OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 16, Iss. 10 — May. 12, 2008
  • pp: 7233–7243

Spatially and spectrally resolved imaging of modal content in large-mode-area fibers

J. W. Nicholson, A. D. Yablon, S. Ramachandran, and S. Ghalmi  »View Author Affiliations

Optics Express, Vol. 16, Issue 10, pp. 7233-7243 (2008)

View Full Text Article

Enhanced HTML    Acrobat PDF (396 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



A new measurement technique, capable of quantifying the number and type of modes propagating in large-mode-area fibers is both proposed and demonstrated. The measurement is based on both spatially and spectrally resolving the image of the output of the fiber under test. The measurement provides high quality images of the modes that can be used to identify the mode order, while at the same time returning the power levels of the higher-order modes relative to the fundamental mode. Alternatively the data can be used to provide statistics on the level of beam pointing instability and mode shape changes due to random uncontrolled fluctuations of the phases between the coherent modes propagating in the fiber. An added advantage of the measurement is that is requires no prior detailed knowledge of the fiber properties in order to identify the modes and quantify their relative power levels. Because of the coherent nature of the measurement, it is far more sensitive to changes in beam properties due to the mode content in the beam than is the more traditional M2 measurement for characterizing beam quality. We refer to the measurement as S patially and S pectrally resolved imaging of mode content in fibers, or more simply as S2 imaging.

© 2008 Optical Society of America

OCIS Codes
(060.2270) Fiber optics and optical communications : Fiber characterization
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators

ToC Category:
Fiber Optics and Optical Communications

Original Manuscript: February 19, 2008
Revised Manuscript: April 2, 2008
Manuscript Accepted: April 6, 2008
Published: May 5, 2008

J. W. Nicholson, A. D. Yablon, S. Ramachandran, and S. Ghalmi, "Spatially and spectrally resolved imaging of modal content in large-mode-area fibers," Opt. Express 16, 7233-7243 (2008)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. A. E. Siegman, "Defining, Measuring, and Optimizing Laser Beam Quality," in Proc. SPIE, 2 (1993).
  2. H. Yoda, O. Polynkin, and M. Mansuripur, "Beam Quality Factor of Higher Order Modes in a Step-Index Fiber," J. Lightwave Technol. 24, 1350-1355 (2006). [CrossRef]
  3. S. Wielandy, "Implications of Higher-Order Mode Content in LargeMode Area Fibers with Good Beam Quality," Opt. Express 15, 402-409 (2007). [CrossRef]
  4. C. R. S. Fludger and R. J. Mears, "Electrical Measurements of Multipath Interference in Distributed Raman Amplifiers," J. Lightwave Technol. 19, 536-545 (2001). [CrossRef]
  5. S. Ramachandran, J. W. Nicholson, S. Ghalmi, and M. F. Yan, "Measurement of Multipath Interference in the Coherent Crosstalk Regime," IEEE Photon. Technol. Lett. 15, 1171-1173 (2003). [CrossRef]
  6. S. Ramachandran, S. Ghalmi, J. Bromage, S. Chandrasekhar, and L. L. Buhl, "Evolution and Systems Impact of Coherent Distributed Multipath Interference," IEEE Photon. Technol. Lett. 17, 238-240 (2005). [CrossRef]
  7. M. E. Fermann, "Single-Mode Excitation of Multimode Fibers with Ultrashort Pulses," Opt. Lett. 23, 52-54 (1998). [CrossRef]
  8. F. Gori, M. Santarsiero, R. Borghi, and G. Guattari, "Intensity-Based Modal Analysis of Partially Coherent Beams with Hermite-Gaussian Modes," Opt. Lett. 23, 989-991 (1998). [CrossRef]
  9. C. Rydberg and J. Bengtsson, "Numerical Algorithm for the Retrieval of Spatial Coherence Properties of Partially Coherent Beams from Transverse Intensity Measurements," Opt. Express 15, 613-623 (2007). [CrossRef]
  10. M. Skorobogatiy, C. Anastassiou, S. G. Johnson, O. Weisberg, T. D. Engeness, S. A. Jacobs, R. U. Ahmad, and Y. Fink, "Quantitative Characterization of Higher-Order Mode Converters in Weakly Multi-Moded Fibers," Opt. Express 11, 2838-2847 (2003). [CrossRef] [PubMed]
  11. D. B. S. Soh, J. Nilsson, S. Baek, C. Codemard, Y. C. Jeong, and V. Philippov, "Modal Power Decomposition of Beam Intensity Profiles Into Linearly Polarized Modes of Multimode Optical Fibers." J. Opt. Soc. Am. A 21, 1241-1250 (2004). [CrossRef]
  12. O. Shapira, A. F. Abouraddy, J. D. Joannopoulos, and Y. Fink, "Complete Modal Decomposition for Optical Waveguides," Phys. Rev. Lett. 94, 143-902 (2005). [CrossRef]
  13. J. R. Fienup, "Phase Retrieval Algorithms : A Comparison," Appl. Opt. 21, 2758 (1982). [CrossRef] [PubMed]
  14. J. M. Fini, "Bend-Resistant Design of Conventional and Microstructure Fibers with Very Large Mode Area," Opt. Express 14, 69-81 (2006). [CrossRef] [PubMed]
  15. J. W. Nicholson, J. M. Fini, A. D. Yablon, P. S. Westbrook, K. Feder, and C. Headley, "Demonstration of Bend-Induced Nonlinearities in Large-Mode-Area Fibers," Opt. Lett. 32, 2562-2564 (2007). [CrossRef] [PubMed]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Supplementary Material

» Media 1: AVI (3058 KB)     
» Media 2: AVI (3066 KB)     
» Media 3: AVI (3093 KB)     

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited