The Study on the Effect Factors of Single-mode Fiber Optical Signal Transmission Time Delay

Research has been carried out to further investigate specifically the effect of sand powder, both the size of the sand grains and the thickness of the sand powder on the photodetector output as an advanced study of the single-mode optical fiber microbending loss theory in sand grains to pressure. This was done to investigate the response of optical fibers due to microbending loss to the load and determine the size of the sand particles that are most effectively used as a compiler of load sensors. The principle works to test the response of load sensors based on single-mode fiber optic microbending loss in the form of photodetector output when given a large variety of pressure. The method used in this research is to observe the reduction in the intensity of the light transmitted through optical fibers in the form of a voltage drop that is read by MMD that is connected to the photodetector. The reduced light intensity shows that the load sensor experiences optical attenuation of the laser as a light source with a wavelength of 1550 nm and a power of 1.47 mW. Microbending loss is caused by mechanical pressure that can change the direction of optical signal transmission and the radius of the curve is equal to or less than the diameter of a bare optical fiber. Observations were made using 12 load sensors with variations in the size of the sand grains in each diameter of the hose. The results of this study obtained the size of the most effective grains of sand providing microscopic curvature in the optical fiber that is 0.05 mm in terms of the correlation between the response of sensors with various diameters to changes in pressure.

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Switchable and tunable linear cavity erbium-doped fiber laser based on FBGs embedded in Sagnac rings

Laser Physics ◽

10.1088/1555-6611/ac3512 ◽

2021 ◽

Vol 32 (1) ◽

pp. 015101

Author(s):

Gangxiao Yan ◽

Weihua Zhang ◽

Peng Li ◽

Qiuhao Jiang ◽

Meng Wu ◽

...

Keyword(s):

Fiber Laser ◽

Low Cost ◽

Single Mode ◽

Optical Signal ◽

Single Mode Fiber ◽

Hole Burning ◽

Linear Cavity ◽

Erbium Doped ◽

Optical Fiber Sensing ◽

Birefringence Effect

Abstract A switchable and tunable erbium-doped fiber laser with a linear cavity based on fiber Bragg gratings embedded in Sagnac rings is proposed and experimentally verified. Due to the stress birefringence effect and the polarized hole burning effect, which are introduced into the single-mode fiber in the polarization controllers (PCs) by the PCs, the designed laser can achieve seven kinds of laser-states output including three kinds of single-wavelength laser states, three kinds of dual-wavelength laser states and one kind of triple-wavelength laser state. The optical signal-to-noise ratios of the output wavelengths are all higher than 52 dB, and the wavelength shifts are all less than 0.04 nm. Furthermore, the temperature tuning of the wavelength range is also researched, which is about 1.2 nm. Due to advantages, such as low cost, simple structure, easy switching and multiple laser states, the designed laser has great application potential in laser radar, optical fiber sensing and so on.

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Design and Characterization of low loss Single Mode Fiber for Terahertz Signal Transmission

2019 1st International Conference on Advances in Science, Engineering and Robotics Technology (ICASERT) ◽

10.1109/icasert.2019.8934665 ◽

2019 ◽

Author(s):

Akash Bosu ◽

Chaity Basak ◽

Shumaia Sharmin ◽

Khandaker Md. Tasrif Hossain ◽

Sharmina Zaman Urmi ◽

...

Keyword(s):

Signal Transmission ◽

Single Mode ◽

Single Mode Fiber ◽

Low Loss ◽

Terahertz Signal

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Microdrilled tapers to enhance optical fiber lasers for sensing

Scientific Reports ◽

10.1038/s41598-021-00046-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

R. A. Perez-Herrera ◽

M. Bravo ◽

P. Roldan-Varona ◽

D. Leandro ◽

L. Rodriguez-Cobo ◽

...

Keyword(s):

Optical Fiber ◽

Optical Fibers ◽

Fiber Lasers ◽

Signal To Noise Ratio ◽

Power Level ◽

Single Mode ◽

Optical Signal ◽

Single Mode Fiber ◽

Output Power Level ◽

Linear Cavity

AbstractIn this work, an experimental analysis of the performance of different types of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror is presented. These artificially-controlled backscattering fiber reflectors are used in short linear cavity fiber lasers. In particular, laser emission and sensor application features are analyzed when employing optical tapered fibers, micro-drilled optical fibers and 50 μm-waist or 100 μm-waist micro-drilled tapered fibers (MDTF). Single-wavelength laser with an output power level of about 8.2 dBm and an optical signal-to-noise ratio of 45 dB were measured when employing a 50 μm-waist micro-drilled tapered optical fiber. The achieved temperature sensitivities were similar to those of FBGs; however, the strain sensitivity improved more than one order of magnitude in comparison with FBG sensors, attaining slope sensitivities as good as 18.1 pm/με when using a 50 μm-waist MDTF as distributed reflector.

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Efficient Blind Adaptive CSE to Reduce Cyclic Prefix Length in Direct Detection Optical OFDM Systems

Journal of Optical Communications ◽

10.1515/joc-2018-0165 ◽

2019 ◽

Vol 0 (0) ◽

Author(s):

Asmaa Benieddi ◽

Sid Ahmed Elahmar

Keyword(s):

Orthogonal Frequency Division Multiplexing ◽

Direct Detection ◽

Group Velocity Dispersion ◽

Signal To Noise Ratio ◽

Single Mode ◽

Optical Signal ◽

Single Mode Fiber ◽

Cyclic Prefix ◽

Ofdm Systems ◽

Blind Adaptive

AbstractDirect detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems for a long-reach of standard single mode fiber (SSMF) require a large length of cyclic prefix (CP) to avoid the inter-symbol interference (ISI) effect caused by group velocity dispersion (GVD). Unfortunately, this method is inefficient due to the energy wasted in CP samples. In order to reduce the CP length and to mitigate the residual ISI, a novel blind adaptive channel shortening equalizer (CSE) is proposed in this paper. Based on the orthogonality between subcarriers in the fast Fourier transform (FFT) property, the proposed algorithm attempts to minimize the sum-squared correlation (SSCM) between each sample located in a well-defined window to update the CSE coefficients. Thus, the combined channel-CSE response is shortened. Therefore, it can cancel the residual ISI effect due to the GVD and the short CP length. The performance of the system is evaluated on basis of bit error rate (BER) versus optical signal to noise ratio (OSNR) for different CP lengths. The simulation results validate the new algorithm SSCM and show that it can reduce the CP length with a much better system improvement than existing algorithms.

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