High performance single mode OTDR using coherent detection and fibre amplifiers

1990 ◽  
Vol 26 (9) ◽  
pp. 573 ◽  
Author(s):  
Y. Koyamada ◽  
H. Nakamoto
Keyword(s):  
High Performance ◽  
Single Mode ◽  
Coherent Detection ◽  
Fibre Amplifiers

Solution-processed whispering-gallery-mode microsphere lasers based on colloidal CsPbBr3 perovskite nanocrystals

2021 ◽  
Author(s):  
Minghong Xie ◽  
Wenxiao Gong ◽  
Lei Kong ◽  
Yang Liu ◽  
Yang Mi ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Single Mode ◽  
Whispering Gallery Mode ◽  
Solution Processed ◽  
Time Resolved ◽  
Perovskite Nanocrystals ◽  
Whispering Gallery ◽  
Low Threshold ◽  
The Stability

Abstract Perovskite nanocrystals (NCs) have emerged as attractive gain materials for solution-processed microlasers. Despite the recent surge of reports in this feld, it is still challenging to develop low-cost perovskite NCbased microlasers with high performance. Herein, we demonstrate low-threshold, spectrally tunable lasing from ensembles of CsPbBr3 NCs deposited on silica microspheres. Multiple whispering-gallery-mode lasing is achieved from individual NC/microspheres with a low threshold of ∼3.1 µJ cm−2 and cavity quality factor of ∼1193. Through time-resolved photoluminescence measurements, electron-hole plasma recombination is elucidated as the lasing mechanism. By tuning the microsphere diameter, the desirable single-mode lasing is successfully achieved. Remarkably, the CsPbBr3 NCs display durable room-temperature lasing under ∼107 shots of pulsed laser excitation, substantially exceeding the stability of conventional colloidal NCs. These CsPbBr3 NC-based microlasers can be potentially useful in photonic applications.

scholarly journals Distributed Fiber Birefringence Measurement Using Pulse-Compression Φ-OTDR

2020 ◽  
Author(s):  
Yongxiang Chen ◽  
Yun Fu ◽  
Ji Xiong ◽  
Zinan Wang
Keyword(s):  
Spatial Resolution ◽  
Pulse Compression ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Time Domain Reflectometry ◽  
Coherent Detection ◽  
Compression Phase ◽  
Optical Time Domain Reflectometry ◽  
Fiber Birefringence ◽  
Optical Time

Abstract In this paper, a novel birefringence measurement method through the Rayleigh backscattered lightwave within single-mode fiber is proposed, using a single chirped-pulse with arbitrary state of polarization. Numerical analysis is carried out in detail, then pulse-compression phase-sensitive optical time domain reflectometry (PC-Φ-OTDR) with polarization-diverse coherent detection is employed to verify this method. A 2km spun single-mode fiber is tested with 8.6 cm spatial resolution, and the average birefringence of the fiber under test is measured as 0.234rad/m, which is consistent with previous literatures about single-mode fiber. Moreover, the relationship between the measured birefringence and the spatial resolution is also studied for the first time, and the results show that spatial resolution is crucial for fiber birefringence measurement.

Application of Fiber Point Diffraction in Measurement of Optical Surface

2011 ◽  
Vol 55-57 ◽  
pp. 1200-1205
Author(s):  
Liang Nie ◽  
Jun Han ◽  
Xu Jiang
Keyword(s):  
High Performance ◽  
Spherical Surface ◽  
Spherical Wave ◽  
Numerical Aperture ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Optical Surface ◽  
Fiber System ◽  
Core Diameter ◽  
Fringe Contrast

The fiber point diffraction technology is applied in interferometer to measure optical surface with high precision. The wavefront diffracted from the single mode fiber with microns core diameter can be considered as ideal spherical wave and used as the referenced wave in interferometry. To estimate the quality of diffracted wavefront, the theoretical model of optical point diffraction is introduced at first. Based on the model, the influence of fiber core diameter, deformation and end-face shape on wavefront error is studied with numerical analysis. The analysis result shows that the single mode fiber used in experiment is available for instrument design and its influence over systematic error should be negligible within certain numerical aperture. Then a point diffraction interferometer with a single fiber is designed. Compared with the double fiber system, it has merit of noise immunity, high fringe contrast and high performance. Finally, the fiber point diffraction interferometer system is put up to measure spherical surface in experiment. The interference fringes are collected and analyzed with five-step shifting, least squares unwrapping and Zernike fitting method. The results show that the interferometer with optical fiber has achieved a worthy measurement precision and has great development potential.

Chaos Control in Single Mode Approximation of T-AFM Systems Using Nonlinear Delayed Feedback Based on Sliding Mode Control

2007 ◽  
Author(s):  
Hoda Sadeghian ◽  
Mehdi Tabe Arjmand ◽  
Hassan Salarieh ◽  
Aria Alasty
Keyword(s):  
Feedback Control ◽  
High Performance ◽  
Sliding Mode ◽  
Chaotic Behavior ◽  
Single Mode ◽  
Delayed Feedback ◽  
Delayed Feedback Control ◽  
Model Parameters ◽  
Unstable Periodic Orbits ◽  
Single Mode Approximation

The taping mode Atomic Force Microscopic (T-AFM) can be properly described by a sinusoidal excitation of its base and nonlinear potential interaction with sample. Thus the cantilever may cause chaotic behavior which decreases the performance of the sample topography. In this paper a nonlinear delayed feedback control is proposed to control chaos in a single mode approximation of a T-AFM system. Assuming model parameters uncertainties, the first order Unstable Periodic Orbits (UPOs) of the system is stabilized using the sliding nonlinear delayed feedback control. The effectiveness of the presented methods is numerically verified and the results show the high performance of the controller.

scholarly journals New optical fibres for high-capacity optical communications

2016 ◽  
Vol 374 (2062) ◽  
pp. 20140441 ◽  
Author(s):  
D. J. Richardson
Keyword(s):  
High Capacity ◽  
Single Mode ◽  
Cost Effective ◽  
Network Capacity ◽  
Optical Fibres ◽  
Single Mode Fibre ◽  
Fibre Transmission ◽  
Fibre Amplifiers ◽  
Fibre Loss ◽  
Mode Fibre

Researchers are within a factor of 2 or so from realizing the maximum practical transmission capacity of conventional single-mode fibre transmission technology. It is therefore timely to consider new technological approaches offering the potential for more cost-effective scaling of network capacity than simply installing more and more conventional single-mode systems in parallel. In this paper, I review physical layer options that can be considered to address this requirement including the potential for reduction in both fibre loss and nonlinearity for single-mode fibres, the development of ultra-broadband fibre amplifiers and finally the use of space division multiplexing.

Near-Zero Shift Attachment for Optoelectronic Components

2011 ◽  
Vol 2011 (1) ◽  
pp. 001058-001066
Author(s):  
Roy J. Bourcier
Keyword(s):  
Optical Fibers ◽  
High Performance ◽  
Coupling Efficiency ◽  
Single Mode ◽  
Optical Coupling ◽  
Free Space Optical ◽  
Optical Elements ◽  
Uv Curable ◽  
Design Concepts ◽  
Process Elements

High performance laser-based optoelectronic devices commonly feature the use of free-space optical coupling between the laser diode and optical elements such as filters, secondary harmonic generators and optical fibers. A critical challenge in the assembly of such components is maintaining the required optical alignment precision during attachment of the optical subcomponents to a common platform. In the case of devices based on single mode waveguides, the post-attach shift must often be held to less than a few hundred nanometers to achieve the desired optical coupling efficiency. Historically, these tight tolerances have required the use of costly post-work operations such as laser hammering or re-bend to achieve performance objectives. Over the course of designing several such optoelectronic components, we have used and developed a variety of design concepts and assembly processes which have allowed us to achieve these demanding tolerances, often without the use of post-work. UV-curable structural adhesives and Nd:YAG laser spot welding have been used, individually and in combination, to perform the required sub-micron optomechanical attachments. Several approaches which have been successfully used will be described and their relative merits will be compared. In addition, key design and process elements which can impact post-attach shift will be discussed.

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