基于AOTF的便携式近红外光谱测量仪

提出了一种新型的基于声光可调滤光器(AOTF)的便携式近红外光谱测量仪,该仪器可用于液态食品的组分浓度的测量.概述了声光可调滤光器的基本工作原理,并详细介绍了便携式近红外光谱仪的系统结构和组成.对一组成分含量已知的牛奶的光谱所建立的线性回归模型的分析表明,该模型具有良好的相关性,满足实际生产的需要.     

Toward the ideal codirectional Bragg filter with anacousto-optic-filter design

We present a novel design scheme based on the Gel'fand-Levitan-Marchenko inverse-scattering method for an acousto-optic tunable filter having an almost-ideal bandpass spectrum. We find that the ideal filter characteristics of flat-top with unity transmission and no side-lobes are in principle asymptotically possible in a properly designed codirectional Bragg filter. We propose physical schemes of achieving such characteristics in the acousto-optic tunable filter design. Filters having this desirable characteristic are of immense importance in improving the crosstalk performance in optical networks employing the wavelength-division-multiplexing scheme. We then discuss design specifics and simulated performances, and present a new optimization formula     

Gain equalization multiwavelength lightwave systems usingacoustooptic tunable filters

An acoustooptic tunable filter is used to compensate for the gain spectrum variations in multiwavelength lightwave systems containing cascaded fiber amplifiers. Demonstrations of such systems using a circulating loop containing a fiber amplifier and an acoustooptic tunable filter have shown that differential gain compensations of up to 14 dB can be achieved for two arbitrary injected wavelengths     

一种基于集成光学声光可调谐滤波器的近红外光谱仪

研制成功一种基于集成光学声光可调谐滤波器(IAOTF)的新型近红外光谱仪。从理论上分析了这种光谱仪的特征方程及分辨率，然后用三个中心波长不同的增益开关分布反馈激光器(DFB)的耦合光源进行了发射光谱的实验测量，最后通过傅里叶逆卷积的方法进行了光谱数据的恢复工作，从而进一步将该光谱仪的分辨本领提高到0．6nm。     

材料特性对声光可调滤波器光谱分辨率的影响

声光可调谐滤波器(AOTF)是一种利用各向异性介质中的声光作用工作的快速可调谐的分光元件,通过调节所加载的超声波频率可实现对出射光波长进行灵活、快速地调节.光谱分辨率是评价声光可调滤波器性能的主要指标之一.以二氧化碲非共线声光可调滤波器为研究对象,基于声光作用基本原理,系统推导了非共线声光可调滤波器光谱分辨率公式,并分...     

Wideband wavelength tunable modelocked fibre laser over 1557-1607nm

An electronically wavelength tunable modelocked fibre laser operating over a 50 nm range using an all-fibre acousto-optic tunable filter is presented. The tuning range is 1557-1607 nm, for a 70 m long erbium-doped fibre (EDF) with a 270 ppm concentration     

基于AOFT的便携式近红外光谱测量仪

文中提出了一个新型的基于声光可调滤光器(AOFF)的便携式近红外光谱测量仪，该仪器可用于液态食品的组分浓度的测量。文中概述了声光可调滤光器的基本工作原理，并详细介绍了便携式近红外光谱仪的系统结构和组成。对一组成分含量已知的牛奶的光谱所建立的线性回归模型的分析表明，该模型具有良好的相关性，满足实际生产的需要。     

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.     

TeO2晶体旋光性对其分光特性的影响分析

TeO2是声光可调滤波器主要成像晶体,由于晶体本身在分光成像时会产生色差,漂移等问题,文中从基础理论出发,研究了TeO2 晶体的旋光性对其作为声光可调滤波器时分光特性的影响,进而对其基本参数作了优化。首次对比分析了I.C.Chang理论体系与P.A.Gass修正理论体系,通过对比分析方法,得出在红外波段,两种理论体系对于超声波频率协调关系的计算结果差异较大,作者认为是I.C.Chang理论忽略晶体旋光特性所引起,因此,以P.A.Gass理论作为基础的声光可调滤波器设计方法适用于红外波段,当入射光极角小于30时,其旋光特性对分光性能的影响较小。通过对比分析可知,设计的入射光极角应小于54.7,这样可以保持较高的声光优值和较低水平的超声波频率;在红外波段,设计的入射光极角应小于39.2,两频率协调关系偏差f较小。     

Widely (132 nm) wavelength tunable laser using a semiconductor optical amplifier and an acousto-optic tunable filter

A widely wavelength tunable laser combining a semiconductor optical amplifier, an acousto-optic tunable filter and a Fabry-Perot etalon has been developed. It exhibited good characteristics over a 132 nm (1480-1612 nm) tuning range.     

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     

Tunable Acousto-Optic Filter for the 450–900 and 900–1700 nm Spectral Range

Journal of Communications Technology and Electronics - The problem of creating an acousto-optic (AO) tunable filter, which allows us to obtain high-quality spectral images both in the visible and...     

Simultaneous five-wavelength filtering at 2.2 nm wavelength separation using integrated-optic acousto-optic tunable filter with subcarrier detection

Demonstrates simultaneous, independent, five-wavelength filtering using an integrated-optic acousto-optic tunable filter with a wavelength separation of 2.2 nm. The worst-case power penalty is only 2.2 dB, demonstrating the feasibility of dense multiple-wavelength operation.<>     

1*2 polarisation-independent acousto-optic filter tunable over 1.30-1.56 mu m

A polarisation-independent, electronically tunable, acousto-optic filter made with commercially available components is demonstrated. It has a bandwidth (FWHM) of 4 nm, two complementary outputs, a fibre-to-fibre insertion loss of 6-8 dB, and is continuously tunable over 1.30-1.56 mu m. It is suitable for use in multiaccess WDM networks requiring approximately=microsecond-tuning time.<>     

集成光学声光光开关的研究

在集成光学声光可调谐滤波器的基础上，研制成一种偏振无关的集成光学波导型声光光开关，由于采用声光作用实现开关功能，使得开关速度可以达到微秒量级。介绍了这种集成光学波导型声光光开关的工作原理及其基本结构，并对它的插入损耗、隔离度、开关速度这三项光开关的重要性能指标进行了具体的理论分析与计算，然后对制作成的集成光学波导型声光光开关的器件样品进行了性能测试，在室内温度为20℃，入射波长为1．523μm时，测得插入损耗为4．8dB，隔离度为22．0dB。对实验与理论的误差进行了具体分析，并提出了进一步提高其性能指标的相关途径。     

Electronically tunable external-cavity semiconductor laser

The authors have demonstrated electronic tunability of 35 nm in an external cavity GaAs semiconductor laser by using an acousto-optic (AO) tunable filter and an AO modulator inside the cavity. Tuning is accomplished by varying only the drive frequency of the AO devices     

Experimental demonstration of multiwavelength optical network with microwave subcarriers

The authors use the unique multiwavelength filtering capability of the acousto-optic tunable filter to demonstrate multiple broadband services with only one fixed-wavelength transmitter and receiver per user in the first experimental demonstration of a multiwavelength subcarrier network.<>     

基于新型两级集成光学声光可调谐滤波器的环形腔掺铒光纤激光器

设计了一种以新型两级集成光学声光可调谐滤波器(IAOTF)为调谐元件的环形腔单偏振输出可调谐掺铒光纤激光器,它具有结构简单、调谐方便、调谐速度快和调谐范围大的优点。在对该集成光学声光可调谐滤波器滤波特性进行分析的基础上,在忽略放大的自发辐射(ASE)和激发态吸收情况下,对该激光器的特性参量如线宽、输出功率、斜率效率、阈值抽运功率等进行了分析。当抽运功率为100 mW,射频为175 MHz时,激光器输出中心波长为1550 nm,最大输出功率约6.34 mW,斜率效率为7.19%,半峰全宽(FWHM)为0.1 nm。当声波频率每改变0.1 MHz时,激光器输出中心波长改变约为0.88 nm,由于集成光学声光可调谐滤波器的滤波范围很大(当声波频率变化20 MHz时,滤波范围为180 nm),所以激光器的调谐范围仅取决于掺铒光纤的增益带宽。     

Time-dependent analysis of acousto-optic tunable filters formultichannel optical switching

A time-dependent analysis of acousto-optic tunable filters (AOTF's) for multiwavelength optical-switching operations is presented, it explains the reason for the observed nonlinear behavior such as passband-pulling and quantifies the associated crosstalk performance degradation. The degradation of the filter performance is found to be due to copresence of the acousto-optic interaction profiles for different channels. Along with extensive Poincare-sphere analysis, the model also reveals time-dependent fluctuation of switching spectral responses, which calls for attention to the worst instances in the fluctuation for the wavelength division multiplexer (WDM) optical-switch application     

Polarisation-independent low-power integrated acousto-optic tunable filter/switch using APE/Ti polarisation splitters on lithium niobate

A new polarisation-diversity integrated acousto-optic tunable filter/switch, incorporating passive Ti-indiffused waveguides and annealed proton-exchanged adiabatic X-junction polarisation splitters on XY lithium niobate, is demonstrated. The device requires only 11.2 dBm/channel of driving RF power. Switching characteristics at four 4 nm-spaced wavelengths are reported.<>