Frequency-modulated continuous-wave multiplexed gas sensingbased on optical frequency comb calibration

Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed gas sensing system basedon optical frequency comb (OFC) calibrated frequency-modulated continuous-wave (FMCW) tuning nonlinearity. Thesystem can be used for multi-parameter synchronous measurement of gas absorption spectrum and multiplexed opticalpath. Multi-channel parallel detection is realized by combining wavelength division multiplexing (WDM) and frequencydivision multiplexing (FDM) techniques. By introducing nonlinear optical crystals, broadband spectrum detection is simultaneouslyachieved over a bandwidth of hundreds of nanometers. An OFC with ultra-high frequency stability is used asthe frequency calibration source, which guarantees the measurement accuracy. The test samples involve H13C14N, C_(2)H_(2)and Rb vapor cells of varying densities and 5 parallel measurement experiments are designed. The results show that themeasurement accuracies of spectral absorption line and the optical path are 150 MHz and 20 m, respectively. The schemeoffers the advantages of multiplexed, multi-parameter, wide spectrum and high resolution detection, which can realize theidentification of multi-gas components and the high-precision inversion of absorption lines under different environments.The proposed sensor demonstrates great potential in the field of high-resolution absorption spectrum measurement for gassensing applications.

认罪认罚从宽背景下附条件不起诉的合理扩张

我国现行法律规定的附条件不起诉制度存在适用主体范围和罪名范围过窄、刑罚限制过严,以及决定主体与监督考察主体同一的弊端.以《刑法》为主体的犯罪网络越织越密,现行的附条件不起诉制度也越来越不适用.作为以审判为中心改革配套措施的认罪认罚从宽制度与附条件不起诉在作用发挥上具有同向性.应将附条件不起诉作为认罪认罚从宽制度中从宽的一种具体形式,扩大附条件不起诉适用主体和罪名的范围,降低刑罚限制,进一步发挥附条件不起诉的审前分流作用.另外将监督考察的工作交由社区矫正机构负责,使附条件不起诉的决定主体与监督考察主体相分离.

Reversible generation of dissipative Kerr solitons in a microresonator by the backward tuning method

Soliton generation schemes have attracted considerable scholarly attention.This paper introduces a novel backward tuning method for the reversible generation of dissipative Kerr solitons(DKSs).Reversible soliton generation relies on the thermal stabilization of the auxiliary laser,coupled with backward tuning of the pump laser,significantly increasing the range of soliton steps by over 10 times.Moreover,the method alleviates the stringent auxiliary laser detuning requirement.By adjusting the detuning of the auxiliary laser,diverse numbers of solitons can be deterministically generated,enhancing both flexibility and precision.

基于光学频率梳的高精度测距技术研究进展

精密测量技术是先进制造的重要支撑,其中精密激光测量技术在几何量测量特别是在线和高精度测量中应用最为广泛。针对先进制造更高的要求,新的激光测量技术不断发展,如基于光学频率梳的测距技术,其以宽光谱、窄脉宽、高频率稳定性的光频梳作为光源,通过相干探测可实现高精度和宽范围的绝对距离测量。同时,微纳制造工艺的提升以及光电子集成技术的发展,为进一步满足现场测量环境下高稳定性、仪器集成化和在线测量的需求提供了可能。围绕先进制造中高精度测距的需求,综述了光频梳测距方案的基本原理、性能指标与应用发展现状。首先,阐述了光学频率梳的基本特性和新型微腔孤子光频梳的相关研究;然后,详细介绍了光频梳频域、时域测距技术的测量原理和研究进展,包括色散干涉法、合成波长法、参考臂扫描法、重复频率扫描法和双光梳异步光学采样法等;最后,分析并比较了现有技术的发展进程及其优化方向,并对相关仪器化研制和现场应用进行了总结与展望。