Modified S2 imaging modal decomposition technique in Few Mode Fibers

  • Erick A. Lamilla Rubio ESPOL Polytechnic University, Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ciencias Naturales y Matemáticas (FCNM), Campus Gustavo Galindo Km. 30.5 Vía Perimetral P.O. Box 09-01-5863, Guayaquil - Ecuador


Precise knowledge of modal content in fibers that support diferent optical modes is important to understanding fiber properties and system performance. Several techniques have been implemented for modal content characterization in few mode fibers with the intention of identifying modes supported by these fibers. Direct modal characterization techniques have become popular for allowing a fairly accurate mode analysis as well as experimentally recover the mode amplitude and phase spatial profile. However, in some specific scenarios, certain limitations such as complete mode-recovery and resolution have to be overcome with these methods. In this paper are presented some modifications to a direct method of modal recovery that allow to remove several of those limitations. A mathematical implementation that consists of adding an external reference to the method is presented and studied, as well as the explanation of the proposed mode-recovery algorithm in detail.


Agrawal, G. P. (1989). Nonlinear fiber optics, chap. 5. AT&T–Academic press Inc.

Amezcua-Correa, R., G´erôme, F., Leon-Saval, S. G., Broderick, N. G. R., Birks, T. A., & Knight, J. C. (2008). Control of surface modes in low loss hollow-core photonic bandgap fibers. Opt. Express, 16(2):1142–1149. doi: 10.1364/OE.16.001142

Carpenter, J., Eggleton, B. J., & Schröder, J. (2016). Polarization-resolved cross-correlated (c2) imaging of a photonic bandgap fiber. Opt. Express, 24(24):27785–27790. doi: 10.1364/OE.24.027785

Jasapara, J. & Yablon, A. D. (2012). Spectrogram approach to S2 fiber mode analysis to distinguish between dispersion and distributed scattering. Opt. Lett., 37(18):3906–3908. doi: oi: 10.1364/OL.37.003906

Jung, Y., Sleiffer, V. A. J. M., Baddela, N., Petrovich, M. N., Hayes, J. R., Wheeler, N. V... Richardson, D. J. (2013). First demonstration of a broadband 37-cell hollow core photonic bandgap fiber and its application to high capacity mode division multiplexing. In 2013 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference (OFC/NFOEC), (p. 1-3).

Lamilla, E. (2019). Characterization and manipulation of optical modes in photonic crystal fibers: Caracteriza¸cao e manipulacao de modos opticos em fibras de cristal fotonico. Retrieved from

Lamilla, E., Aldaya, I., Serpa, C. M., Jarshel, P., & Dainese, P. C. (2016). Modal content in a 7-cell hollow-core photonic bandgap fiber and its depen- dence with offset launch conditions. In Latin America Optics and Photonics Conference, page LTu3C.3. Optical Society of America. doi: 10.1364/LAOP.2016.LTu3C.3

Lamilla, E., Faria, M. S., Aldaya, I., Jarschel, P. F., Pita, J. L., & Dainese, P. (2018). Characterization of surface-states in a hollow core photonic crystal fiber. Opt. Express, 26(25):32554–32564. doi: 10.1364/OE.26.032554

Newkirk, A. V., Antonio-Lopez, J. E., Anderson, J., Alvarez-Aguirre, R., Ez- naveh, Z. S., Lopez-Galmiche,... Schu¨lzgen, A. (2016). Modal analysis of antiresonant hollow core fibers using s2 imaging. Opt. Lett., 41(14):3277–3280. doi: 10.1364/OL.41.003277

Nguyen, D. M., Blin, S., Nguyen, T. N., Le, S. D., Provino, L., Thual, M., & Chartier, T. (2012). Modal decomposition technique for multimode fibers. Appl. Opt., 51(4):450–456. doi: 10.1364/AO.51.000450

Nicholson, J., Meng, L., Fini, J., Windeler, R., DeSantolo, A., Monberg, E.,... Ortiz, R. (2012). Measuring higher-order modes in a low-loss, hollow-core, photonic-bandgap fiber. Opt. Express, 20(18):20494–20505. doi: 10.1364/OE.20.020494

Nicholson, J. W., Yablon, A. D., Ramachandran, S., & Ghalmi, S. (2008). Spatially and spectrally resolved imaging of modal content in large-mode- area fibers. Opt. Express, 16(10):7233–7243. doi: 10.1364/OE.16.007233

Schimpf, D. N., Barankov, R. A., & Ramachandran, S. (2011). Cross- correlated (c2) imaging of fiber and waveguide modes. Opt. Express, 19(14):13008–13019. doi: 10.1364/OE.19.013008

Schmidt, O. A., Garbos, M. K., Euser, T. G., & Russell, P. S. J. (2012). Metrology of laser-guided particles in air-filled hollow-core photonic crystal fiber. Opt. Lett., 37(1):91–93. doi: 10.1364/OL.37.000091

Shapira, O., Abouraddy, A. F., Joannopoulos, J. D., & Fink, Y. (2005). Complete modal decomposition for optical waveguides. Phys. Rev. Lett., 94:143902. doi: 10.1103/PhysRevLett.94.143902

Song, K. Y. & Kim, Y. H. (2013). Characterization of stimulated brillouin scattering in a few-mode fiber. Opt. Lett., 38(22):4841–4844. doi: 10.1364/OL.38.004841

West, J. A., Smith, C. M., Borrelli, N. F., Allan, D. C., & Koch, K. W. (2004). Surface modes in air-core photonic band-gap fibers. Opt. Express, 12(8):1485–1496. doi: 10.1364/OPEX.12.001485