Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Variable optical attenuator and dynamic mode group equalizer for few mode fibers

Miri Blau, Israel Weiss, Jonathan Gerufi, David Sinefeld, Moran Bin-Nun, Robert Lingle, Lars Grüner-Nielsen, and Dan M. Marom

Open Access Open Access

Abstract

Variable optical attenuation (VOA) for three-mode fiber is experimentally presented, utilizing an amplitude spatial light modulator (SLM), achieving up to −28dB uniform attenuation for all modes. Using the ability to spatially vary the attenuation distribution with the SLM, we also achieve up to 10dB differential attenuation between the fiber’s two supported mode group (LP01 and LP11). The spatially selective attenuation serves as the basis of a dynamic mode-group equalizer (DME), potentially gain-balancing mode dependent optical amplification. We extend the experimental three mode DME functionality with a performance analysis of a fiber supporting 6 spatial modes in four mode groups. The spatial modes’ distribution and overlap limit the available dynamic range and performance of the DME in the higher mode count case.

© 2014 Optical Society of America

Full Article  |  PDF Article
More Like This
Modeling and characterization of a few-mode EDFA supporting four mode groups for mode division multiplexing

Guillaume Le Cocq, Laurent Bigot, Antoine Le Rouge, Marianne Bigot-Astruc, Pierre Sillard, Clemens Koebele, Massimilliano Salsi, and Yves Quiquempois
Opt. Express 20(24) 27051-27061 (2012)

Wavelength-selective switch with direct few mode fiber integration

D. M. Marom, J. Dunayevsky, D. Sinefeld, M. Blau, R. Ryf, N. K. Fontaine, M. Montoliu, S. Randel, C. Liu, B. Ercan, M. Esmaeelpour, S. Chandrasekhar, A. H. Gnauck, S. G. Leon-Saval, J. Bland-Hawthorn, J. R. Salazar-Gil, Y. Sun, L. Grüner-Nielsen, and R. Lingle
Opt. Express 23(5) 5723-5737 (2015)

Single-mode fiber variable optical attenuator based on a ferrofluid shutter

Anna Duduś, Robert Blue, and Deepak Uttamchandani
Appl. Opt. 54(8) 1952-1957 (2015)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (7)
Fig. 1
Fig. 1 Application of SMF-VOA solutions to FMF resulting in uneven mode attenuation and mode mixing. (A) Three spatial fiber modes. (B) VOA by MEMS beam steering. The imaged beam is detuned from the fiber facet, resulting in overlap integral between offset modes. (C) VOA by MEMS shutter. The beam is clipped, resulting in overlap integral over the remaining beam regions.

Download Full Size | PDF

Fig. 2
Fig. 2 (a) Polarization-diverse free-space optical arrangement of dynamic mode-group optical attenuator with amplitude spatial light modulator. (b) Experimental characterization technique using swept laser interferometry, obtaining full device complex matrix response.

Download Full Size | PDF

Fig. 3
Fig. 3 FMF-VOA functionality. A) Flat response of attenuation over 25dB of attenuation. B) MDL at different attenuation values. MDL shows no increase until attenuation level reaches noise floor. Observed constant MDL is that of mux/ demux system; VOA settings do not alter it.

Download Full Size | PDF

Fig. 4
Fig. 4 NIR images of reflected optical beam from LCoS SLM. a) LP01 mode excitation, b) LP11 mode group excitation, c) both mode groups illuminate SLM with circular block attenuation pattern applied for predominantly LP01 suppression and d) both spatial mode groups with circular aperture attenuating pattern for LP11 suppression.

Download Full Size | PDF

Fig. 5
Fig. 5 Dynamic mode group equalizer responses. (a-b) Simulation and (c-d) measurement results of attenuation, employing a blocking circle (a, c) or blocking aperture (b, d) pattern. As the blocking radius increases, both modes attenuate, with the LP01 incurring significant loss earlier. For the circular apertures, both modes’ transmission increase with aperture radius, with the LP01 transmission rising earlier.

Download Full Size | PDF

Fig. 6
Fig. 6 Intensity patterns of the first four mode groups in a six mode fiber: (a) LP01 mode (b) LP11 mode group (c) LP21 mode group and (d) LP02 mode. (e) Radial mode intensity distribution of the four mode groups. Dashed vertical lines denotes the core-cladding interface. (f) Radial Fourier transform intensity distribution of the four mode groups.

Download Full Size | PDF

Fig. 7
Fig. 7 Dynamic mode group equalizer response simulations for a six mode fiber. Blocking and transmitting annular patterns for specific mode attenuation:(a) attenuating LP01 mode (b) attenuating LP21 mode (c) attenuating LP11 mode (d) attenuating LP21 mode (e) attenuating LP02 mode

Download Full Size | PDF

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

[ φ ⌢ 1 φ ⌢ 2 φ ⌢ 3 φ ⌢ 4 ]= [ ξ 11 0 0 ξ 14 0 ξ 22 0 0 0 0 ξ 33 0 ξ 41 0 0 ξ 44 ] ︸ DME [ 2 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 ] ︸ DMG [ φ 1 φ 2 φ 3 φ 4 ]
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use