All-solid Microstructured Optical Fiber Research Articles

Coherent mid-infrared supercontinuum generation in tellurite all-solid microstructured optical fibers with anomalous and normal dispersion property

Tellurite all-solid hybrid microstructured optical fibers (ASHMOFs) can be used to generate supercontinua with broad bandwidths in both anomalous and normal dispersion regimes. In the anomalous dispersion regime, a supercontinuum spectrum from 1.1 to 6.7 μm can be generated with a pump power of 10 kW and a pump wavelength of 3.5 μm. In the normal dispersion regime, a supercontinuum spectrum from 2.0 to 4.4 μm can be generated with the same pump power and wavelength. The simulations of supercontinuum generation in ASHMOFs show promising results for applications such as broadband infrared spectroscopy and enviromental monitoring. The all-solid nature of these fibers also makes them more robust and easier to handle than conventional soft-glass fibers.

Ultrabroadband and coherent mid-infrared supercontinuum generation in all-normal dispersion Te-based chalcogenide all-solid microstructured fiber

We report an ultrabroadband supercontinuum (SC) generation with high coherence property in all-normal-dispersion (ANDi) Te-based chalcogenide all-solid microstructured optical fiber (AS-MOF). The fiber was fabricated using a rod-in-tube method that presents four A s 2 S 3 glass rods selected as low refractive index material ( n = 2.4 ) embedded in a G e 20 A s 20 S e 20 T e 40 glass matrix ( n = 3.1 ). The highly symmetrical four-hole MOF preform was fabricated through the computerized numerical control precision mechanical drilling method. By engineering the structure of the fiber, we determined an ANDi characteristic in the range of 2–13.5 µm when the core diameter of the fiber was ≤ 10 µ m . Under pumping at 5 µm, a highly coherent SC generation in the range of 2–13.2 µm was generated in a 16-cm-long AS-MOF with core diameter of 9.8 µm.

Ultraflat, broadband, and highly coherent supercontinuum generation in all-solid microstructured optical fibers with all-normal dispersion

High flatness, wide bandwidth, and high-coherence properties of supercontinuum (SC) generation in fibers are crucial in many applications. It is challenging to achieve SC spectra in a combination of the properties, since special dispersion profiles are required, especially when pump pulses with duration over 100 fs are employed. We propose an all-solid microstructured fiber composed only of hexagonal glass elements. The optimized fiber possesses an ultraflat all-normal dispersion profile, covering a wide wavelength interval of approximately 1.55 μm. An SC spectrum spanning from approximately 1030 to 2030 nm (corresponding to nearly one octave) with flatness <3 dB is numerically generated in the fiber with 200 fs pump pulses at 1.55 μm. The results indicate that the broadband ultraflat SC sources can be all-fiber and miniaturized due to commercially achievable 200-fs fiber lasers. Moreover, the SC pulses feature high coherence and a single pulse in the time domain, which can be compressed to 13.9-fs pulses with high quality even for simple linear chirp compensation. The Fourier-limited pulse duration of the spectrum is 3.19 fs, corresponding to only 0.62 optical cycles.

Asterisk-shaped microstructured fiber for an octave coherent supercontinuum in a sub-picosecond region.

We selected two thermally matched silicate glasses with fair refractive index contrast and developed an asterisk-shaped all-solid microstructured optical fiber. The fiber presents a low, ultra-flat, and all-normal dispersion in a wide wavelength range, allowing for the generation of an octave-spanning coherent supercontinuum (SC) in a 20dB dynamic range with 0.5ps pump pulses at 1.55μm. This result improves pump pulse duration that is only ∼100 fs, related to the broadband and highly coherent SC generation in fibers with all-normal dispersion. This enables broadband SC sources with all-fiber, high-power, and highly coherent properties.

Scalable waveguide design for three-level operation in Neodymium doped fiber laser.

We have constructed a double clad neodymium doped fiber laser operating on the three-level 4F3/2→4I9/2 transition. The laser has produced 11.5 W at 925 nm with 55% slope efficiency when pumped at 808 nm, comparable to the best previous results for a double-clad fiber configuration on this transition. Higher power pumping with both 808 nm and 880 nm sources resulted in an output of 27 W, albeit at lower slope efficiency. In both cases, output power was limited by available pump, indicating the potential for further power scaling. To suppress the stronger four-level 4F3/2→4I11/2 transition we developed a waveguide that provides spectral filtering distributed along the length of the fiber, based on an all-solid micro-structured optical fiber design, with resonant inclusions creating a leakage path to the cladding. The waveguide supports large mode areas and provides strong suppression at selectable wavelength bands, thus easing the restrictions on core and cladding sizes that limited power scaling of previous approaches.

Optical fiber microstructuration for strengthening single-mode laser operation in high power regime

We propose an in-depth investigation of all-solid microstructured optical fibers for the development of very large mode area (VLMA) fiber lasers. The inner cladding microstructure of these VLMA fibers is carefully optimized in order to get a robust single-mode laser operation in the high power regime. We describe the numerical approach used to devise a novel kind of fiber structures, the core of which should be larger than 50 μm while showing an improved single-mode emission compared to that of the state-of-the-art large pitch fibers. With the aim of overpassing the limitations of chemical vapor deposition techniques, we opted for a manufacturing process called Repusil, based on the sintering and vitrification of doped powders. Then, our opto-geometrical considerations result from the optical properties offered by this method and the use of the stack and draw. Finally, we present our very first fabrication for the proposed all-solid microstructured fibers in which a laser emission of 52 W in a continuous wave regime was obtained.

All-solid all-chalcogenide microstructured optical fiber

The realization of an all-solid microstructured optical fiber based on chalcogenide glasses was achieved. The fiber presents As(2)S(3) inclusions selected as low refractive index material (n = 2.4) embedded in a As(38)Se(62) glass matrix (n = 2.8). The single mode regime of the fiber was demonstrated both theoretically by multipole method calculations and experimentally by near field measurements. Optical transmission measurements of the microstructured fiber and single index fibers made of the initial glasses reveal an excess of losses as high as 6-7 dB/m. This excess is not due to the guide geometry but can be explained by the presence of defects in the glass interface regions.

Optical properties of all-solid microstructured optical fibers

In this Letter, we study optical properties of all-solid microstructured optical fiber made of soft glass. Such fibers have various interesting features including good geometrical stability, low fundamental transmission losses, high Kerr nonlinearity, and large solubility of rare-earth ions. By investigating transmission mechanism, mode structure, and numerical aperture of the fibers and confronting the results with theoretical calculations we demonstrate that the fibers have optical properties similar to those observed in air-silica microstructured optical fibers. This makes the all-solid soft-glass microstructured fibers very attractive for many potential applications. Full Text: PDF References J. R. Hayes, J. C. Flanagan, T. M. Monro, D. J. Richardson, P. Grunewald, and R. Allott, "Square core jecketed air-clad fiber", Optics Express, 14(22):10345-10350, 2006 CrossRef N. A. Issa, "High numerical aperture in multimode microstructured optical fibers", Applied Optics, 43(33):6191-6197, 2004 CrossRef M. Antkowiak, R. Kotynski, T. Nasilowski, P. Lesiak, J. Wojcik, W. Urbanczyk, F. Berghmans, and H. Thienpont, "Phase and group modal birefringence of triple-defect photonic crystal fibres", Journal of Optics A: Pure and Applied Optics, 7(12):763, 2005 CrossRef W. Reeves, J. Knight, P. St. Russell, and P. Roberts, "Demonstration of ultra-flattened dispersion in photonic crystal fibers", Optics Express, 10(14):609-613, 2002 CrossRef C. Martelli, J. Canning, B. Gibson, and S. Huntington, "Bend loss in structured optical fibres", Optics Express, 15(26):17639-17644, 2007 CrossRef T. A. Birks, J. C. Knight, and P. St. Russell, "Endlessly single-mode photonic crystal fiber", Optics Letters, 22(13):961-963, 1997 CrossRef L. Rindorf, J. B. Jensen, M. Dufva, L. H. Pedersen, P. E. Hoiby, and O. Bang, "Photonic crystal fiber long-period gratings for biochemical sensing", Optics Express, 14(18):8224-8231, 2006 CrossRef R. Buczynski, D. Pysz, I. Kujawa, J. Korzeniowski, T. Martynkien. F. Berghmans, H. Thienpont, and R. Stepien, "Supercontinuum generation with microstructured fibers made of soft glass", Photonics Letters of Poland, 1(3):109-111, 2009 CrossRef M. Nielsen, C. Jacobsen, N. Mortensen, J. Folkenberg, and H. Simonsen, "Low-loss photonic crystal fibers for transmission systems and their dispersion properties", Optics Express, 12(7):1372-1376, 2004 CrossRef W. Wadsworth, R. Percival, G. Bouwmans, J. Knight, and P. Russell, "High power air-clad photonic crystal fibre laser", Optics Express, 11(1):48-53, 2003 CrossRef X. Feng, T. M. Monro, P. Petropoulos, V. Finazzi. and D. Hewak, "Solid microstructured optical fiber", Optics Express, 11(18):2225-2230, 2003 CrossRef R. Buczynski, I. Kujawa, R. Kasztelanic, D. Pysz, K. Borzycki, F. Berghmans, H. Thienpond, and R. Stepien, "Supercontinuum generation in all-solid photonic crystal fiber with low index core", Laser Physics, 22(4):784-790, 2012 CrossRef M. Grabka, S. Pustelny, P. Mergo, and W. Gawlik, "Application of continuous wavelet transform for determination of fiber birefringence", Optics Express, 20(13):13878-13885, 2012 CrossRef M. Grabka, B. Wajnchold, S. Pustelny, W. Gawlik, K. Skorupski, and P. Mergo, "Experimental and theoretical study of light propagation in suspended-core optical fibre", Acta Physica Polonica A, 118(6):1127-1132, 2010 DirectLink M. J. F. Digonnet, Hyang Kyun Kim, G. S. Kino, and Shanhui Fan, "Understanding Air-Core Photonic-Bandgap Fibers: Analogy to Conventional Fibers", Journal of Lightwave Technology, 23(12):4169-4177, 2005 CrossRef H. Ebendorff-Heidepriem, R. G. Moore, T. M. Monro, "Progress in the fabrication of the next-generation soft glass microstructured optical fibers", AIP Conference Proceedings, 1055(1):95-98, 2008 CrossRef

A Bragg-like chirped clad all-solid microstructured optical fiber with ultra-wide bandwidth for short pulse delivery and pulse reshaping

Chirped cladding is proposed as a novel tailoring tool to simultaneously attain wider transmission window and reduced temporal dispersion in an all-solid Bragg-like microstructured optical fiber as compared to its perfectly periodic cladding counterpart. This design route for photonic bandgap microstructured fibers could be exploited as an additional degree of freedom for bandgap engineering. A suitably chirped clad fiber could be gainfully exploited to deliver femto-second pulse with ultra wide bandwidth. Further, generation of self-similar parabolic profile pulse is demonstrated by simulating propagation of an input Gaussian pulse through a 2 m long sample of such a linearly tapered Bragg like fiber.