scispace - formally typeset
Search or ask a question
Proceedings ArticleDOI

Design of octagonal core micro-cladding leakage channel fiber with low bending loss

M. Valliammai1, J. Mohanraj1, S. Sivabalan1, K. Senthilnathan1, P. Rameshbabu1 
01 Dec 2015-pp 1-4
TL;DR: In this article, a large mode area (LMA) micro-cladding leakage channel fiber (LCF) with an octagonal shaped core for 1.064 μm wavelength is proposed.
Abstract: We design a large mode area (LMA) micro-cladding leakage channel fiber (LCF) with an octagonal shaped core for 1.064 μm wavelength. Our numerical simulation shows that very low bending loss at small bend radius can be achieved by scaling up the micro-cladding elements of LCF. Further, the proposed fiber exhibits novel properties such as large effective area (1287 μm2) and very low bending loss of 5.58 × 10−3 dB/m for a bending radius of 5 cm. These interesting properties of the proposed LCF pave the way for developing a compact high power fiber laser and amplifier.
References
More filters
Journal ArticleDOI
TL;DR: An effective-index model confirms that an all-silica optical fiber made by embedding a central core in a two-dimensional photonic crystal with a micrometer-spaced hexagonal array of air holes can be single mode for any wavelength.
Abstract: We made an all-silica optical fiber by embedding a central core in a two-dimensional photonic crystal with a micrometer-spaced hexagonal array of air holes. An effective-index model confirms that such a fiber can be single mode for any wavelength. Its useful single-mode range within the transparency window of silica, although wide, is ultimately bounded by a bend-loss edge at short wavelengths as well as at long wavelengths.

2,905 citations


"Design of octagonal core micro-clad..." refers background in this paper

  • ...In order to maintain the endlessly single-mode (ESM) operation [5], the LMA photonic crystal fibers (PCFs) have been proposed and its NA is as low as 0....

    [...]

  • ...Recently, the several fiber structures such as chirally coupled core fiber [8], bragg fiber [15], photonic band gap fiber [14], photonic quasi-crystal fiber [7] and leakage channel fiber (LCF) [9], [10] have been proposed to extend the regime of single-mode operation [5] and enhance the effective area (Aeff ) of fundamental mode (FM) with low-NA....

    [...]

Journal ArticleDOI
TL;DR: In this article, an improved curvature loss formula for optical waveguides is presented, which is shown to accurately predict the bend loss of both single-mode and multimode fibers.
Abstract: This paper presents an improved curvature loss formula for optical waveguides, which is shown to accurately predict the bend loss of both single-mode and multimode fibers. The formula expands upon a previous formula derived by Marcuse, greatly improving its accuracy for the case of multimode fiber. Also presented are the results of bent fiber simulations using the beam propagation method (BPM), and experimental measurements of bend loss. Agreement among simulation, formula and measurement support the validity of both theoretical methods. BPM simulations showed that the lowest order modes of the bent fiber were reduced to their linearly polarized constituents prior to the onset of significant bend loss. This implies that certain LP mode orientations should propagate with much lower loss than previously expected, and should impact the mode stripping ability of bent large mode area fibers, as employed in fiber lasers and amplifiers.

327 citations

Journal ArticleDOI
TL;DR: In this paper, a leakage channel fiber is designed to create large leakage loss for higher-order modes, while maintaining negligible transmission loss for the fundamental mode, which can be used for designing optical fibers with large effective area, which supports robust fundamental mode propagation.
Abstract: Leakage channel fibers, where few air holes form a core, can be precisely engineered to create large leakage loss for higher-order modes, while maintaining negligible transmission loss for the fundamental mode. This unique property can be used for designing optical fibers with large effective area, which supports robust fundamental mode propagation. The large air holes in the design also enable the optical fibers to be bend resistant. The principles of design and operation regime are outlined, demonstrating the potential of this approach for optical fibers that propagate a fundamental mode in core diameter exceeding 100 μm. Performance of a fabricated passive leakage channel fiber, an ytterbium-doped double-clad leakage channel fiber, and an ytterbium-doped polarization-maintaining double-clad leakage channel fiber are also discussed.

190 citations


"Design of octagonal core micro-clad..." refers background in this paper

  • ...Recently, the several fiber structures such as chirally coupled core fiber [8], bragg fiber [15], photonic band gap fiber [14], photonic quasi-crystal fiber [7] and leakage channel fiber (LCF) [9], [10] have been proposed to extend the regime of single-mode operation [5] and enhance the effective area (Aeff ) of fundamental mode (FM) with low-NA....

    [...]

Journal ArticleDOI
TL;DR: Experimental characterization of 55 µm-core CCC fibers based on spatially and spectrally resolved broadband measurements (S(2) technique) shows that modal performance of these large core fibers well exceeds that of standard 20 μm core step-index large mode area fibers.
Abstract: In this paper, we report an advance in increasing core size of effective single-mode chirally-coupled-core (CCC) Ge-doped and Yb-doped double-clad fibers into 55µm to 60µm range, and experimentally demonstrate their robust single-mode performance. Theoretical and numerical description of CCC fibers structures with multiple side cores and polygon-shaped central core is consistent with experimental results. Detailed experimental characterization of 55µm-core CCC fibers based on spatially and spectrally resolved broadband measurements (S2 technique) shows that modal performance of these large core fibers well exceeds that of standard 20μm core step-index large mode area fibers.

156 citations


"Design of octagonal core micro-clad..." refers background in this paper

  • ...Recently, the several fiber structures such as chirally coupled core fiber [8], bragg fiber [15], photonic band gap fiber [14], photonic quasi-crystal fiber [7] and leakage channel fiber (LCF) [9], [10] have been proposed to extend the regime of single-mode operation [5] and enhance the effective area (Aeff ) of fundamental mode (FM) with low-NA....

    [...]

Journal ArticleDOI
TL;DR: Leakage channel fibers (LCF) have demonstrated their ability to significantly extend the effective mode area of a fundamental mode while maintaining robust single-mode operation as discussed by the authors, and have been designed to have strong built-in mode filtering that effectively suppresses the propagation of all higher order modes while keeping fundamental-mode loss to a minimum, and, therefore, effectively extending the regime of single mode operation.
Abstract: Leakage channel fibers (LCFs) have demonstrated their ability to significantly extend the effective mode area of a fundamental mode while maintaining robust single-mode operation. These fibers are designed to have strong built-in mode filtering that effectively suppresses the propagation of all higher order modes while keeping fundamental-mode loss to a minimum, and, therefore, effectively extending the regime of single-mode operation. Recently, all-glass LCFs have been demonstrated as a significant improvement over designs with air holes. These all-glass LCFs can not only be manufactured with much improved consistence and uniformity, but can also be handled and used as conventional fibers. More importantly, mode distortions from collapse of air holes in photonic crystal fibers during splicing and other endface treatments are largely eliminated. We will review some of the recent progress in this area.

112 citations


"Design of octagonal core micro-clad..." refers background in this paper

  • ...In addition, the above discussed LCFs suffered in complex material design space which always depends on large pitch value [6], [11]....

    [...]