共查询到20条相似文献,搜索用时 31 毫秒
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We present a polarization independent optical tunable filter (OTF) with nearly constant transmission characteristics over 1530-1570 nm. The tuning is achieved by horizontally sliding an interference filter, resulting in a very low polarization dependent loss (PDL)<0.1 dB and nearly constant characteristics over the tuning range. By cascading interference filters in double or triple stage, narrower bandwidth characteristics are obtained allowing for smaller channel spacing in wavelength division multiplexing (WDM) systems. Experimental results for PDL, loss, and bandwidth are presented and compared to those of angle-tuned filter. The proposed OTF has shown superior performance promising a practical solution for dense WDM applications. 相似文献
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Reports an inline angle-tuned Fabry-Perot etalon for optical channel selection in a high-density wavelength division multiplexed (WDM) direct-detection experiment. Feasibility is demonstrated in experiments with two different etalons: one for 5 distributed feedback (DFB) lasers in the 1550 nm region (1527-1559 nm), each spaced by 8 nm, and the other for 12 lasers (1527-1549 nm), each spaced by 2 nm 相似文献
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Maeda M.W. Patel J.S. Lin C. Horrobin J. Spicer R. 《Photonics Technology Letters, IEEE》1990,2(11):820-822
A 1.5-μm high-density wavelength-division-multiplexed (HD-WDM) system experiment is demonstrated using a novel Fabry-Perot etalon filter with a liquid-crystal electrical tuning element. The filter has a narrow passband (0.4 nm) and is continuously tunable over a wavelength range of >60 nm with a drive voltage from 1 to 5 V. Bit-error-rate measurements with an 8-channel (1539-1556 nm), 622 Mb/s WDM system confirms that the crosstalk penalty is negligible for an optical channel spacing of 2 nm 相似文献
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Weber J.-P. Stoltz B. Sano H. Dasler M. Oberg O. Waltz J. 《Lightwave Technology, Journal of》1996,14(12):2719-2735
After a review of the design principles, we present new experimental and theoretical results about the multigrating filter (MGF), a tunable channel selection filter for wavelength division multiplexed (WDM) transmission systems. Bit error rates mere measured at 2.5 Gb/s for single- and multichannel operation of a packaged polarization independent four-channel MGF with integrated amplifiers. The single-channel results are compared with theory. A monolithic tunable channel dropping component has also been fabricated by integrating two MGF's, a splitter, and amplifiers. Bit error rates measurements are presented for optical (at 2.5 Gb/s) and electrical on-chip (at 622 Mb/s) channel dropping in single- and multichannel operation 相似文献
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A dual-purpose, grating-based tunable optical filter/ring laser is described for accurate wavelength selection and generation at customer terminals. The device selects a single-wavelength channel from a HDWDM multiplex with 1 nm channel spacing, and simultaneously generates an identical wavelength as part of a tunable ring laser. The device is tunable over a 125 nm wavelength range, centered in the 1.5 μm low-loss fiber window 相似文献
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Applications are discussed for angle-tuned in-line Fabry-Perot etalons for optical channel selection in a high-density wavelength division multiplexed (WDM) direct-detection fiber system. A typical WDM application (LAMBDANET type) was described. Different demultiplexing techniques and their relative advantages were considered. Design guidelines are given for determining the etalon parameters, the minimum channel spacing and the maximum number of channels for a single etalon and multiple etalons, including stacked identical etalons and stacked nonidentical etalons. Experimental results on using these etalons for optical channel tuning in a multiwavelength WDM optical communication system are presented 相似文献
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G. Raybon U. Koren B.I. Miller M. Chien M.G. Young R.J. Capik K. Dreyer R.M. Derosier 《Photonics Technology Letters, IEEE》1997,9(1):40-42
Reconfigurable channel drop in a wavelength-division multiplexed system is demonstrated using a packaged semiconductor amplifier/filter. The filter is electrically tunable over 9.0 nm with a 0.9-nm width and is used with an optical circulator to demultiplex three 5.0-Gb/s WDM channels spaced by 2.25 nm. A receiver sensitivity improvement and low optical crosstalk is observed over a dynamic range of nearly 10 dB. 相似文献
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Iocco A. Limberger H.G. Salathe R.P. Everall L.A. Chisholm K.E. Williams J.A.R. Bennion I. 《Lightwave Technology, Journal of》1999,17(7):1217-1221
A Bragg grating fast tunable filter prototype working over a linear tuning range of 45 nm with a maximum tuning speed of 21 nm/ms has been realized. The tunable filter system is based on two piezoelectric stack actuators moving a mechanical device thus compressing an apodized fiber Bragg grating. The filter allows both traction and compression and can work in transmission and in reflection. It is designed to work with a channel spacing of 100 GHz according to the ITU specifications for wavelength division multiplexing systems 相似文献
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A new tunable optical notch filter for use in wavelength division multiplexing (WDM) transmission system has been fabricated in the InGaAsP/InP material system for use at 1.55 μm. The device uses tunable reflection gratings in a waveguide to control the channels (4 in this case). Crosstalk levels between 9 dB and 20 dB have been measured, depending on the channel. System experiments at 150 Mb/s show less than 1 dB crosstalk penalty at 10-9 bit-error rate 相似文献
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M.C. Parker R.J. Mears 《Photonics Technology Letters, IEEE》1996,8(8):1007-1008
A novel nonmechanical, digitally tunable, polarization insensitive and optically transparent wavelength filter using holograms electro-optically written on a ferroelectric liquid crystal (FLC) spatial light modulator (SLM) has been constructed and operated to tune to discrete wavelengths spaced by 1.3 nm. The filter has been incorporated in a ring laser which is tunable over a range of 38.5 nm across the erbium window, giving output powers of 10 mW. Both wavelength filter and tunable laser are suitable for wavelength division multiplexing (WDM) applications. 相似文献
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Two types of polymer thermo-optic wavelength tunable filter (TOWTF) have been developed, each with a pair of triangular phase shifters. One filter is designed for a large-scale WDM system (32 channels, 0.8 nm spacing), the other for a small-scale WDM system (10 channels, 0.8 nm spacing). The arrayed waveguide number is optimised thus reducing the operating power required by the filters. Moreover, both filters operated with a low crosstalk of <-25 dB 相似文献
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A novel tunable filter using a Fourier grating is studied and discussed. It consists of a Fourier grating, a collimator lens, single-mode fibers, and a computer controlled rotary actuator. It has very low polarization dependence of less than 0.3 dB, an insertion loss of less than 3 dB, and a narrow bandwidth of 1.5 nm. Wavelength selection was realized by rotating the grating, which was controlled by a computer. The device is able to select the light at the desired wavelength from more than 100 WDM optical data streams with 2 nm spacing in the range of 1.3-1.55 μm 相似文献
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为了实现高稳定性的可调谐激光输出,提出并设计了一种基于马赫-曾德(M-Z)结构和光纤光栅串结合的掺铒光纤激光器,在M-Z干涉结构的一个干涉臂中加入光学延迟线(ODL),实现对干涉间隔的灵活可调。系统结构设计采用976 nm波长的LD作为泵浦源,长度为6 m的掺铒光纤作为增益介质;采用光栅串将特定波长的光反射回环形腔形成振荡;采用M-Z结构产生梳状滤波用来对光栅串反射回的光进行选择;通过调节ODL来改变腔内损耗,进而实现激光的可调谐输出,并通过在系统中加入可饱和吸收体(SA)和子腔结构来抑制波长的跳变。实验中,在泵浦功率为100 mW时,实现了单波长双波长和三波长的稳定的激光输出。单波长共输出13个,调谐范围为1 570~1 596 nm,调谐间隔为2 nm,边模抑制比均大于50 dB。 相似文献
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K. Takada H. Yamada 《Photonics Technology Letters, IEEE》1996,8(5):658-660
An electrically-tunable narrow-band light source with no moving parts is constructed for jaggedness-free optical low coherence reflectometry. The source incorporates a double-path acoustooptic tunable bandpass filter module whose two passbands automatically agree to within 0.2 nm during wavelength tuning from 1529-1568 nm. The source emits narrow-band light with an FWHM of 1.8/spl plusmn/0.1 nm, a power of >0 dBm and a suppressed background spectrum. The entire wavelength range can be swept electrically within 100 ms by using a variable RF source. 相似文献
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Tunable optical filters for dense WDM networks 总被引:19,自引:0,他引:19
WDM is currently taking over as the leading technology in point-to-point transmission links. For optical implementation of WDM networks, logical functionalities such as wavelength (channel) selection should be carried out in the wavelength domain; thus, the development of dynamic optical devices is required. One key device is a tunable optical filter. Important features of such a filter include low insertion loss, narrow bandwidth, high sidelobe suppression, large dynamic range, fast tuning speed, a simple control mechanism, small size, and cost effectiveness. Here, an extensive overview of the different technologies used to produce tunable optical filters is presented. Among them, fiber filters such as fiber Bragg gratings and fiber Fabry Perot are the most commercialized, yet inherently limited in their dynamic speeds. For high demanding dynamics, micro-machined and acousto-optic filters can offer a good solution for microsecond tuning speeds. Faster tunable devices, in nanosecond tuning speeds, might emerge out of microresonators, electrooptic filters, and active DBR filters 相似文献
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J. Pfeiffer J. Peerlings R. Riemenschneider R. Genovese M. Aziz E. Goutain H. Künzel W. Grtz G. Bhm M. C. Amann P. Meißner H. L. Hartnagel 《Materials Science in Semiconductor Processing》2000,3(5-6)
In this work we report on micromechanically tunable Fabry–Pérot filter concepts for wavelength division multiplexing (WDM) systems. The optical resonator is designed for a cavity length around 30 μm in order to increase the filter selectivity while relaxing the demands on the required mirror reflectance. The introduction of micromechanical actuators, utilizing electrothermal and electrostatic principles, allows wavelength tuning of the filter over a range of more than 40 nm in the 1.55 μm wavelength regime. The movable Bragg mirror, designed as suspended membrane and fabricated with an InP bulk-micromachining technology, consists of a molecular beam epitaxy-grown InAlGaAs quarter-wavelength multilayer stack. The influence of micromechanical actuation and the effect of intrinsic mechanical stress on the mirror deformation has been investigated systematically to optimize the optical filter performance. Filter losses induced by the light absorption within the epitaxial Bragg mirror have been minimized using a highly doped InGaAs/InAlAs composition. Furthermore, low-loss Fabry–Pérot filters have been fabricated using InAlGaAs/InAlAs Bragg mirrors. The measured full-width at half-maximum (FWHM) is 0.24 nm and a filter insertion loss of 2.8 dB has been observed. The FWHM is kept below 0.35 nm over an entire tuning range of 40 nm for an actuation power of 1.3 mW. The bulk-micromachining technology presented here is open for the future development of WDM components, e.g. tunable receivers or laser diodes. 相似文献
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A widely tunable high precision chaotic fiber laser is proposed and experimentally demonstrated. A tunable fiber Bragg grating (TFBG) filter is used as a tuning element to determine the turning range from 1533 nm to 1558 nm with a linewidth of 0.5 nm at any wavelength. The wide tuning range is capable of supporting 32 wavelength-division mul- tiplexing (WDM) channels with 100 GHz channel spacing. All single wavelengths are found to be chaotic with 10 GHz bandwidth. The full width at half maximum (FWHM) of the chaotic correlation curve of the different wave- lengths is on a picosecond time scale, thereby offering millimeter spatial resolution in WDM detection. 相似文献
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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. 相似文献