微机在弱振动光干涉检测实验中的应用

介绍了利用微机在迈克耳孙干涉仪基础上进行微弱振动测量方法。     

Photon wave function formalism for analysis of Mach–Zehnder interferometer and sum-frequency generation

Biakynicki-Birula introduced a photon wave function similar to the matter wave function that satisfies the Schrödinger equation. Its second quantization form can be applied to investigate nonlinear optics at nearly full quantum level. In this paper, we applied the photon wave function formalism to analyze both linear optical processes in the well-known Mach–Zehnder interferometer and nonlinear optical processes for sum-frequency generation in dispersive and lossless medium. Results by photon wave function formalism agree with the well-established Maxwell treatments and existing experimental verifications.     

基于PA92的F-P扫描干涉仪设计

使用STM32F103ZET6单片机控制,采用PA92功率放大器驱动压电陶瓷,设计了532nm平平腔结构的F-P扫描干涉仪。腔镜反射率为99%,精细度310,腔长0.1~150mm连续可调,对应自由光谱区1~1500GHz和分辨率3.2~4800MHz连续可调。压电陶瓷驱动电压和频率通过编码器调节,可以在0~200V和1~100Hz连续可调,并显示在数码管上。同时可以通过RS232串口与计算机通讯,在上位机使用LabVIEW软件界面方便地设置压电陶瓷驱动电压和频率。使用F-P扫描干涉仪,对激光二极管泵浦Nd∶YVO4/KTP绿光激光器纵模进行了测量,验证了整个系统的工作性能稳定可靠。     

神光-III激光装置时标激光和任意反射面速度干涉仪探针光源产生技术

在惯性约束聚变研究中, 时标激光是对物理诊断数据进行分析的重要时间标尺, 而任意反射面速度干涉仪(VISAR)光源则是冲击波精密诊断必不可少的探针光源. 通过对物理需求的分析, 提出对时标激光与VISAR光源共用脉冲产生单元, 采用时分复用技术实现二者在同一台幅度调制器上的精密整形, 经1×2分束后再通过声光开关进行选择输出, 从而降低了系统造价, 便于集中控制. 采用了脉冲稳偏、高稳定空间放大、高精度温控谐波转换技术及可快速插拔精密复位的光纤耦合和传能技术, 实现了时标和VISAR光源脉冲的高稳定输出. 研制的时标激光系统可产生与主激光高精度同步的12路二倍频、4路三倍频时标信号, 为神光-III激光装置物理实验提供了重要的时间基准. 产生的VISAR光源脉冲在经过光纤系统和Nd: YAG棒状放大器后, 通过温控LBO晶体倍频, 然后经1 mm芯径的多模传能光纤传输至成像型VISAR系统, 为物理实验提供了单纵模、高亮度、可精密整形的脉冲激光. 系统已用于VISAR诊断物理实验, 获得了完整的冲击加载、减速的图像, 从而为冲击波调速及相关高压物理实验提供了可靠的技术手段.     

双S型光纤结构的传感特性

在剥除涂覆层的单模光纤上熔成两个间距为25mm的S型结构,构成双S型全光纤马赫-曾德干涉仪.入射光经过第一个S型结构时部分光被激发到包层,经过第二个S型结构时重新进入纤芯传播,S型结构中光纤的纤芯模和包层模耦合产生干涉.利用干涉光谱测量外界因素的响应并用于温度、折射率和微位移的测量.实验结果表明,温度、折射率和微位移的灵敏度分别为69pm/℃,132.64nm/RIU,-178pm/μm,且具有很好的线性度.该传感结构为全光纤结构,制作简单,易于实现且成本低.     

迈克尔逊干涉仪实验中最佳间隔条纹个数的探讨

用迈克尔逊干涉仪可以测量激光的波长,读取的干涉条纹个数较多时容易引起学生视力的疲劳。因此,本文测量了多组不同的间隔条纹个数时氦氖激光的波长,进而确定它们与波长理论值之间的误差大小,通过比较不同间隔条纹个数时百分差和相对不确定度的大小,最终确定最佳的间隔条纹个数。     

Femtosecond time-resolved two-photon photoemission studies of electron dynamics in metals

Electron-hole excitation and relaxation in the bulk, at interfaces, and surfaces of solid state materials play a key role in a variety of physical and chemical phenomena that are important for surface photochemistry, particle-surface interactions, and device physics. Information on charge carrier relaxation in metals can be obtained through analysis of linewidths measured by photoemission and related techniques, which give an estimate of the upper limit for electron and hole relaxation; however, many factors can contribute to spectral broadening, thus it is difficult to extract specific information on electronic relaxation processes. With femtosecond lasers it is possible to probe directly in a time-resolved fashion the charge carrier dynamics in metals by a variety of linear and nonlinear optical techniques. Femtosecond time-resolved two-photon photoemission has attracted particularly strong interest because it incorporates many of the surface analytical capabilities of photoemission and inverse photoemission — the traditional probes for surface and bulk band structures of solid state materials — with time-resolution that is approaching the fundamental response of electrons to optical excitation. Advances in the direct measurements of electron-hole excitation, charge carrier relaxation, and dynamics of intrinsic and adsorbate induced surface states are reviewed. With femtosecond lasers it also is possible to probe a variety of coherent phenomena, and even to control the charge carrier dynamics in metals through the optical phase of the excitation light. Pioneering experiments in this new field also are discussed.     

Submillimeter laser interferometer for high density plasma diagnostic

There are presented the results of investigation of the one-channel homodyne laser interferometer =119 µm made on the basis of the hollow dielectric beamguide and quasioptical functional devices. The interferometer is designed for determination of the plasma electron density of the TOKAMAK-7. The density response threshold is 0.7% from the expected plasma density and the phase difference measurement total error is 5°     

双光路干涉测量的控制系统设计

传统的大口径光学元件干涉测量方法依赖于根据不同测试样品人为改变扩束镜头和光路结构,该方法会不可避免引入一些系统误差,因此针对双光路干涉仪的功能需要和仿真实验,提出了一套对应的双线控制方案。通过蓝牙通信、串口通信和机械结构的相互配合可以对光路进行多次折转和校准,使得每次切换测量口径后的光学元件变化位置固定,并在基于MFC(microsoft foundation classes)开发的交互界面显示实时状态。结果表明：在450 mm测量口径下,PV10测量重复性可达到0.004λ,RMS测量重复性可达到0.000 4λ;在100 mm测量口径下,PV10测量重复性可达到0.000 8λ,RMS测量重复性可达到0.000 16λ。实验结果表明该系统保障了优越的测量效率和测量重复性,为双光路干涉仪的研发提供了参考价值。