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Kunimasa Saitoh – One of the best experts on this subject based on the ideXlab platform.
design of three spatial mode ring core fiberJournal of Lightwave Technology, 2014Co-Authors: Motoki Kasahara, Kunimasa Saitoh, Takashi Matsui, Kyozo Tsujikawa, Taiji Sakamoto, Nobutomo Hanzawa, Fumihiko YamamotoAbstract:
We investigate the fiber parameters which meet the design conditions for effectively three-spatial-mode transmission and low Bending Loss in a ring-core fiber for mode-division multiplexing transmission. We also clarify the effective area and the difference of the effective index while satisfying the design conditions.
effectively single mode all solid photonic bandgap fiber with large effective area and low Bending Loss for compact high power all fiber lasersOptics Express, 2012Co-Authors: Masahiro Kashiwagi, Kunimasa Saitoh, Shoichiro Matsuo, Katsuhiro Takenaga, Shoji Tanigawa, Munehisa FujimakiAbstract:
An effectively single-mode all-solid photonic bandgap fiber with large effective area and low Bending Loss for compact high-power all-fiber lasers is fully investigated. The pitch dependencies of effective area, Bending Loss, and effectively single-mode operation are discussed numerically and experimentally. The calculation results indicate that an effectively single-mode all-solid photonic bandgap fiber with an effective area of more than 500 μm2 and a Bending Loss of less than 0.1 dB/m at a Bending radius of 10 cm can be realized by choosing optimum fiber parameters. In a fabricated effectively single-mode all-solid photonic bandgap fiber with 48.0 μm core, the effective area of 712 μm2, the effectively single-mode operation, and the Bending Loss of less than 0.1 dB/m at a Bending radius of 10 cm are achieved simultaneously at 1064 nm.
low Bending Loss and effectively single mode all solid photonic bandgap fiber with an effective area of 650 μm 2Optics Letters, 2012Co-Authors: Masahiro Kashiwagi, Kunimasa Saitoh, Shoichiro Matsuo, Katsuhiro Takenaga, Shoji Tanigawa, Munehisa FujimakiAbstract:
A large-mode-area all-solid photonic bandgap fiber with a seven-cell core and
five high-index rod rings is investigated. Numerical simulations show that an
effective area of more than 500 μm2, a Bending Loss
of less than 0.1 dB/m at a Bending radius of 10 cm and
effectively single-mode operation can be achieved simultaneously. A core diameter of
44.8 μm and an effective area of 650 μm2
at 1064 nm are achieved in a fabricated fiber. Bending Loss at 1064 nm is
0.09 dB/m at a Bending radius of 7 cm. Effectively single-mode
operation is also realized at a Bending radius of 10 cm.
Masanori Koshiba – One of the best experts on this subject based on the ideXlab platform.
design principle for realizing low Bending Losses in all solid photonic bandgap fibersJournal of Lightwave Technology, 2011Co-Authors: Tadashi Murao, Koyuru Nagao, Kunimasa Saitoh, Masanori KoshibaAbstract:
In this paper, the structural dependence of factor which mainly affects a Bending Loss property is theoretically investigated in all-solid photonic bandgap fibers (PBGFs). A design principle for realizing low Bending Losses is successfully figured out for the first-order photonic bandgap (PBG). In particular, one of the origins which causes the variation of Bending Loss property for each structural parameter is identified. In addition, we show that exploitation of a large pitch relative to a rod diameter, aiming to realize a large-mode area (LMA) structure, leads to a significant degradation of the Bending Loss property. Moreover, it is demonstrated that a V-value which is proposed for all-solid PBGFs is also reduced significantly for the LMA condition. The origin of the degradation is attributed to the newly-excited Bloch state which determines the second-order PBG edge.
investigation on multi core fibers with large aeff and low micro Bending LossOptics Express, 2011Co-Authors: Katsunori Imamura, Kunimasa Saitoh, Yukihiro Tsuchida, Kazunori Mukasa, Ryuichi Sugizaki, Masanori KoshibaAbstract:
To realize large effective area (Aeff) multi-core fibers (MCFs), the design to suppress the cross-talk and the influence of the cladding diameter on the micro Bending Loss were investigated. As a result, the MCFs with large Aeff over 100 μm2 and low micro Bending Loss were successfully fabricated. The results indicate the importance of fiber design to realize large Aeff MCFs including fiber diameters, which largely affect the micro Bending Loss property. Additionally, MCF with large Aeff, low attenuation Loss and suppressed cross-talk was successfully realized by optimizing the fiber design. The cross-talk properties could be estimated by the simulation based on the coupling power theory taking the influences of the longitudinal fluctuation of core diameter into account.
multiple resonant coupling mechanism for suppression of higher order modes in all solid photonic bandgap fibers with heterostructured claddingOptics Express, 2011Co-Authors: Tadashi Murao, Kunimasa Saitoh, Masanori KoshibaAbstract:
In this paper, we propose a novel mechanism for suppression of higher-order modes (HOMs), namely multiple resonant coupling, in all-solid photonic bandgap fibers (PBGFs) with effectively large core diameters. In an analogy to the well-known tight-binding theory in solid-state physics, multiple anti-resonant reflecting optical waveguide (ARROW) modes bound in designedly arranged defects in the cladding make up Bloch states and resultant photonic bands with a finite effective-index width, which contribute to the suppression of HOMs. In particular, contrary to the conventional method for the HOM suppression using the index-matching of the HOMs in the core of the PBGF and the defect mode arranged in the cladding, the proposed mechanism guarantees a broadband HOM suppression without a precise structural design. This effect is explained by the multiple resonant coupling, as well as an enhanced confinement Loss mechanism which occurs near the condition satisfying the multiple resonant coupling. Moreover, we show that the proposed structure exhibits a lower Bending Loss characteristic when compared to the conventional all-solid PBGFs. The simultaneous realization of the single-mode operation and the low Bending Loss property is due to the novel cladding concept named as heterostructured cladding. The proposed structure also resolves the issue for the increased confinement Loss property in the first-order photonic bandgap (PBG) at the same time.
Pramod R Wateka – One of the best experts on this subject based on the ideXlab platform.
optimized design of trenched optical fiber for ultralow Bending Loss at 5 mm of Bending diameterApplied Optics, 2011Co-Authors: Pramod R WatekaAbstract:
We propose a bend-insensitive optical fiber with optimized design for the ultralow Bending Loss at 1550 nm for 5 mm of Bending diameter, with a wide cutoff wavelength tolerance.
near zero Bending Loss in a double trenched bend insensitive optical fiber at 1550 nmOptics Express, 2009Co-Authors: Pramod R WatekaAbstract:
We have developed a new single-mode optical fiber (SMF) which exhibits ultra low bend sensitivity over a wide communication band. The measured mean Bending Loss at 1550 nm was about 0.0095 dB for a loop of 10 mm diameter.
design and development of a trenched optical fiber with ultra low Bending LossOptics Express, 2009Co-Authors: Pramod R WatekaAbstract:
We have designed and experimentally demonstrated a single mode optical fiber with a very low Bending Loss of about 0.014 dB/loop at 1550 nm for a Bending radius of 5 mm.