Nitrogen-vacancy (NV) centers in diamond are progressively favored for room-temperature magnetic field measurement. The signal to noise ratio (SNR) optimization for NV diamond magnetometry generally concentrates on signal amplitude enhancement rather than efficient noise processing. Here, we report a compound filter system combining a wavelet denoising method and an adaptive filter for the realization of an efficient weak magnetic measurement with a high SNR. It allows enhanced magnetic field measurement with an average SNR enhancement of 17.80 dB at 50 nT within 500 mHz to 100 Hz and 14.76 dB at 500 mHz within 50 nT to 1100 nT. The introduction of this system in NV diamond magnetometry is aimed to improve signal quality by effectively eliminating the noise and retaining ideal signals.

悬浮光力传感技术利用真空环境的光阱实现对微纳尺度机械振子的悬浮和囚禁，将待测物理量转换为光悬浮机械振子运动参数的变化，理论上该振子与外部环境热噪声和振动完全隔绝，具有极高的测量分辨率潜力和易于小型化的独特优势。该技术在精密测量、微观热力学研究、暗物质观测、宏观量子态操控等领域具有广阔的应用前景。首先，阐述了悬浮光力系统中光力与光阱的基础概念和力学测量等基本理论；其次，介绍了其中初始起支、光力增强、位移测量、输出信号标定和等效反馈冷却等关键技术的研究进展，对比分析各子技术的特点，随后列举了悬浮光力传感技术在极弱力、加速度、微观质量、电学量、力矩等物理量测量中的典型应用；最后，总结了该技术的发展趋势，并提出相关建议。

金刚石中的氮-空位（NV）色心在室温下具有稳定的荧光发射，超长的电子自旋相干时间以及许多优良的光学性质，可以对电磁场，温度进行高灵敏度表征。光纤传感技术近几年来发展迅速，在电力、化工、交通、医疗、环保及**等领域得到广泛应用。光纤体系由于其集成度、实用性高以及操作便捷性，且具有优良的传输光能力，损耗较低，可与NV色心结合，形成一种高集成化、高灵敏度的便捷性传感系统，未来将会作为传感器件投入到许多领域的应用中，例如对生物细胞、材料温度、磁场等物理量的高灵敏度测量。本综述主要介绍NV色心体系的光纤量子传感技术的工作原理、实现方式以及在相关领域的应用。

Estimation of physical quantities is at the core of most scientific research, and the use of quantum devices promises to enhance its performances. In real scenarios, it is fundamental to consider that resources are limited, and Bayesian adaptive estimation represents a powerful approach to efficiently allocate, during the estimation process, all the available resources. However, this framework relies on the precise knowledge of the system model, retrieved with a fine calibration, with results that are often computationally and experimentally demanding. We introduce a model-free and deep-learning-based approach to efficiently implement realistic Bayesian quantum metrology tasks accomplishing all the relevant challenges, without relying on any a priori knowledge of the system. To overcome this need, a neural network is trained directly on experimental data to learn the multiparameter Bayesian update. Then the system is set at its optimal working point through feedback provided by a reinforcement learning algorithm trained to reconstruct and enhance experiment heuristics of the investigated quantum sensor. Notably, we prove experimentally the achievement of higher estimation performances than standard methods, demonstrating the strength of the combination of these two black-box algorithms on an integrated photonic circuit. Our work represents an important step toward fully artificial intelligence-based quantum metrology.

Nitrogen-vacancy color centers can perform highly sensitive and spatially resolved quantum measurements of physical quantities such as magnetic field, temperature, and pressure. Meanwhile, sensing so many variables at the same time often introduces additional noise, causing a reduced accuracy. Here, a dual-microwave time-division multiplexing protocol is used in conjunction with a lock-in amplifier in order to decouple temperature from the magnetic field and vice versa. In this protocol, dual-frequency driving and frequency modulation are used to measure the magnetic and temperature field simultaneously in real time. The sensitivity of our system is about 3.4nT/Hz and 1.3mK/Hz, respectively. Our detection protocol not only enables multifunctional quantum sensing, but also extends more practical applications.

为了研制出表面微透镜集成外腔的垂直腔面发射激光器（VCSEL），实现窄线宽无磁激光输出，满足原子磁强计等量子传感器应用要求，本文设计并生长了适合于表面集成微透镜的VCSEL外延结构，完成了表面微透镜集成外腔VCSEL器件制备，在电极材料方面选取无磁材料以满足应用要求。实验结果表明：研制的VCSEL器件工作温度达到90 °C，激光波长为896.3 nm，功率为1.52 mW，边模抑制比为36.3 dB，激光线宽为38 MHz，封装为模组后的磁场强度低于0.03 nT。结果表明本文研制的窄线宽无磁VCSEL满足量子传感的应用需求。

The nitrogen vacancy (NV) center in diamond has been well applied in quantum sensing of electromagnetic field and temperature, where the sensitivity can be enhanced by the number of NV centers. Here, we used electron beam irradiation to increase the generation rate of NV centers by nearly 22 times. We systematically studied the optical and electronic properties of the NV center as a function of an electron irradiation dose, where the detection sensitivity of magnetic fields was improved. With such samples with dense NV centers, a sub-pico-Tesla sensitivity in magnetic fields detection can be achieved with optimal controls and detections.