根据大气光学湍流的光纤干涉测量技术原理及其信号表现形式,提出了一种基于希尔伯特(Hilbert)变换的动态相位差解调算法。数值模拟结果表明,该算法能够解调出波形相位差和符合湍流频谱特征的随机相位差,且绝对误差小于10-3,与相关法的解调结果一致。两者对比分析表明,Hilbert变换算法无需设定相关长度,对信号无平滑效应,因而能够更好地反映信号的频率特性。该研究为湍流随机相位差的检测提供了一个新方法。
A facile citric acid assisted sol-gel combustion method was performed to synthesize cobalt chromite (CoCr2O4) ceramic pigment. The effect of the annealing temperature on structure, morphologies, and optical properties of the prepared
作为固体激光器,自1961年由Snitzer Ε.发明玻璃激光器以来,已经经历了十几年,其间对钕激光玻璃的特性和质量进行了研究,现在,玻璃激光器已发展成为微微秒领域中的高功率激光器,是激光核聚变反应研究中不可缺少的最佳激光器,它与CO2激光器相并列登上了舞台。目前各个方面都在对这种器件进行着研究,以期将来能发展成为雷达和加工用可高重复振荡的小型激光器,以及眼科、牙科和治癌等的医用激光器。
The growth parameters affecting the deposition of self-assembled InAs quantum dots (QDs) on GaAs substrate by low-pressure metal-organic chemical vapor deposition (MOCVD) are reported. The low-density InAs QDs (~5×108 cm-2) are achieved using high growth
本文报导利用4.6微米附近谱线可调倍频CO2激光辐射的差值吸收对大气中的CO浓度进行单端遥测。CO的浓度根据地形目标所反向散射的激光回波推算,目标距离达2.5公里,浓度的总误差约为±10PPb。利用在不同距离、但在同一瞄准线上的几个目标,有可能进行假距离分辨测量,并能清楚地确定汽车道上CO浓度高度集中的地点。
Motivated by the achieved high intensities of novel extreme ultraviolet (XUV) radiation sources, such as free electron lasers and laser-driven high harmonic generation beamlines, we elaborate on their perspective in inducing observable strong field effect
A robust charge-coupled device (CCD) photoelectric autocollimator for outdoor use is designed and demonstrated. The influence of outdoor conditions on the signal-to-noise ratio (SNR) and imaging quality of the measuring system is experimentally analyzed.