共查询到20条相似文献,搜索用时 553 毫秒
1.
In this work, an advanced multifunctional optical switch based on multimode fibers is proposed. It can work as a 3 × 1 optical multiplexer/combiner, a 2 × 2 optical switch, a variable optical attenuator and a variable optical power splitter. All these functionalities can be developed in the same device without any hardware modification, only by using the proper ports and control electronics.The proposed switch has been developed for being used in the visible and near infrared wavelength range: 450–650 nm for optical fiber automobile applications, 650–850 nm for home broadband applications; and 850–1300 nm for multimode fiber access networks. Up to three different types of twisted nematic liquid crystal cells have been designed and fabricated for fulfilling these different wavelength ranges as part of the proposed device.The multifunctional switch has been implemented and experimentally tested. Crosstalk usually better than ? 15 dB at 532 nm, 660 nm and 850 nm, in any state has been measured. Switching is achieved at voltage levels of 4 Vrms. Fiber to fiber insertion losses when operating as a 2 × 2 optical switch, range from 10 to 15 dB within 200 nm wavelength range; with a non-optimized optics for collimation and coupling. 相似文献
2.
Yongsheng Zhang Hui Ma Tao Zhang Zhuo Wang Dong Wang Rongsheng Zheng Haipeng Yang Hai Ming 《中国光学快报(英文版)》2005,3(10)
Visible light wavelength division multiplexing (VWDM) experiment was performed using polymer optical fiber (POF). Lights of two different wavelengths (650 and 530 nm) were sent to a single POF. Red light (650 nm) was used for 100-Mb/s full duplex IP data transmission and green light (530 nm) was used for voice signal transmission. Light sources are light-emitting diodes (LEDs). A POF coupler (splitter) and the prisms were employed as multiplexer and demultiplexer, respectively. The channel isolation and insert loss were measured, which are 20.5 and 17.65 dB for 650-nm channel respectively, and 19.16 and 20.55 dB for 530 nm one respectively. 相似文献
3.
We design and model a highly compact and tunable optical add-drop multiplexer (OADM) device that consists of long-period gratings and piezoelectric ceramic fiber stretchers. The proposed OADM shows that 50 dense wavelength-division multiplexing channel signals can be selected in the wavelength range from 1526.25 to 1563.75 nm with 0.75-nm channel spacing, which covers the whole C-band gain spectrum of an erbium-doped fiber amplifier. The cross talk between channels is less than -39 dB, and the total insertion loss of the device is approximately 0.24 dB, which includes the splicing losses, the mode mismatching loss, and the expected losses in the two side-by-side coupled fibers. 相似文献
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5.
Peng-Chun Peng Ching-Hung Chang Hai-Han Lu Yi-Tzai Lin Jen-Wei Sun Chang-Han Jiang 《Optics Communications》2012,285(13-14):3093-3099
Two novel optical add-drop multiplexer (OADM) with different self-healing functionalities for reliable wavelength-division-multiplexing networks are presented and demonstrated. Single or multiple failure-link traffics can be bi-directionally restored without the need for wavelength conversion or extra backup fiber links. To evaluate the performances of the proposed structures, a 77-channel CATV signal is experimentally transmitted with a favorable carrier-to-noise ratio (CNR), composite second-order (CSO) and composite triple beat (CTB) performances. 相似文献
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In this paper, two stage hybrid optical amplifier (HOA) composed of a single erbium doped fiber amplifier and Raman amplifier is proposed for dense wavelength division multiplexed (DWDM) system and investigate the impact of reduced channel spacing. The performance has been evaluated in the term of gain, gain flatness and noise figure. Also, using gain equalization technique, hybrid optical amplifier that has a gain flatness of 3 dB, and a noise figure of less than 7.4 dB is observed. 相似文献
8.
A hollow-core microstructured polymer optical fiber is fabricated from polycarbonate material and guidance by inhibited coupling in a two-layer structure is demonstrated in two strong transmission bands with minimum losses of 9.0 dB/m at 800 nm and 3.1 dB/m at 1550 nm. The latter corresponds to a loss well below the polycarbonate material loss at this wavelength, and to our knowledge it is the lowest loss hollow-core polymer fiber reported to date. The short-term operational temperature limit of the fiber is shown to be 135 degrees C, significantly higher than that of conventional polymer optical fibers made of other polymers. 相似文献
9.
In this paper, we propose a full-bandwidth reconfigurable optical add/drop multiplexer (ROADM) equipped with multiplexer/demultiplexer (MUX/DEMUX) and switch array. Based on the pairwise multimode interference (MMI) and side-ported MMI, the full-bandwidth MUX/DEMUX is achieved. The switch array based on microring resonators (MRRs) can achieve the function of the wavelength selective switches. By designing the second-order series-coupled MRR structure, using thermo-optic effect, the switch is able to get a switching ratio above 16 dB. The proposed ROADM system shows good performance for application in dynamic optical networks. 相似文献
10.
Michel E. Marhic Peter A. Andrekson Periklis Petropoulos Stojan Radic Christophe Peucheret Mahmoud Jazayerifar 《Laser \u0026amp; Photonics Reviews》2015,9(1):50-74
The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase‐insensitive amplifiers (PIAs) and phase‐sensitive amplifiers (PSAs) are considered. Low‐penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength‐ and time‐division multiplexed formats. High‐quality mid‐span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All‐optical amplitude regeneration of amplitude‐modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase‐modulated signals. A PSA with 1.1‐dB noise figure has been demonstrated, and preliminary wavelength‐division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength‐division multiplexed long‐haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long‐haul communication networks are discussed.
11.
A novel monitoring method for in-service fault indemnification in passive optical networks (PONs) is proposed and demonstrated experimentally. The proposed monitoring technique is based on fiber Bragg grating (FBG) sensors and fiber laser scheme, and a semiconductor optical amplifier (SOA) is used to serve as a gain medium. By detecting the number of the wavelength lasing, the fiber-fault can be monitored without affecting the in-service channels. Moreover, the strain behavior on the FBGs has also been discussed. 相似文献
12.
提出了一种新型的基于波长双环路结构的光电振荡器方案. 在此方案中, 利用两个激光器产生两束波长不同的连续光, 分别通过两段长度不同的光纤构成双环路结构, 利用光学游标效应可以获得单一的起振模式. 通过理论分析可知, 不同波长的两束光载波在耦合时, 几乎不会产生随机拍噪声. 实验中, 获得了X波段(8-12 GHz)内频率可调谐的高质量微波信号. 通过测量, 信号的边模抑制比达到60 dB, 相位噪声为-132.6 dBc/Hz@10 kHz. 同时, 利用锁相环技术, 通过光纤拉伸器有效补偿系统的腔长漂移, 因此振荡频率的稳定性得到极大改善. 系统的频率漂移在2 h内小于±84.3 mHz. 另外, 测得的微波线宽为5.3 mHz, Q值在1012量级, 具有很高的谱纯度. 相似文献
13.
An optical fiber multi-function device consisting of a single gradient-index-rod lens and a multi-facet blazed reflection
grating is proposed to simultaneously realize functions of wavelength demultiplexing and optical signal distribution in a
multimode optical fiber transmission system. We analyzed the demultiplexing characteristics and the tolerance of optical components
using the ray trace method. This device can realize not only low loss optical signal distribution but also offers improved
demultiplexing characteristics in comparison with the previously proposed demultiplexer-multiposition switch. The following
characteristics are expected from the design using commercially available optical components: a working band of 0.64–0.88
μm, channel separation of 34–36 nm, 3 dB bandwidth of 27–28 nm, channel cross-talk of less than - 40 dB and minimum excess
insertion loss of 0.9–2.1 dB. 相似文献
14.
Zhi-Ming Liu Jian Li Peng Liu Jing-Jing Zheng Lin-Yong Fan Shui-Sheng Jian 《Optics & Laser Technology》2010,42(8):1261-1265
A simple and effective switchable dual-wavelength polarization-maintaining erbium-doped fiber laser is proposed and demonstrated. Only using a uniform fiber Bragg grating written directly in a segment of the photosensitive and polarization-maintaining erbium-doped fiber as the wavelength selector and an optical circulator as the all-reflecting mirror, a stable simultaneous dual-wavelength oscillation is achieved with a wavelength spacing of 0.364 nm experimentally by exploiting the polarization hole burning effect at room temperature. The output can be switched between single- and dual-wavelength by adjusting the polarization controller. The 3-dB bandwidth and the side mode suppression ratio of the laser’s outputs are measured to be less than 0.01 nm and more than 50 dB. The power fluctuation and wavelength drift are measured to be less than 0.50 dB and 0.020 nm over an hour. 相似文献
15.
We propose a new system of a continuous variable quantum key distribution via a wavelength router in the optical networks. A large bandwidth signal is generated by a soliton pulse propagating within the micro ring resonator, which is allowed to form the continuous wavelength with large tunable channel capacity. There are two forms of localized soliton pulses proposed. Firstly, the required information is transmitted via the localized temporal soliton pulse. Secondly, the continuous variable quantum key distribution is formed by using the localized spatial soliton pulse via a quantum router and networks, which is formed by using and optical add/drop multiplexer incorporating in the network. The localized soliton pulses are available for add/drop signals to/from the optical network, where the high security and capacity information can be performed. 相似文献
16.
A bandwidth-tunable optical passband filter with tunable attenuation is proposed. The filter, composed of a transmission liquid crystal array and high-resolution diffraction grating, was successfully demonstrated based on the compact spatial light design. Experimental results showed that the bandwidth, wavelength, and attenuation could be tuned by controlling the voltage applied on the liquid crystal array. The insertion loss was less than 3 dB;the attenuation tuning range was from 0 to 15 dB. The bandwidth tuning range was from 50 to 5000 GHz, which covered the full C band. The filter can meet the technical requirements of colorless-directionless-contentionlessflexible reconfigurable optical add/drop multiplexer. 相似文献
17.
N. Md. Yusoff M. H. Abu Bakar S. J. Sheih F. R. Mahamd Adikan M. A. Mahdi 《Laser Physics》2010,20(8):1747-1751
Erbium-doped fiber amplifier with flat gain over 30 nm bandwidth is demonstrated using flexible selective band methods. The
band optical amplifier was designed to cater 44 wavelength division multiplexing channels which were separated into bands
of 4 nm. Without using any gain flattening filter, the gain of optical amplifier was maintained at 19 dB with a maximum gain
variation of less than 1.6 dB even though the input signal power was varied from −19 to −6 dBm. The amplifier was able to
maintain 1 dB gain flatness with 83% chance for any selective bands of 4 nm within the wavelength range from 1530 to 1565
nm. This feature is very attractive to support band optical networks. 相似文献
18.
提出利用光纤中非线性效应受激喇曼散射(stimulated Raman scattering, SRS)实现波长转换的原理方案和相应的理论分析模型,并进行实验验证,将经过放大后的信号光和连续探测光同时注入光纤,在光纤中进行SRS放大,实现信号之间的转换。结果表明:利用SRS可实现波长转换,可实现跨几个THz的波长之间的转换。得到最大转换效率和消光比分别为-17.3 dB和15.7 dB。通过改变探测光的波长,可实现相隔几个THz光信号的全光波长转换和可调谐波长转换。 相似文献
19.
We investigated poly(styrene) (PSt)-based graded-index plastic optical fiber (GI-POF) with low loss and high bandwidth for home networks. To install the GI-POF in home networks, the attenuation must be below 200 dB/km at a 670-680 nm wavelength, and the bandwidth must be over 2.0 GHz for the 50 m fiber. In this study, we selected a dibenzothiophene (DBT) as a dopant to PSt, and we fabricated PSt-DBT-based GI-POF. We confirmed that the PSt-DBT-based GI-POF has high bandwidth (4.4 GHz) for 50 m fiber and low loss (166-193 dB/km) at a 670-680 nm wavelength and obtained the GI-POF that satisfied the requirements for home networks. 相似文献
20.
In this paper, a design of a generic multipurpose device is described. It can operate, in its basic structure, as a tunable
wavelength filter, wavelength multiplexer or λ router; by using a more complex structure, the device works as an optical add
drop multiplexer (OADM) or/and optical switch (OS). It can be used in both coarse and dense wavelength division multiplexing
technology (CWDM/DWDM) according to the network application. Performance parameters of the device, like switching time, losses,
crosstalk or polarization insensitivity are analyzed and compared with other switching technologies. Some applications of
the holographic WDM multifunction device in METRO networks are described, such as the utilization of OADMs in optical path
protection/reconfiguration between nodes (1 + 1 configuration) and the use of optical switches to interconnect nodes of the
METRO–access network with the METRO-Core or long haul networks in a reconfigurable topology. Other applications in Access
networks are possible, like the use of the OADMs in optical path protection between the optical line termination (OLT) at
the central office (CO) and the remote node (RN) in a fiber to the office passive-optical network (FTTO-PON) or, in some specific
cases, the utilization as tuneable holographic filters in a FTTO application, at the Business ONT (BONT), to select the assigned
optical wavelength according to the services provided to the customer. 相似文献