Author Affiliations
Abstract
1 Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China
2 Max Planck Institute for the Science of Light, 91058 Erlangen, Germany
3 e-mail: xiaozhuang235@163.com
4 e-mail: wdy@xjtu.edu.cn
In this study, we theoretically proposed a method to achieve an electromagnetically induced transparency (EIT)-like effect in a whispering gallery mode resonator (WGMR) and experimentally validated the method in a lithium niobate (LN) device. Benefitting from the electro-optic and inverse piezoelectric effects of the LN material, two modes of the LN WGMR that are close in frequency can be tuned at different tuning rates, resulting in EIT-like resonance lineshapes. By varying the electric field applied to the LN WGMR, the full dynamic of the EIT-like phenomenon can be precisely controlled. The experimental results agreed well with the calculations based on the coupled mode theory. Moreover, we observed a hysteresis resulting from the photorefractive effect of LN. We believe our proposed method and demonstrated devices offer a way to control an EIT-like effect, which could have potential applications in light storage, quantum information processing, and enhanced sensing techniques.
Photonics Research
2023, 11(5): 773
Author Affiliations
Abstract
1 School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
2 Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics (NUAA), Nanjing 210016, China
3 e-mail: pans@nuaa.edu.cn
We propose and demonstrate an agile X-band signal synthesizer with ultralow phase noise based on all-fiber-photonic techniques for radar applications. It shows phase noise of () at 10 kHz (100 kHz) offset frequency for 10 GHz carrier frequency with integrated RMS timing jitter between 7.6 and 9.1 fs (integration bandwidth: 10 Hz–10 MHz) for frequencies from 9 to 11 GHz. Its frequency switching time is evaluated to be 135 ns with a 135 pHz frequency tuning resolution. In addition, the X-band linear-frequency-modulated signal generated by the proposed synthesizer shows a good pulse compression ratio approximating the theoretical value. In addition to the ultrastable X-band signals, the proposed synthesizer can also provide 0–1 GHz ultralow-jitter clocks for analog-to-digital converters (ADC) and digital-to-analog converters (DAC) in radar systems and ultralow-jitter optical pulse trains for photonic ADC in photonic radar systems. The proposed X-band synthesizer shows great performance in phase stability, switching speed, and modulation capability with robustness and potential low cost, which is enabled by an all-fiber-photonics platform and can be a compelling technology suitable for future X-band radars.
Mode-locked lasers Microwaves Radar Fiber optics Ultrafast technology Photonics Research
2018, 6(1): 01000012
飞秒光梳为精密光谱测量领域带来了革命性的进展，不仅为射频与光频建立了直接的联系，将光谱测量精度提高至17 位，而且还可以直接用于光谱测量，产生了一门新的学科--直接光梳光谱学(DFCS)。在DFCS 中，光梳脉冲能量放大和非线性频率变换是不可或缺的手段，但是传统的脉冲放大、高次谐波产生过程会导致光梳的频率分辨率下降，精度和能量难以兼得。本文报道了激光光谱学中的重大进展--拉姆塞光梳光谱学，该技术结合了两个诺贝尔奖概念，可实现光谱的高准确度、高分辨率测量。
光谱学 拉姆塞 光梳 直接光梳光谱学 拉姆塞光梳光谱学 激光与光电子学进展
2015, 52(11): 113002
为了抑制偏振态漂移带来的功率变化给传输稳定度造成的影响,设计了一种能够快速补偿偏振变化的频率传输系统.该系统将锁模光作为光源,结合PID控制器反馈调节的原理,利用光功率放大器(EDFA)、起偏器、可变光功率衰减器(VOA)和单片机实现.实验结果表明:该系统能够有效抑制偏振态随着环境改变而发生的漂移,经过10 km传输之后的输出光功率稳定度达到1×10-5,与自由漂相比提高了200倍.将整个系统应用在光梳频率传输系统中,可以提高系统的鉴相精度,在5 GHz的传输频率上,可以有效消除偏振态变化引入的~50 fs的相位抖动.
偏振态 功率补偿 锁模光 PID控制 polarization state power compensation mode-locked laser PID control
为实现频率信号在长距离光纤上的高精度传输，设计了一个纯电的相位补偿系统，其补偿速度较快，范围较大，且便于模块化。该系统主要利用两次模拟移相抵消返回信号中所引入的双程相位抖动来进行补偿，结构简单，易于调试。通过引入数字信号处理和比例积分微分(PID)控制算法，可以提高系统的补偿精度和工作稳定性。最后，利用该系统在100 km 的实验室光纤上进行100 MHz 频率信号的传输实验，得到的频率稳定度为3.9×10-14/s 和1.1×10-16/4000 s，证明了此方法在长距离光纤频率传输中的可行性，为导航、航天以及空间探测等领域中远距离站点的协同工作，提供频率同步支持。
光纤光学 频率传输 相位抖动补偿 模拟移相 长距离
