Investigation of modal power distribution in multimode fibers used in multiple in-line sensors

Author(s):  
Kim D. Bennett ◽  
A. U. Gencel
2015 ◽  
Author(s):  
Ruichen Tao ◽  
Takehiro Hayashi ◽  
Manabu Kagami ◽  
Shigeru Kobayashi ◽  
Manabu Yasukawa ◽  
...  

Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Alicia López ◽  
M. Losada ◽  
Javier Mateo ◽  
N. Antoniades ◽  
Xin Jiang ◽  
...  

Couplers and splitters are common devices in single-mode and multi-mode glass fibers applications, where they perform a variety of functions. However, when switching to plastic optical fibers (POFs), there is a shortage of commercial devices, which are usually custom-made. The problem with these devices is that modal power distribution in POFs is easily modified by spatial disturbances that produce a localized strong power transfer between modes, thus changing their transmission properties. In this work, a commercial Y-coupler designed for POFs is experimentally characterized. Measurements of its spectral, spatial and temporal characteristics have been performed, including insertion loss as a function of wavelength, angular power distribution, and frequency response. The obtained results show that this device has an equalizing effect over the power spatial distribution that reduces the fiber bandwidth, demonstrating the importance of considering the impact of this type of devices on the transmission properties of any POF system.


2020 ◽  
Vol 126 (10) ◽  
Author(s):  
Florian Schepers ◽  
Tim Hellwig ◽  
Carsten Fallnich

Abstract Transverse mode-locking in an end-pumped solid state laser by amplitude modulation with an acousto-optic modulator was investigated. Using the stochastic parallel gradient descent algorithm the modal power coefficients and the modal phases of the transverse mode-locked (TML) laser beam were reconstructed from the measured spatial and spatio-temporal intensity distributions, respectively. The distribution of the reconstructed modal power coefficients revealed that the average mode order of the transverse mode-locking process could be increased by a factor of about 8 compared to previous works, corresponding to an increase in the normalized oscillation amplitude by a factor of about 3. Furthermore, we found that besides a non-Poissonian modal power distribution, strong aberrations of the modal phases occurred in the experiment, resulting in a deformation of the oscillating spot. Additionally, we demonstrated the generation of up to four spots oscillating simultaneously on parallel traces by operating the TML laser on a higher mode order in the orthogonal direction to the transverse mode-locking process. TML lasers are of interest, e.g., for beam scanning purposes, as they have the potential to enable spot resolving rates in the multi-GHz regime.


1984 ◽  
Vol 5 (3) ◽  
Author(s):  
G. Cancellieri ◽  
U. Ravaioli

SummaryWhen two different multimode fibers are jointed together, mode mixing and mode filtering take place, with different characteristics in the two directions, leading to a non-symmetric behaviour. A detailed analysis of the power transitions among the guided modes at the joint is presented here. Explicit formulas for coupling efficiency and intermodal dispersion compensation are derived. The intentional mode mixing which is produced by suitable beam-launchers, in order to reach an optical power distribution independent of that of the optical source, is also investigated.


2008 ◽  
Vol 25 (12) ◽  
pp. 1998 ◽  
Author(s):  
O. I. Kotov ◽  
L. B. Liokumovich ◽  
A. H. Hartog ◽  
A. V. Medvedev ◽  
I. O. Kotov

Sign in / Sign up

Export Citation Format

Share Document