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1.
王运永  钱进  韩森  张齐元 《光学仪器》2015,37(4):371-376
引力波是爱因斯坦广义相对论的重要预言,引力波探测是当代物理学最重要的前沿领域之一。以引力波探测为基础的引力波天文学是一门新兴的交叉科学,是对传统电磁辐射天文学的巨大拓展与补充。作为一种大型的精密光学仪器并作为引力波天文学研究的关键设备,激光干涉仪引力波探测器已在世界各地蓬勃发展起来,开辟了引力波探测的新时代。给出了激光干涉仪引力波探侧器的工作原理和基本光学结构,讨论了主要的性能参数,分析了光学镜的结构特点及测量方法。  相似文献   

2.
为了研制出满足未来空间引力波探测需求的弱光探测器,初步进行了弱光探测器性能检测,分析了探测器的响应度、响应带宽、本底噪声等性能指标,以筛选出能满足未来空间引力波探测要求的探测器研制途径和解决方案。首先,根据空间引力波探测太极计划的激光器功率、轨道、星间距等设计方案,推算出太极计划所需探测器的性能指标;然后,与中国电子科技集团公司第四十四研究所、西南技术物理研究所和中国科学院上海技术物理研究所等单位合作研制了3款弱光探测器;最后,利用本课题组研制的低噪外差激光干涉系统对其响应度、响应带宽及本底噪声等指标进行检测,并分析了影响探测器性能指标的因素。实验结果表明:其中两款探测器的响应度优于1.8×105 V/W,响应带宽大于10MHz;3款探测器的本底噪声均低于10pm/Hz@10mHz(0.1mHz~1Hz),信噪比高于20dB。这3款探测器在响应度、响应带宽和信噪比等方面具有满足未来太极计划实验星要求的潜力。  相似文献   

3.
《光学仪器》2011,(2):37-37
<正>据英国《每日电讯报》4月18日(北京时间)报道,为在探测引力波这场竞赛中拔得头筹,欧洲万有引力天文台(EGO)正在建设全新的爱因斯坦望远镜,有望让科学家首次直接看到黑洞,并管窥宇宙诞生时的情景。阿尔伯特·爱因斯坦在《广义相对论》中首次提出引力波的概念。他认为万有引力是一种跟电磁波  相似文献   

4.
激光干涉引力波观察台(LIGO)是世界卓越的干涉型引力波探测设备。最初的LIGO探测器已经超出了设计的灵敏度,能够用来探测相距大约40 Mpc的双中子星的合并信号,探测信噪比等于8。当探测器还没被建造时,LIGO科研团队主要和Virgo团队合作,探究了大量天体物理学方面的上限。LIGO目前已经步入了先进探测的新领域,拥有升级版的先进LIGO干涉型探测器。LIGO实验室也和众多印度研究中心合作,在印度建立了一个先进的LIGO干涉仪。从而LIGO探测网络扩展了,拥有3个远距分散的干涉仪在单一网络中运行。  相似文献   

5.
激光干涉仪引力波观测器已经完成建设,该观测器称为高级LIGO或aLIGO,与2002—2010年间使用的引力波搜寻设备相比,预期灵敏度可以提高一个数量级。目前aLIGO的调试正在试运行。为了达到提升灵敏度的要求,探测器中的所有元件需要提升水平。在此将讨论光电调制器和法拉第隔离器在平均功率百万瓦级分离高质量光束能力的发展,并详述它们在aLIGO输入光学系统中的作用。  相似文献   

6.
2017年诺贝尔物理学奖授予了3位美国科学家雷纳—韦斯、巴里—巴里什和基普—索恩,以表彰他们对LIGO探测器以及引力波观测做出的决定性贡献。这是自1916年爱因斯坦利用广义相对论预言引力波的存在以来,人们首次直接在实验上观测到引力波的存在。这令人回忆起在1887年,德国物理学家赫兹首次用实验证明了电磁波的存在。引力和电磁力作为自然界的4种基本相互作用之一,其概念上有很多可以类比的地方。在本文中,我们将从物理的角度详细比较电磁波与引力波,有助于更好地区分这2种基本物理现象。  相似文献   

7.
《光学仪器》2006,28(5):17-17
“飞秒激光光学频率梳装置”(简称“飞秒光梳装置”)可用于对时间、频率和长度的超高精度测量,在导航定位、引力波探测、光通信等领域有着重要的作用。由中国计量科学研究院承担的科技部科技基础性工作专项基金项目“飞秒激光光学频率梳的研究”,9月12日通过了由国家质检总局组织的成果鉴定。  相似文献   

8.
激光干涉仪在引力波发现中起着关键作用,标准量子极限是干涉仪灵敏度进一步提高的主要障碍,压缩态光场注入是超越标准量子极限的重要手段。分析了压缩态光场的主要特点,讨论了压缩态光场的产生机制,介绍了压缩态光场技术在超越标准量子极限中的应用。  相似文献   

9.
《现代科学仪器》2012,(3):123-123
美国马里兰大学纳米物理和先进材料中心的研究人员开发出一种新型热电子辐射热测量计,这种红外光敏探测器能广泛应用于生化武器的远距离探测、机场安检扫描仪等安全成像技术领域,并促进对于宇宙结构  相似文献   

10.
王运永  钱进  韩森  张齐元 《光学仪器》2016,38(6):488-496
激光干涉仪在引力波发现中起着关键作用,光量子噪声是干涉仪灵敏度进一步提高的主要障碍。详细分析了光量子噪声中霰弹噪声和辐射压力噪声产生的机制和主要特点,讨论了标准量子极限,扼要介绍了信号循环、压缩光场等标准量子极限突破技术。  相似文献   

11.
In 2000 the first mirror suspensions to use a quasi-monolithic final stage were installed at the GEO600 detector site outside Hannover, pioneering the use of fused silica suspension fibers in long baseline interferometric detectors to reduce suspension thermal noise. Since that time, development of the production methods of fused silica fibers has continued. We present here a review of a novel CO(2) laser-based fiber pulling machine developed for the production of fused silica suspensions for the next generation of interferometric gravitational wave detectors and for use in experiments requiring low thermal noise suspensions. We discuss tolerances, strengths, and thermal noise performance requirements for the next generation of gravitational wave detectors. Measurements made on fibers produced using this machine show a 0.8% variation in vertical stiffness and 0.05% tolerance on length, with average strengths exceeding 4 GPa, and mechanical dissipation which meets the requirements for Advanced LIGO thermal noise performance.  相似文献   

12.
Detection of gravitational waves from astrophysical sources remains one of the most challenging problems faced by experimental physicists. A significant limit to the sensitivity of future long-baseline interferometric gravitational wave detectors is thermal displacement noise of the test mass mirrors and their suspensions. Suspension thermal noise results from mechanical dissipation in the fused silica suspension fibers suspending the test mass mirrors and is therefore an important noise source at operating frequencies between ~10 and 30 Hz. This dissipation occurs due to a combination of thermoelastic damping, surface and bulk losses. Its effects can be reduced by optimizing the thermoelastic and surface loss, and these parameters are a function of the cross sectional dimensions of the fiber along its length. This paper presents a new apparatus capable of high resolution measurements of the cross sectional dimensions of suspension fibers of both rectangular and circular cross section, suitable for use in advanced detector mirror suspensions.  相似文献   

13.
14.
Computerized ECG wave detection techniques have been evolving for the last three decades. Computerized ECG wave detection has been utilized in applications ranging from patient monitoring to computerized ambulatory arrhythmia detection. The most crucial part of any automatic ECG analysis is QRS detection. This review discusses adaptive and nonadaptive threshold techniques utilized in QRS detection. These techniques are suitable for software or hardware implementation. In addition, frequency domain and correlation methods for QRS detection are presented. In the summary a proposed QRS detection approach suitable for VLSI implementation is presented. This method has direct application to portable arrhythmia monitoring.  相似文献   

15.
Multi-oil droplet target recognition is one of the applications of machine vision in the measurement of oil-water two-phase flow parameters, which could combine other algorithms to obtain the oil droplet velocity and the water holdup of oil water two-phase flow. Appropriate target representation features can improve the recognition effect of multiple oil droplets. However, due to shooting environment differences and quality differences of oil-water two-phase flow images, existing target representation features do not perform well in low-quality oil-water two-phase flow images. To improve the precision of multi-oil droplet target recognition in oil-water two-phase flow and reduce the miss rate, this paper constructs an integrated feature on the basis of aggregate channel features (ACF). The integrated feature named aggregate channel features with histogram of local gravitational feature(ACFHG) contains the color feature channels reflecting the overall color features of the oil droplet sample, the gradient amplitude channel reflecting the overall gradient of the oil droplet sample image, the gradient direction histogram feature channels reflecting the local gradient of the oil droplet sample image, and the local gravitational feature channels that ensure oil droplet target recognition in low quality photos and photos taken in complex shooting environments. Moreover, the rotation invariance is obtained by taking the oriented gradient histogram of the local gravitational feature to further improve the multi-oil droplet target recognition effect. Experiment results show that the average precision of multi-oil droplet target recognition using the integrated features is 83.38%, which is 9.93% higher than that with using ACF, and the miss rate is 9.13%, which is 57.18% lower than that with using ACF. Compared with other existing target detection methods, the method proposed in this paper still has an advantage in the rate of missed detection.  相似文献   

16.
考虑重力影响的索结构损伤行波识别法   总被引:1,自引:0,他引:1  
王晓光  陆秋海 《机械强度》2003,25(6):609-613
因索中某几股断裂而导致索等效截面减小是索结构常见的损伤模式。文中分析此损伤模式下索受扰动后的行波响应,提出重力场中索结构损伤的行波识别法。该方法由索上一点的实测响应数据,根据入射波和反射波到达该点的时间确定损伤位置,根据入射波和反射波的信号能量比及能量的时域分布确定损伤程度和损伤段宽度。为适应现场有噪声测试数据的影响,应用多分辨率分析理论,以Daubechies小波分解行波响应信号,对信号去噪并作出白噪声情况下损伤识别方法的误差估计。仿真结果表明,该方法可采用噪声污染响应信号对重力场中索结构的损伤进行准确的估计,适合小损伤情况下索结构的损伤识别。  相似文献   

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