- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Broadband generation of the first-order OAM modes in two-mode fiber by offset splicing and fiber rotating technology
摘要： We demonstrate a simple, compact, and cost-effective all-fiber structure to generate the first-order orbital angular momentum (OAM) modes over a broad wavelength range. The offset splicing between a polarization-maintaining single mode fiber (PM-SMF) and a two-mode fiber (TMF) is adopted to excite LP11 mode in the TMF from LP01 mode in SMF. Then the OAM ± 1,1 modes are generated by rotating a customized fiber rotator, which can modulate the phase difference of the two degenerate LP11 modes (OAM ± 1,1 = LP11a ± i × LP11b). The interference phenomenon formed between OAM and Gaussian beams, which displays a fork-shape or spiral interference pattern, is used to confirm the generation of OAM modes. It should be noted that a PM fiber coupler and PM-SMFs are utilized in the experiment, which can avoid coupling of modes with orthogonal polarizations and then improves the OAM mode stability. Besides, the complexity of the OAM generation system is also reduced because the devices like polarization controller and half-wave plate are omitted by employing PM fibers. Based on this simple offset splicing and fiber rotating technology, the broadband generation of OAM ± 1,1 modes are experimentally demonstrated in wavelength range of 1530–1566 nm.
关键词： Fiber rotating,Polarization-maintaining single mode fiber,Two mode fiber,Offset-splicing,Orbital angular momentum mode
更新于2025-09-23 15:23:52
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Comparative analysis of capacity oriented Integrated AMI modulation technique for the deployment of radio over fiber system
摘要： To improve the spectral efficiency and to reduce non-linear distortion in the optical system, various advanced modulation techniques have been investigated for radio over fiber (RoF) system. The investigation indicates the high data rate distortion less transmission for long-haul RoF system still further investigation is required to improve spectral efficiency and to get the reduction in signal degradation. In this paper, an advanced modulation technique referred as integrated alternate mark inversion modulation technique based upon external modulation (electro-absorption modulator) has been designed and simulated. The results show better performance in terms of performance metrics i.e. Q-factor (25.15) and BER (4e-140) and also enhance the data transmission capabilities up to 100 Gbps covering the long distance of 250 km resulting a reasonable reduction in signal degradation particularly chromatic dispersion effects for long-haul transmissions.
关键词： Single mode fiber—SMF,Carrier suppressed return to zero—CSRZ,Erbium doped fiber amplifier—EDFA,RoF,Dispersion compensating fiber—DCF,Multi-mode fiber—MMF
更新于2025-09-23 15:23:52
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Estimation of Signal-to-Cross Talk Ratio of Stimulated-Raman-Scattering-Induced Cross Talk in Wavelength-Division-Multiplexing-Based Radio-over-Fiber Links
摘要： This paper evaluates the signal-to-cross talk ratio (SXR) of cross talk induced by stimulated Raman scattering (SRS) in radio-over-fiber (RoF) systems based on wavelength-division multiplexing. The reported study has modeled the relations of SXR to modulation frequency, optical power, transmission length, and effective area of fiber for various values of the walk-off parameter. The summary of experimental reveals that SXR decreases with increases in channel input power and transmission distance and increased with increases in fiber effective area and modulation frequency. Results showed that increasing the walk-off parameter from 13.6 to 81.6 ps/km increased the SXR by almost 6 dBm. Furthermore, various fibers, including standard single-mode fiber (SMF), Corning LEAF, and Alcatel TeraLight were tested for their capacity to mitigate SRS-induced cross talk. These tests demonstrated that standard SMF suppressed SRS cross talk effectively and offered values of SXR 3 dBm and 6 dBm higher than the values exhibited by Alcatel TeraLight and Corning LEAF, respectively.
关键词： wavelength-division multiplexing (WDM),signal-to-cross talk ratio (SXR),stimulated Raman scattering (SRS),single-mode fiber (SMF),radio over fiber (RoF)
更新于2025-09-23 15:22:29
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[IEEE 2019 Workshop on Recent Advances in Photonics (WRAP) - Guwahati, India (2019.12.13-2019.12.14)] 2019 Workshop on Recent Advances in Photonics (WRAP) - Micro-channeled Single Mode Fiber Plasmonic Sensor with ITO-TiO <sub/>2</sub> Bilayer
摘要： A microchannel incorporated single mode fiber plasmonic sensor coated with ITO-TiO2 bilayer is proposed in this paper. The sensor responds over a wide refractive index range from 1.33 to 1.41 and sensitivity of 10500nm/RIU is obtained for refractive index 1.41. oxide which is employed to enhance the evanescent field. By taking the aid of a conventional SMF which offers significant cost reduction and good compatibility, our proposed structure achieves reasonably high sensitivity along with wide sensing range.
关键词： sensitivity,Single mode fiber,refractive index
更新于2025-09-23 15:21:01
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A novel star shape photonic crystal fiber for low loss terahertz pulse propagation
摘要： An extremely low loss circle-based star shape photonic crystal fiber (CS-PCF) has been proposed for terahertz (THz) spectrum. A dielectric material TOPAS has been used for constructing the proposed model. Some important parameters for the proposed waveguide have been investigated a wide THz spectrum ranging from 0.5 to 2.50 THz. The simulation result exhibits an extremely-low material loss of 0.01607 cm-1 and a large effective area of 1.386 × 106 μm2 at 1.0 THz frequency with 55% core porosity. In addition, the proposed structure establishes comparatively higher core power fraction maintaining lower scattering loss about 1.235 × 10-15 dB/cm and 91.97% of bulk absorption material loss at the same operating frequency. From the above results, it is anticipated that proposed CS-PCF model of the THz waveguide will make the conventional communication very effective over the current designs.
关键词： Effective material Loss,Scattering Loss,Power Fraction,THz Application,Single Mode Fiber
更新于2025-09-23 15:21:01
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Femtosecond laser direct written off-axis fiber Bragg gratings for sensing applications
摘要： First order off-axis fiber Bragg gratings (FBGs) were fabricated in a standard single mode fiber (SMF-28e) through femtosecond laser direct writing. A minimum offset distance between the grating and core center of 2.5 μm was found to create a multimode section, which supports two separate fiber modes (LP0,1 and LP1,1), each split into two degenerate polarization modes. The resulting structure breaks the cylindrical symmetry of the fiber, introducing birefringence (≈10?4) resulting in a polarization dependent Bragg wavelength for each mode. Based on the modal and birefringence behavior, three off-axis FBGs were fabricated with 3.0, 4.5 and 6.0 μm offsets from the core center, and then characterized in strain, temperature, and curvature. The tested off-axis FBGs exhibited a similar strain sensitivity of ~1.14 pm/μ? and a temperature sensitivity of ~12 pm/C. The curvature and orientation angle were simultaneously monitored by analyzing the intensity fluctuation and the wavelength shift of the LP1,1 Bragg resonance. A maximum curvature sensitivity of 0.53 dB/m?1 was obtained for the off-axis FBG with a 3.0 μm offset.
关键词： optical fiber sensors,femtosecond laser direct writing,single mode fiber,off-axis fiber Bragg gratings,Birefringence
更新于2025-09-23 15:19:57
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Optical fiber temperature sensor based on a Mach-Zehnder interferometer with single-mode-thin-core-single-mode fiber structure
摘要： A Mach-Zehnder interferometer for measurement of temperature is proposed and experimentally demonstrated, which consists of two sections of single mode fiber (SMF) and a section of thin core fiber spliced between the two SMFs. The two welding areas are heated and stretched to improve the split and recombination of light. The wavelength of the resonant dip will shift when temperature varies due to the thermo-optic and thermal expansion effect. The experimental results show that a temperature sensitivity of 65 pm/○C with a linear correlation coefficient of 0.996 can be achieved in a temperature range from 25 ○C to 80 ○C. Due to its ease of manufacture, low cost, and high sensitivity, the fiber optic temperature sensor is suitable for temperature measurement applications.
关键词： single-mode-thin-core-single-mode fiber structure,Mach-Zehnder interferometer,Optical fiber temperature sensor
更新于2025-09-19 17:13:59
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Review of the technology of a single mode fiber coupling to a laser diode
摘要： In this paper, the technology of a single mode fiber coupling to a semiconductor laser diode has been summarized and the latest developments in the bulk optics coupling scheme and the microlens fiber coupling scheme have been reviewed. The review has focused on optimizing the optical structure and the coupling parameters to improve the coupling efficiency and packaging performance. The advanced manufacturing technology as well as common modeling methods and applications of coupling systems have also been reviewed. Finally, the paper has summarized the key technologies of a single mode fiber coupling to a laser diode and its direction of development in the future.
关键词： Single mode fiber,Coupling efficiency,Bulk optics,Optical structure,Microlens fiber,Manufacturing technology,Laser diode
更新于2025-09-19 17:13:59
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Analysis of Four Wave Mixing Effects in 16 ??10 Gb/S WDM Optical Communication System
摘要： The fiber nonlinearities are one of the main performance limiting factors in any optical communication system. There are several parameters that effectively contribute in mitigation of these fiber nonlinearities such as fiber dispersion, effective area of fiber core, etc. Here, we have investigated the four wave mixing (FWM) nonlinear impairments in 16-channel WDM system. The FWM crosstalk becomes very critical to handle for long haul transmission systems at high power levels. Here, 16 channels WDM is being implemented and its performance is evaluated in terms of bit error rate (BER), Q factor, etc. for distance transmission upto 500 km.
关键词： passive optical networks (PONs),single mode fiber (SMF),four wave mixing (FWM)
更新于2025-09-19 17:13:59
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Optical fiber relative humidity sensor based on FBG embedded in SMS fiber structure
摘要： A novel optical fiber humidity sensor based on fiber Bragg grating (FBG) embedded in single-mode-multimode-single-mode (SMS) fiber structure is proposed. With relative humidity (RH) changing, the transmission spectrum of the SMS fiber structure shifts while the central wavelength of FBG remains unchanged. Numerical simulations of light distribution of the SMS structure have been carried out, analyzing the effects of different wavelengths of the input light, lengths and core diameters of the multimode fiber (MMF). The cross-sensitive problem of temperature has also been solved.
关键词： relative humidity measurement,FBG,Single-mode-multimode-single-mode fiber structure
更新于2025-09-16 10:30:52