基于中阶梯光栅的光谱定标装置设计方法

针对紫外-可见光波段高光谱成像仪光谱定标装置的设计进行研究,论述了中阶梯光栅的光学原理,根据光谱定标原理,利用中阶梯光栅工作角度大、衍射级次高、光谱分辨率高的优点,建立了基于中阶梯光栅的光谱定标装置,提出了基于中阶梯光栅的光谱成像仪光谱定标装置的设计方法。以大气探测卫星Aura 上所搭载的臭氧观测仪为例论述了光谱定标装置的设计过程,仿真分析了光谱定标装置带宽对光谱定标精度的影响,给出了衍射级次、光谱分辨率、平行光管焦距等光谱定标装置主要性能参数的设计计算方法,为基于中阶梯光栅的光谱成像仪光谱定标装置的设计提供了依据。     

阶梯光栅光谱响应校准方法研究

阐述了阶梯光栅光谱仪的工作原理和成像特征,分析了阶梯光栅光谱仪存在特殊光栅响应的原因以及给定量探测带来的影响.在此基础上,有针对性地提出一种基于标准灯的光栅响应的校准方法,校准后可以给出不同波长信号强度的真实分布关系,给光谱定量分析提供了现实依据.     

基于干涉条纹傅里叶分析技术对拼接光栅调整偏角的计算分析

阶梯光栅共相拼接技术是实现增大光栅尺寸、进一步提高天文光谱分辨率(天文光谱分辨率R>105)的关键。为了提高中阶梯拼接光栅的调整角度精度,本文基于干涉条纹傅里叶分析,提出了一种干涉条纹空间载频频率的九像素平均算法;然后结合干涉条纹光栅拼接技术,模拟了不同角度偏差下的条纹变化及其相应的傅里叶分析角度计算,在实验上实现了对系统角度调整系数的标定以及对傅里叶算法计算的调整偏角精度的分析,获得了拼接光栅调整系统中角度最大计算误差精度小于0.4μrad的结果,为天文上应用的大尺寸拼接光栅的共相调节提供了理论支持。     

光纤布拉格光栅传感器实现应力测量的最新进展

本文阐述了光纤布拉格光栅的特性及其在智能结构中的重要应用。针对这一应用 ,首先简要介绍了光纤布拉格光栅测量应力的原理 ,然后着重介绍了光纤布拉格光栅测量应力的最新进展。这些新的方法分别使光纤布拉格光栅在测量范围、测量精度、多路复用及实用性方面得到了提高或改进。光纤布拉格光栅要达到实际应用仍需对其作进一步的研究 ,以提高其工作寿命 ,找到简便易行的埋入方法 ,并实现信号的高精度、大动态范围的检测等。     

光纤布拉格光栅传感器的温度补偿研究

应力和温度变化引起光纤布拉格光栅(FBG)传感器中心波长漂移的交叉敏感效应制约了光纤布拉格光栅传感器的实用化。在简介光纤布拉格光栅传感器工作原理的基础上,综述了近年来国内外在该领域实现温度补偿的相关技术和消除或减弱传感器温度敏感的方法,阐述了光纤布拉格光栅传感器温度补偿的原理,并分析了每种方法的特点,探讨了光纤布拉格光栅传感器应用中存在的问题。     

长周期光纤光栅在色散补偿中的应用

通过与以往色散补偿器件的对比说明长周期光栅色散利、偿的优点,较详细地介绍了目前所研制出的两种长周期光栅(啁啾长周期光栅和高△的均匀长周期光栅)用于色散补偿的原理方法和在实际应用中需要解决的问题。     

Bragg光纤光栅

详细阐述了光纤光栅的原理以及光纤光栅在光纤通信、光纤激光器、光纤放大器、光纤滤波器、光纤传感器和高速光纤通信系统中色散补偿方面的重要应用，并对线性啁啾Ｂｒａｇｇ光栅色散补偿技术进行了全面分析。     

阶梯透射光栅衍射效率的研究

阐述了标量近似与Snell定律和Fresnel关系相结合的方法,并推导出阶梯透射光栅的衍射场强分布和衍射效率公式。以四阶梯透射光栅为例,详细分析计算了衍射效率及其影响因素。研究表明所得结果优于纯标量近似的结果。该方法避免了完全矢量波理论的麻烦,克服了标量近似的不足,特别适宜于研究周期大于4λ的光栅的衍射。对周期小于4λ的光栅,本方法的使用受到了限制。     

液晶光栅的技术进展及应用

详细阐述了液晶光栅的工作原理及两类液晶光栅的结构设计和制作工艺,分析了它们的优缺点及其应用情况。并对液晶光栅在空间光通信中的应用做了展望。     

光栅编码器介绍与应用

介绍了光栅编码器在精密机械方面的应用。从编码器的原理、技术参数和使用要点几个方面把光栅编码器的使用和优点呈现出来。通过具体的应用实现,去分析光栅编码器精度的提升,这对光栅编码器发挥最大效能有着重要的意义。     

Raman spectroscopic detection using a two-dimensional echelle spectrometer

In order to meet the high-resolution and wide spectrum range of the backscattering Raman system, this paper designs and builds a Raman test system based on the echelle spectrometer. In the optical splitting system, compared with the ordinary planar grating spectrometer, the use of the echelle improves the resolution of the system without increasing the volume of the system. The use of intensified charge-coupled device (ICCD) in the detection system improves the signal-to-noise ratio (SNR) and the detection limit of weak spectrum. Finally, the Raman system was spectrally calibrated. The broadband backscattering Raman experimental results are given and discussed. The experimental results show that the system has an excellent application prospect for broadband and high-resolution Raman spectrum measurement.     

Waveguide grating-based spectrometric transducers

A spectrometric transducer is a basic element of an optical measurement microsystem. This article explains the principle of operation of waveguide grating-based spectrometric transducers developed for telecommunication applications, their technological limits, and performance. These issues include optical loss (both total loss and the uniformity of loss as a function of channel number), crosstalk (both from adjacent or nearby channels and from those far away, called "background" in this article), polarization sensitivity (inherent in planar waveguide devices), and wavelength accuracy. The article also looks at commercialization issues such as long-term reliability, packaging, and cost. Even though the focus of this article is InP-based etched echelle grating demultiplexers, all of the lessons learned are independent both of the material system and the nature of the planar demultiplexer whether phasar or echelle grating.     

Monolithically integrated optical channel monitor for DWDM transmission systems

The design, fabrication, and performance of an InP-based monolithically integrated optical power monitor are presented. It contains 44 wavelength channels separated by 100 GHz and demonstrates record small footprint size. The device's major components, which include the echelle diffractive grating demultiplexer, passive waveguide circuitry and single-mode vertically integrated waveguide PIN photodetectors, are characterized and discussed as generic building blocks of InP-based planar lightwave technology for DWDM.     

Monolithic integrated wavelength demultiplexer based on a waveguideRowland circle grating in InGaAsP/lnP

We present detailed modeling and experimental results for an improved design of an InGaAsP-InP wavelength demultiplexer based on a monolithically integrated Rowland circle grating. The design incorporated ten wavelength channels at 1.55 μm with a uniform spacing of 2 nm. The total on-chip loss was about 10 dB and the crosstalk between adjacent channels was as low as -25 dB. It was shown that low-loss etched turning mirrors can reduce the total on-chip loss by about 4 dB compared to traditional 90° curved multimode waveguides. By replacing standard flat grating facets with retro-reflecting V-shaped facets in the echelle grating, the loss was further reduced by 4 dB. Polarization independent operation within a passband of 0.5 nm was achieved by using multimode output waveguides. The potential sources producing the crosstalk have been analyzed and fabrication modifications for further improvement are suggested     

Widely Tunable Grating Cavity Lasers

A widely tunable multi‐channel grating cavity laser is proposed and experimentally demonstrated. The device is implemented in Littman configuration with an echelle grating based on Rowland circle construction and realized by monolithically integrating all elements in an InP substrate. Lasing wavelength is selected by turning on an amplifier and the appropriate channel element in the array, and it is tuned by controlling light deflection electrically. The 6‐channel device exhibits a tuning range of about 50 nm with a side mode suppression ratio of more than 30 dB. This is accomplished by adjusting the applied current of the dispersive element and phase control section.     

Echelle grating demultiplexers with reduced return loss by using chirped diffraction order design

A design for echelle grating demultiplexers is presented to reduce the return loss. The input waveguide is placed on the minimal intensity position of the diffraction envelope. Then, by further chirping the diffraction order for each facet, we minimize the envelope intensity for other adjacent diffraction orders, which can contribute to a negligible return loss for a large spectral width. The present design is appropriate for multifrequency laser or multistage demultiplexer applications.     

Design and optimization of a novel InP-based monolithically integrated optical channel monitor

The design and optimization of a novel InP-based monolithically integrated optical channel monitor are presented. The device, which comprises a flat-field echelle grating and a slab photodetector array, can monitor signals in 40 wavelength channels separated by 100 GHz. The authors' simulations show that the novel design can result in a device of a smaller size and with a flatter and wider passband than those reported previously. It also features simpler fabrication without the need for output waveguides, thus eliminating issues related to fabrication-sensitive waveguide couplings. The shape of the slab waveguide detectors and the vertical layered structure are optimized to obtain a low crosstalk and a low polarization dependence.