The microring resonator (MRR) plays important roles in signal processing because high quality band-pass filtering can be obtained at its drop port. To promote signal to noise ratio, a high rejec

The microring resonator (MRR) plays important roles in signal processing because high quality band-pass filtering can be obtained at its drop port. To promote signal to noise ratio, a high rejection ratio is significantly demanded. However, it is still challenging to promote the rejection ratio of the MRR-based band-pass filter. To solve this problem, we propose to use an all-pass filter (APF) to enhance the rejection ratio of the MRR-based band-pass filter. Experimental results show that the improved rejection ratio is as high as 47.7 dB, which is improved by 23.6 dB compared with that of the MRR. Meanwhile, the bandwidth of the MRR-based band-pass filter is reduced from 2.61 to 1.14 GHz thanks to the constructive interference in the passband. Additionally, the center frequency of this ultra-high rejection MRR can be continuously tuned from 6.26 to 46.25 GHz. The quality(Q) of the MRR is improved from 7.4×104 to 1.7×105.During the adjustment, the rejection ratio of the band-pass filter remains exceeding 40 dB. The proposed approach can be used to achieve optical bandpass filters with high performance.show less

Spectroscopy, especially for plasma spectroscopy, provided a powerful platform for biological and material analysis with their elemental and molecular fingerprinting capability. AI has the treme

Spectroscopy, especially for plasma spectroscopy, provided a powerful platform for biological and material analysis with their elemental and molecular fingerprinting capability. AI has the tremendous potential to build a universal quantitative framework covering all branches of plasma spectroscopy based on its unmatched representation and generalization ability. Herein, we introduce an AI-based unified method called self-supervised image-spectrum twin information fusion detection (SISTIFD) to collect twin co-occurrence signals of the plasma and to intelligently predict the physical parameters for improving the performances of all plasma spectroscopic techniques. It can fuse the spectra and plasma images in synchronization, derive the plasma parameters and provide accurate results. The experiments demonstrates its excellent utility and capacity with 98% reduction in evaluation indexes and 143 Hz of analysis frequency. Besides, as a completely end-to-end and self-supervised framework, the SISTIFD enables automatic detection without manual preprocessing or intervention. With these advantages, it remarkably enhanced various plasma spectroscopic techniques with state-of-the-art performance and unsealed their possibility in industry, especially in the regions that require both capability and efficiency. This scheme brings new inspiration to the whole field of plasma spectroscopy, and enables in-situ analysis with a real-world scenario of high throughput, cross-interference, various analyte complexity, and diverse applications.show less

Proton acceleration in a near-critical-density gas driven by a light spring (LS) pulse with a helical structure in its intensity profile is investigated using three-dimensional particle-in-cell

Proton acceleration in a near-critical-density gas driven by a light spring (LS) pulse with a helical structure in its intensity profile is investigated using three-dimensional particle-in-cell simulations. Compared with other pulse modes with the same laser power, such as the Gaussian pulse or the donut Laguerre–Gaussian (LG) pulse, the LS structure significantly enhances the peak intensity and drives a stronger longitudinal acceleration field and transverse focusing field. Therefore, it is very promising to obtain ultrahigh-energy protons using LS pulses with a relatively lower power. For example, by using LS pulses with the same power of 4.81 PW, the proton in the gas can be accelerated up to 8.7 GeV, and the witness proton can be accelerated to 10.6 GeV from 0.11 GeV, which shows the overwhelming advantage over the Gaussian and LG pulse casesshow less

This article introduces a novel fiber-based picosecond burst-mode laser system capable of operating at high power and high repetition rates. A pulse-circulating fiber ring was developed as a bur

This article introduces a novel fiber-based picosecond burst-mode laser system capable of operating at high power and high repetition rates. A pulse-circulating fiber ring was developed as a burst generator, achieving an intra-burst repetition rate of 469 MHz without the need for a high-repetition-rate seed source. This design also allows for flexible adjustment of the number of sub-pulses, burst repetition rate, and burst shape. Additionally, a master oscillator power amplifier (MOPA) was employed to analyze the amplification characteristics of bursts. The system demonstrated a maximum average power of 606 W, with a measured sub-pulse duration of 62 ps and the highest sub-pulse peak power of 980 kW. To the best of our knowledge, this marks the highest average power obtained in burst-mode ultrafast lasers. Such a laser system holds potential for applications in precision manufacturing, high-speed imaging, high-precision ranging, and other diverse domains.show less