Experimental study on a broad and flat supercontinuum spectrum generated through a system of two PCFs

In this letter, the experimental results on a supercontinuum signal are presented based on a significantly broad and highly flat final spectrum (~810 nm and less than 3 dB). The supercontinuum was induced by two different microstructures in photonic crystal fibers (PCFs) with solid cores, pumped in the nanosecond regime (large pulses) by a Q-switched Nd:YAG laser. The simultaneous presence of both PCFs allowed an optimized spectrum to be obtained in comparison with the work reported in recent papers. The spectral evolution of a pump pulse propagating into the two PCFs was analyzed experimentally and the dispersion in the PCFs was estimated through numerical simulations. The broadening of the final spectrum was related to nonlinear phenomena such as modulation instability, stimulated Raman scattering, four-wave mixing, self-phase modulation, cross-phase modulation and the formation of higher-order solitons. The proposed scheme may have potential applications for the use of supercontinuum spectra in the areas of sensing, spectroscopy and metrology.

[1]  G Genty,et al.  Supercontinuum generation by nanosecond dual-wavelength pumping in microstructured optical fibers. , 2006, Optics express.

[2]  J. Hernández-García,et al.  Generation of long broadband pulses with a figure-eight fiber laser , 2011 .

[3]  Pedro Corredera,et al.  Supercontinuum generation using a continuous-wave Raman fiber laser , 2003 .

[4]  N.K. Nahar,et al.  Coupling Loss From Free Space to Large Mode Area Photonic Crystal Fibers , 2008, Journal of Lightwave Technology.

[5]  J R Taylor,et al.  Zero-dispersion wavelength decreasing photonic crystal fibers for ultraviolet-extended supercontinuum generation. , 2006, Optics express.

[6]  S. V. Chernikov,et al.  Dispersion measurement in optical fibres over the entire spectral range from 1.1 μm to 1.7 μm , 2000 .

[7]  J. M. Estudillo-Ayala,et al.  Supercontinuum generation in a standard fiber pumped by noise-like pulses from a figure-eight fiber laser , 2012 .

[8]  David J. Richardson,et al.  Holey optical fibers: an efficient modal model , 1999 .

[9]  Kunimasa Saitoh,et al.  Empirical relations for simple design of photonic crystal fibers. , 2005, Optics express.

[10]  R. Stolen,et al.  Optical wave breaking of pulses in nonlinear optical fibers. , 1985, Optics letters.

[11]  Everardo Vargas-Rodriguez,et al.  Estudio experimental sobre la evolución de los efectos no lineales que generan un espectro supercontinuo en fibras de cristal fotónico usando pulsos con duración de ns , 2011 .

[12]  A. Hasegawa,et al.  Generation of a train of soliton pulses by induced modulational instability in optical fibers. , 1984, Optics letters.

[13]  R. Grajales-Coutiño,et al.  Influencia de la inestabilidad modulacional en la generación de un espectro continuo en fibras ópticas con pulsos de nanosegundos , 2009 .

[14]  N. Akozbek,et al.  Tunable ultrashort laser pulses generated through filamentation in gases , 2006, 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference.

[15]  A. Kumar,et al.  Modal characteristics of few-mode silica-based photonic crystal fibres , 2000 .

[16]  Sheng-Ping Chen,et al.  7 W all-fiber supercontinuum source , 2011 .

[17]  Nathan R Newbury,et al.  Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared. , 2004, Optics letters.

[18]  Supercontinuum generation in a microstructured optical fiber by picosecond self Q-switched mode-locked Nd:GdVO4 laser , 2007 .

[19]  L. Mollenauer,et al.  Discovery of the soliton self-frequency shift. , 1986, Optics letters.

[20]  G. Ghosh,et al.  Temperature-dependent Sellmeier coefficients and chromatic dispersions for some optical fiber glasses , 1994 .

[21]  M. Rosenbluh,et al.  Spatial modes in a PCF fiber generated continuum , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[22]  Min Qiu,et al.  Analysis of guided modes in photonic crystal fibers using the finite‐difference time‐domain method , 2001 .

[23]  Y. Silberberg,et al.  Noiselike pulses with a broadband spectrum generated from an erbium-doped fiber laser. , 1997, Optics letters.

[24]  A. Luo,et al.  Sideband controllable soliton all-fiber ring laser passively mode-locked by nonlinear polarization rotation , 2009 .