角度调谐滤光片的膜系优化设计算法

根据薄膜窄带滤光片在倾斜入射时的特性,通过改进间隔层膜系结构调整其等效折射率,可以设计出具有稳定透射峰值和带宽的角度调谐窄带滤光片.倾斜入射时窄带滤光片透射光的S和P偏振分量的中心波长会随着入射角度的增大出现分离现象,产生较大的偏振相关损耗.分析了偏振分离现象出现的原因和其与滤光片等效折射率的关系,提出了消除偏振分离现象的方法.根据薄膜矩阵理论建立了分析模型并提出了一种该可调滤光片的设计方法,根据开发的程序优化设计并制备了一组用于100 GHz密集波分复用(DWDM)系统的低偏振相关损耗的四腔角度调谐窄带滤光片,实验结果证明其满足设计要求并有接近20 nm的可调范围.     

基于薄膜滤光片的角度调谐系统设计

基于薄膜滤光片角度调谐的基本原理,实现了一种具有较宽波长调谐范围的可调窄带滤光器。通过优化机构装置参量,利用步进电机精确控制滤光片的入射角度。通过对多腔窄带薄膜滤光片的膜系结构及其等效折射率的计算,得到了滤光片透射中心波长与入射角度的关系式。制备了一个包括步进电机及转动机构在内的滤波器角度调谐装置,在1543-1563...     

改善蓝光特性的可调谐液晶滤光片

日本桃谷大学工程系 T.Uchida领导的研究组已开发一种利用向列液晶双折射特性的可调谐彩色滤光片。其透射波长可通过调节外加电压而连续改变。这种器件能从二维图像信息提取特定波长 ,可用于成像光谱仪。这种窄带彩色滤光片的结构基本上与双折射或Lyot滤光片相同 ,由夹在 4片偏振器之间的三片液　　电压控制可调谐滤光片 ,三片变带宽液晶池夹在偏振器之间。滤光片在 4 80～ 6 80 nm之间连续可调谐 ,在蓝光波长具有很高透射特性 ,P为偏振器 ,LC1～ 3 为液晶池晶池构成 (见图 )。液晶池是种电补偿弯曲 (ECB)池 ,把它放在电场中时其双折射…     

液晶法布里—珀罗调谐滤光片的研究

未来的光波分复用、频分复用系统将极大提高光纤传输系统的速度及容量,滤光片作为其中的关键部件,日益成为各国研究的热点.本文对利用液晶的电控双折射特性制成的以液晶为内腔物质的液晶法布里-珀罗调谐滤光片进行改进,在原来法布里-珀罗腔的两侧各加一偏振镜,使两个偏振镜的起偏方向平行,并且偏振方向都与液晶分子长轴的方向成45°角,这样入射光经多光束干涉后再经偏光干涉,可推出其透射光强为I=I0csin2(δj/2),其中δj=2π(n|-n⊥)d/λj,c为多光束干涉因子,这样改进后的液晶法布里-珀罗调谐滤光片便克服了原有调谐滤光片两套光谱难以区分的缺点.对改进后的以向列型液晶为腔内介质的法布里-珀罗调谐滤光片进行测试,得出在电压为1.6 V,频率为1 kHz的交流电压下,中心波长为1550 nm时,其半高全宽可达2 nm,自由波谱范围为7 nm,精细度为3.5.进一步的实验验证改进后的调谐滤光片随电压的变化(0～7 V)其调谐范围可达70 nm.(PD10)     

染料激光的双折射滤光片调谐

本文研究了闪光灯泵浦的染科激光器用双折射滤光片做波长选择元件的调谐过程以及影响调谐性能的因素,并对滤光片中晶片与玻片的合理安排进行了讨论.     

基于REC技术的可调谐激光器模块

通过重构-等效啁啾（REC）技术实现了一种基于分布式反馈（DFB）激光器矩阵的低成本可调谐激光器模块,对该模块进行了波长调谐、稳定性以及其他性能的测试,并将特定波长的参数加以标定。模块中的相邻激光器之间的中心波长间隔均匀等距且P-I特性良好,可调谐激光器输出波长的波动小于±3 pm,光功率变化小于0.02 dBm。波长调谐范围为1536.64～1559.36 nm,在该范围内依照ITU-T的DWDM标准涵盖了60特定波长通道,通道切换时间为5～30 s。     

基于全介质薄膜法布里珀罗滤光片的1550 nm可调谐外腔半导体激光器

提出并实现了一台基于单腔全介质薄膜法布里珀罗滤光片的1550 nm可调谐外腔半导体激光器。介绍了其内部的光学元件及其工作原理,随后对该半导体激光器的纵模输出特性进行了理论分析,搭建了该可调谐外腔半导体激光器。在不同的实验条件下,对该可调谐外腔半导体激光器在调谐过程中的输出波长、线宽及功率进行了实时同步测量。由所测数据总结出最佳实验条件,并得到了此条件下可调谐外腔半导体激光器的各相关参数。该可调谐外腔半导体激光器有一个线性的无跳模波长调谐区域(1547.203~1552.426)nm,一个稳定的输出光功率范围(40~50)μW,以及一个稳定的输出单纵模分布、线宽范围(100~150)MHz。该可调谐外腔半导体激光器可用于环境监测、原子与分子激光频谱研究、精确测量等领域。     

利用BF实现钛宝石激光器宽带可调谐激光输出

设计了一组双折射滤光片,由3片石英晶体组成,光轴倾角均为0°,基片厚度为0.45mm,3片厚度比为1:4:10.用于自行搭建的钛宝石激光器调谐实验,发现双折射滤光片绕其法线旋转约20°,输出激光中心波长可由760nm连续变化到845nm,并且线宽均小于2nm,最窄能达到0.73nm.泵浦能量465mJ时,800nm输出能量为85mJ.最大斜率效率为32.1%,最大光-光转换效率约为18.3%.双折射滤光片具有较好的调谐和压线宽作用.     

集成光学声光光通道监测仪的研究

在集成声光可调谐滤波器(IAOTF)的基础上,提出了一种新型的集成光学波导型声光光通道监测仪(OCM).介绍了该OCM的工作原理及其基本结构,对它的插入损耗、响应时间、波长范围、波长分辨率和波长精度等性能指标进行了分析与计算,并对制成的集成光学声光OCM进行了实验研究.理论分析和实验结果表明,该OCM能够对密集波分复用(DWDM)系统多路光信道的工作波长和功率同时进行监测,其插入损耗小于3 dB,响应时间小于7μs,波长监测范嗣达174 nm,波长分辨率可达0.3 nm、波长精度可达±30 pm.     

温控FBG式4通道波长可调准OADM研究

实现了一种带温度控制的基于FBG的4通道波长可调准光分插复用器(OADMs)。对用悬臂粱法调谐的FBG中心波长温度稳定性进行了研究,设计了一种灵巧的温度控制装置,解决了FBG中心波长可调谐和温度稳定性间的矛盾。测试结果表明,实现的OADMs在环境温度范围-20℃～ 60℃,中心波长变化小于0．004nm／℃,与未经温度补偿的悬臂梁调谐光栅相比温度稳定性提高了6．75倍。利用悬臂梁方法实现了FBC;中心波长的微调,调谐范围为1nm。4路OADMs的信道间隔为0．8m,上下路3dB通道带宽小于0．3nm,符合ITU-TG．692的要求。利用自制的FBG实现OADMs的邻道隔离度大于35dB。     

An adaptive wavelength tunable optical filter employing anangle-tuned interference filter and an intelligent digital controller

This paper describes an adaptive wavelength tunable optical filter, which is composed of an angle-tuned interference optical filter and an intelligent digital controller. The new angle-tuned interference filter consists of a dielectric interference optical filter and a piezoelectric angle-tuning mechanism. It achieves quick wavelength switching within 2.5 ms in a 30 nm tuning range and a sufficiently low crosstalk less than -30 dB. The intelligent digital controller has two functions: wavelength tracking and wavelength channel selection. Combining these technologies, we have developed a practical low-cost tunable filter suitable for a post-optical-amplifier filter in a high-sensitivity detection system and a channel selector in a WDM system that requires 10-100 ms channel selection time. With a wavelength tracking operation, we have confirmed -35 dBm high-sensitivity detection in 20 nm wavelength range in a 10 Gb/s system. We have also confirmed a wavelength channel selection operation within 18 ms in a three-channel wavelength division multiplexed (WDM) system whose channel spacing is 4.4 nm     

All-optical wavelength conversion using a pulse reformatting optical filter

We introduce a general concept for the design of all-optical wavelength converters with pulse reformatting functionality. The novel wavelength converters are based on a single semiconductor optical amplifier followed by an optical filter. A microelectromechanical system-based realization is shown and simultaneous 40 Gb/s wavelength conversion, switching and signal format conversion is demonstrated. The new pulse reformatting optical filter device outperforms current schemes with respect to input-power requirements, input-power dynamic range and signal quality.     

1.5 μm phase-shift-controlled distributed feedback wavelengthtunable optical filter

A 1.5-μm phase-shift-controlled distributed feedback wavelength tunable optical filter is studied. This wavelength tunable optical filter controls the transmissivity (gain) and the transmission wavelength independently by current injection. During wavelength tuning, the submode suppression ratio is large and a wavelength tuning range as wide as 120 GHz (9.5 Å) with 24.5-dB constant gain is achieved. An 18-channel wavelength selection with less than -10 dB crosstalk is expected with this filter. The effect of the light input, whose wavelength is in the sidelobe, on the transmission spectrum shape is shown     

1.5 μm phase-controlled distributed feedback wavelength tunableoptical filter

A 1.5-μm phase-controlled distributed feedback wavelength-tunable optical filter is studied. This is the first optical filter which controls the transmissivity (gain) and the transmission wavelength independently. Wavelength tuning range as wide as 43 GHz (3.4 Å) with high constant gain of 27 dB has been achieved. A five-channel wavelength selection with less than -10 dB crosstalk is expected with this filter. This device also operates as a wavelength tunable laser, and the wavelength tuning range as a laser is larger than as a filter. The reason is studied, and it is shown that suppression of the submodes is important to expand the wavelength tuning range     

1.5 μm two-section Fabry-Perot wavelength tunable optical filter

A 1.5 μm two-section Fabry-Perot wavelength tunable optical filter is studied. As opposed to DFB filters, this wavelength tunable optical filter has the advantage that the wavelength tuning range and the transmission bandwidth can be designed independently. This two-section Fabry-Perot filter also controls the transmissivity (gain) and the transmission wavelength independently by current injection and the constant-gain and constant-bandwidth wavelength tuning is achieved. The wavelength tuning range is as wide as 188 GHz (15 Å), the constant-gain is as high as 23 dB and the constant-bandwidth is as narrow as 5 GHz during wavelength tuning. A 25-channel wavelength selection with less than -10 dB crosstalk is expected with this filter     

Flexibly tunable microwave photonic FIR filter incorporating wavelength spacing programmable, arrayed micro-mirror based optical filter

A novel tunable microwave photonic FIR filter incorporating a wavelength spacing tunable multiwavelength filter based on a programmable arrayed micro-mirror device (AMMD) is demonstrated. Owing to the unique characteristic of the AMMD, that an arbitrary optical filter shape can be produced by defining a desired spatial pattern on an array of /spl sim/800 000 micro-mirrors, a wavelength spacing tunable multiwavelength optical filtering pattern is readily obtainable. By controlling the optical filter wavelength spacing, flexible resonance RF frequency tuning is achieved over a range of 2.3 GHz.     

基于温控的动态电磁可调谐级联光纤光栅滤波器

利用2个串联的完全相同的光纤布拉格光栅,研制了一种新型的中心波长可调谐的、宽带的单(双)信道滤波器。该滤波器采用电磁直接加纵向应力的调谐方式,同时利用半导体制冷器实现了对磁铁的温度控制。实验结果表明,该滤波器可以简单、灵活实现城域光网络中增、减信道的要求。     

入射角度不敏感型石英光双折射滤波器

为了实现石英光滤波器中心波长随角度变化不敏感的目的,利用石英光滤波器绕着平行于或垂直于石英光轴的方向旋转时,石英光滤波器输出中心波长漂移方向不同的原理,提出了一个新型的两级改进型的Lyot石英光滤波器滤波的方法,并进行了相关理论分析和实验验证。结果表明,当入射角小于18时,这个新型的光滤波器的中心输出波长的确对入射角度的变化不敏感。该结论与相关的实验结果是相符合的。     

Design and analysis of a novel tunable optical filter

In this paper, an improved design of a tunable optical filter device which is driven by a piezoelectric actuator is proposed. The device can be used either as a tunable optical filter for discrete wavelength alignment or as a dynamic optical filter. The tunable filter is electrostatically driven and consists of three main parts: The electromechanical stage, the suspension and the thin film optical filter. The electromechanical stage and the suspension were designed using graph presentation methods, studied numerically using the finite element method (FEM). The thin film optical filter was designed by a thin film design software. The electromechanical stage was integrated with the suspension and tested as an angular driver of thin-film tilt interference filter for dense-wavelength division demultiplexing system applications.     

A novel temperature-stable light-emitting diode

A new type of light-emitting diode (LED) has been developed, the light intensity of which is stable during temperature change. This device consists of a multilayer dielectric optical filter on the surface of a conventional LED. The transmissivity of the optical filter is low for the short wavelength region of the LED's light spectrum and high for the long wavelength region. When the LED's temperature increases, the spectrum of LED light shifts toward the long wavelength side because of the shrinkage of the energy gap of the compound semiconductor. The shift increases the total transmission of the light because the transmissivity is high for the long wavelength region. This increase compensates for the decrease of the LED light intensity, which is caused by the decrease of the internal quantum efficiency. The effect of this filter is confirmed by both calculation and experiment