共查询到20条相似文献,搜索用时 968 毫秒
1.
光纤传感技术已广泛应用于航空航天、石油化工、电子电力、土木工程、生物医药等领域,其技术形式主要体现为分立式和分布式.分立式光纤传感技术利用光纤敏感器件作为传感器来感知被测参量的变化,光纤作为光信号的传输通道连接光纤传感器及后端的解调装置;分布式光纤传感系统基于光纤瑞利散射、拉曼散射或布里渊散射等光学效应,利用光纤本身作为传感器,可对沿途的光信号进行大范围、长距离传感.本文介绍了分立式与分布式光纤传感中主要关键技术的研究进展,并对未来的研究和发展方向进行了探讨. 相似文献
2.
从双包层光纤激光器的速率方程和光传输方程出发,建立数学模型,进行数值计算并对掺钕光纤激光器输出功率沿光纤的分布以及不同光纤长度下抽运功率和输出功率沿光纤的分布进行了数值模拟。以808nm半导体激光器为抽运源,掺钕双包层光纤为增益介质,并以KTP作为倍频晶体,计算并模拟其倍频效率和相位匹配角。最后,对光纤激光器及其倍频的实现进行了模拟研究。结果表明,该光纤激光器能够高效率地实现可见光输出。 相似文献
3.
Fiber optic sensors based on the interaction of surface plasmons or evanescent waves with the surrounding environment are usually obtained by tapering an optical fiber, which significantly weakens the structure, or by use of just the end of the optical fiber. A fiber optic structure that maintains the structural integrity of the optical fiber with a long environmental interaction length is presented. Graded-index optical fiber elements are used as lenses, and a coreless optical fiber acts as the environmental interaction area. These elements are fused by an optical fiber splicer and result in a continuous fiber optic sensing system. 相似文献
4.
锥形光纤间耦合特性的分析与检测 总被引:2,自引:0,他引:2
将通信光纤的末端拉制成锥形,利用光信号在光纤锥形区特有的传输和耦合特性,实现了光纤的耦合、连接和分束。用耦合模理论分析了锥形光纤间的传输和耦合性质,给出了光信号两锥形光纤间的耦合与两锥形光纤的距离和锥形区重叠长度等实验结果。 相似文献
5.
S. M. Idris F. Abdullah M. H. Al-Mansoori M. Z. Jamaludin N. M. Din 《Laser Physics》2010,20(4):855-858
In this paper, we report a fiber laser pressure sensor based on linear cavity erbium-doped fiber laser. The fiber laser structure
comprises of an erbium-doped fiber amplifier, a circulator, an optical coupler and a fiber Bragg grating (FBG) which acts
simultaneously as a lasing wavelength selecting components as well as a pressure sensor. The FBG is fitted to the shock tube
where the pressure is applied. The fiber laser pressure sensor has a low threshold power of 7 mW, an output power of 2.28
mW and an optical signal to noise ratio over 55 dB. The proposed fiber laser sensor is expected to be an attractive choice
for long-distance pressure monitoring. 相似文献
6.
研究在连续光入射下掺饵光纤光栅的开关动力学特征,发展其开关过程有类似于相变的特征。数值结果表明,主动光纤光栅在连续光条件下更适合于脉冲串产生。 相似文献
7.
氟锆酸盐玻璃光纤的研制 总被引:1,自引:0,他引:1
本文介绍聚全氟乙丙烯包皮的氟锆酸盐(ZrF_4-BaF_2-LaF_3-AlF_3-NaF)玻璃光纤的制备方法.研究了各种工艺因素对氟锆酸盐玻璃和光纤散射损耗的影响.结果表明,选择适当的熔化温度和均化时间,玻璃熔化和光纤拉制时环境中低的水含量是制得的损耗氟锆酸盐玻璃光纤的关键;配合料中引入适量NH_4HF_2,选用温度结构合理的拉丝炉及拉丝工艺也有助于降低光纤的损耗.在此工作基础上,获得了波长2.32μm处损耗为0.24dB/m的氟锆酸盐玻璃光纤. 相似文献
8.
9.
A microstructured polymer optical fiber doped with Rhodamine 6G dye was fabricated and demonstrated as an optical amplifier and a fiber laser. As an amplifier, the fiber achieved a gain in excess of 30 dB. As a pulsed fiber laser, the fiber exhibited a threshold of 20 microJ, a slope efficiency of 18%, and a lifetime as high as 130,000 shots at 10 Hz. The maximum output energy was 16 microJ. The advantages that such fibers offer lie in the simplicity and flexibility of their fabrication and in their potential for use as compact, tunable solid-state sources. 相似文献
10.
采用全矢量有限元方法进行光纤设计优化,得到横截面上失去两层空气洞的双芯光子晶体光纤,可用于液压传感.优化的双芯光子晶体光纤的模场半径和数值孔径与单模光纤基本一致,在优化的双芯光子晶体光纤和单模光纤之间有一个相对较低的熔接损耗.计算结果表明由模场半径和数值孔径导致的不匹配造成的总共损耗可低至0.026 dB,低于传统光子晶体光纤和单模光纤0.1 dB的直接熔接损耗.对基于20 cm双芯光子晶体光纤的液压传感器的性能进行研究,结果表明在0~500 MPa量程内的灵敏度为-1.6 pm/MPa. 相似文献
11.
12.
13.
Cavity-enhanced spectroscopy in optical fibers 总被引:3,自引:0,他引:3
Cavity-enhanced methods have been extended to fiber optics by use of fiber Bragg gratings (FBGs) as reflectors. High-finesse fiber cavities were fabricated from FBGs made in both germanium/boron-co-doped photosensitive fiber and hydrogen-loaded Corning SMF-28 fiber. Optical losses in these cavities were determined from the measured Fabry-Perot transmission spectra and cavity ring-down spectroscopy. For a 10-m-long single-mode fiber cavity, ring-down times in excess of 2 ms were observed at 1563.6 nm, and individual laser pulses were resolved. An evanescent-wave access block was produced within a fiber cavity, and an enhanced sensitivity to optical loss was observed as the external medium's refractive index was altered. 相似文献
14.
In this paper, a four-passed ytterbium-doped fiber amplifier (YDFA) is discussed. The gain and the pump and the signal light propagation characteristics of the four-passed YDFA are described. It is found that, while using a shorter length of the fiber, a four-passed fiber amplifier can realize the same output power as a single-pass fiber amplifier, and, for the same fiber lengths, a four-passed fiber amplifier offers a significantly higher power than its single-pass counterpart. 相似文献
15.
16.
17.
We report an all-fiber laser oscillator producing as much as 1.9 W of single-frequency direct output at 1.5 microm. Spatial gain hole burning in the active fiber has been eliminated by use of a twisted-mode cavity approach. The two short pieces of a polarization-maintaining fiber that were spliced to the ends of the active fiber served as ultracompact quarter-wave plates. To our knowledge, the use of such a wave plate to manipulate the polarization state of light inside a fiber laser cavity is reported here for the first time. The laser output is linearly polarized and delivered through a polarization-maintaining fiber pigtail. We believe that the output power of our laser is the highest among all single-frequency fiber laser oscillators reported to date. 相似文献
18.
We present a theoretical and experimental investigation of a Sagnac interferometer incorporating a fiber optic recirculating-ring delay line with an erbium-doped fiber amplifier to increase the effective length of the Sagnac loop and thereby improve the low-frequency response. Theoretical calculations show that the low-frequency response of the interferometer is enhanced as expected. However, the noise penalty of using a fiber amplifier in the ring is quite high, especially at low frequencies. The signal-to-noise ratio at low frequencies, using a superfluorescent erbium fiber source, is demonstrated as increasing by a factor of 2 compared to a single-loop Sagnac interferometer with the same total length of fiber, but without fiber amplifier. 相似文献
19.
We have constructed a low-cost, double-cavity erbium-doped fiber ring laser with a fiber Bragg grating and a 2×2 coupler. A high output power of 8.7 dBm and a signal-to-noise-floor ratio of 43 dB were demonstrated. This fiber grating ring laser is used as the light source for the 2.488 Gb/s transmission experiment through a 100 km single mode fiber. To our knowledge, this is the first time a fiber grating ring laser is being used as an externally modulated source for digital transmission. 相似文献
20.
Zhu X Schülzgen A Li H Li L Wang Q Suzuki S Temyanko VL Moloney JV Peyghambarian N 《Optics letters》2008,33(9):908-910
An alternative original approach to achieve single-transverse-mode laser emissions from multimode (MM) active fibers is demonstrated. The fiber cavity is constructed by simply splicing a conventional passive single-mode fiber (SMF-28) onto a few centimeters-long active MM fiber section whose length is precisely controlled. Owing to the self-imaging property of multimode interference (MMI) in the MM fiber, diffraction-limited laser output is obtained from the end of the SMF-28, and the MMI fiber laser is nearly as efficient as the corresponding MM fiber laser. Moreover, because of the spectral filtering effect during in-phase MMI, the bandwidth of the MMI fiber laser is below 0.5 nm. 相似文献