研究提供了新思路。
非线性光学 光纤参量啁啾脉冲放大 卷积神经网络 非线性薛定谔方程
1 西南交通大学信息科学与技术学院，四川 成都 611756
2 上海交通大学区域光纤通信网与新型光通信系统国家重点实验室，上海 200240
提出并实验验证了一种基于硅基片上光路由的大规模光载一体化接收机多天线全球导航卫星信号（GNSS）差分定位系统。该系统基于光载无线（RoF）分布式天线架构实现远端多点GNSS信号采集，并利用低损耗、大带宽、抗电磁干扰的RoF传输链路实现远端采集GNSS信号的本地端集中式接收。在本地端处，利用互补金属氧化物半导体（CMOS）工艺兼容的高速硅基光开关芯片实现不同监测节点光载GNSS信号的定时切换与差分解算，构建基于片上光路由的时分复用型一体化接收机多天线GNSS定位系统。在实验中，利用自主研制的1×8马赫-曾德尔干涉型热光硅基光开关芯片构建了具有5个远端监测节点的多天线GNSS定位实验系统，GNSS信号的RoF传输距离为10 km。实验结果表明，该光开关芯片模块的实时响应时间小于200 μs，可在无需额外光放大的条件下稳定支撑10 km外5个远端监测节点的高精度定位，其在东（E）、北（N）、高（U）方向的定位精度均达到毫米量级。
光电子学 微波光子学 硅基光开关芯片 全球导航卫星系统 一体化接收机多天线 高精度定位 光学学报
2022, 42(24): 2425001
西南交通大学信息科学与技术学院信息光子与通信研究中心，四川 成都 611756
针对传统基于频域-时域变换的微波光子滤波解调技术应用于多点或准分布式传感系统时解调精度受限于射频（RF）响应测量带宽的问题，借助频谱细化算法选带快速傅里叶变换（Zoom-FFT）的思想，推导出时域细化表达式，有效解决了RF响应测量带宽、解调速率和解调精度三者之间相互制约的问题。相比于直接和补零离散傅里叶逆变换，在相同时域分辨率下，所提算法能大大降低对RF响应测量带宽的要求和频域-时域转换时的计算量，同时可有效提升解调速率。在验证性实验中，构建了包含5个光纤布拉格光栅（FBG）的多点传感系统，测试结果表明：在相同时域分辨率下，所提算法所需的计算点数减少为补零算法的1/200，运算时间降低为补零算法的10/145；对于给定的5 GHz扫频带宽，当采样点数大于1000点时即可实现亚皮秒级的时域分辨率，对应的FBG的波长解调精度为皮米量级。
光通信 微波光子滤波解调 时域细化算法 光纤光栅阵列 光学学报
2022, 42(23): 2306003
School of Information Science & Technology, Center for Information Photonics & Communications, Southwest Jiaotong University, Chengdu 610031, Sichuan , China
Exploiting microwave photonic (MWP) techniques to generate and distribute high-frequency millimeter-wave (mm-wave) signals, termed mm-wave radio over fiber (m-RoF) signals, holds considerable potential for achieving high-density and high-capacity fifth-generation and beyond networks. Herein, we experimentally validate a broadband m-RoF uplink fronthaul transmission system using the MWP downconversion concept, which comprises receiving and processing radio-frequency (RF) signals in the unlicensed V-band at around 60 GHz. The proposed system harnesses the simple cascaded modulator topology, in which an ultrawideband off-the-shelf Mach–Zehnder modulator (MZM) renders a simple-structured remote radio head by directly encoding the broadband 60 GHz uplink RF signal into the optical carrier. The nonlinear transfer function of another MZM at the center unit is explored to achieve subharmonic downconversion using cost-effective low-frequency local oscillator signals. Based on proof-of-concept experiments, mm-wave four quadrature amplitude modulation orthogonal frequency-division multiplexing signals centered at frequencies ranging from 51 GHz to 70 GHz are successfully downconverted into signals at the intermediate frequency (IF) of 1.4 GHz. In the case of 1.2 m mm-wave, free-space, and 5 km m-RoF transmissions, the obtained IF signals with a total bandwidth of 2.4 GHz achieve a bit-to-error ratio performance lower than the 7% hard-decision forward error correction limit of 3.8 × 10-3. A gross bit rate of 10 Gbit/s can be achieved over a total spectrum of up to 10 GHz, which fully covers the globally unlicensed V-band of 57-66 GHz.
激光与光电子学进展
2022, 59(13): 1336002
Author Affiliations
Abstract
1 State Key Lab of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2 Center for Information Photonics and Communications, School of Information Science and Technology, Southwest Jiao Tong University, Chengdu 611756, China
On-chip optical communications are growingly aiming at multimode operation together with mode-division multiplexing to further increase the transmission capacity. Optical switches, which are capable of optical signals switching at the nodes, play a key role in optical networks. We demonstrate a 2 × 2 electro-optic Mach–Zehnder interferometer-based mode- and polarization-selective switch fabricated by standard complementary metal–oxide–semiconductor process. An electro optic tuner based on a PN-doped junction in one of the Mach–Zehnder interferometer arms enables dynamic switching in 11 ns. For all the channels, the overall insertion losses and inter-modal crosstalk values are below 9.03 and –15.86 dB at 1550 nm, respectively.
Journal of Semiconductors
2022, 43(2): 022301
Author Affiliations
Abstract
1 Center for Information Photonics and Communications, School of Information Science and Technology, Southwest Jiaotong University, Chengdu 611756, China
2 International Cooperation Research Center of China: Communications & Sensor Networks for Modern Transportation, Chengdu 611756, China
This erratum corrects a clerical error in the original manuscript [
Photon. Res.9, 1124 (2021)PRHEIZ2327-912510.1364/PRJ.419605].
Photonics Research
2022, 10(2): 02000415
Author Affiliations
Abstract
1 Center for Information Photonics and Communications, School of Information Science and Technology, Southwest Jiaotong University, Chengdu 611756, China
2 State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
High-performance ultra-compact polarization splitter-rotators (PSRs) are designed and experimentally demonstrated, using dual etching and a tapered asymmetrical directional coupler. First, two novel PSRs are designed with nanowire and subwavelength grating cross-port waveguides and verified in simulations. Then, one of the two PSRs is fabricated. Experiment results reveal that the extinction ratio is higher than 28 dB or 32 dB at 1550 nm for the launched fundamental transverse magnetic or the transverse electric modes, while the corresponding insertion loss and polarization conversion loss are 0.33 dB and 0.18 dB, respectively.
polarization splitter and rotator silicon photonics asymmetrical directional coupler dual etching Chinese Optics Letters
2021, 19(12): 121301
