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Volume 34, Issue 1
Displaying 1-15 of 15 articles from this issue
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Noriaki ONODERA2006 Volume 34 Issue 1 Pages 5-6
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (247K) -
Osamu TOHYAMA, Hideaki ITOH, Syun-ichiro YAMAGUCHI2006 Volume 34 Issue 1 Pages 7-11
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDramatic advances in research and development on photonic crystal fibers have created new properties that have not been achievable using conventional fibers. Photonic crystal fibers have many fascinating features. The very high relative refractive index between the fiber core and air hole cladding enables several prominent properties, notably endlessly single-mode operation, high nonlinearity, wide-ranging dispersion management, and the ability to maintain high polarization. The processes involved in manufacturing photonic crystal fibers are quite different from those used to manufacture conventional fibers, largely due to the profusion of air holes in the silica glass that comprises photonic crystal fibers. Our research group has optimized the technology to manufacture photonic crystals with the required optical characteristics. This paper describes the manufacturing technology we have developed to produce photonic crystal fibers with low attenuation and high reliability.View full abstractDownload PDF (3633K) -
Kyozo TSUJIKAWA2006 Volume 34 Issue 1 Pages 12-16
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSNew types of optical fiber with a silica-air microstructure, such as photonic crystal fiber (PCF), hole-assisted fiber (HAF) and photonic bandgap fiber (PBGF), have received increasing attention because of their novel guiding properties. In particular, PCF is very attractive as a transmission medium for future networks, because it can be endlessly single-mode, and its chromatic dispersion can be tailored. This paper mainly focuses on recent progress in loss reduction in photonic crystal fiber.View full abstractDownload PDF (8189K) -
Kazuhide NAKAJIMA, Takashi MATSUI2006 Volume 34 Issue 1 Pages 17-21
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThis paper reviews recent progress in Photonic Crystal Fiber (PCF) with flattened dispersion characteristics. We describe the chromatic dispersion controllability in various PCFs taking both uniform and non-uniform air hole structures into consideration. We also review recent reports on a highly nonlinear medium that utilizes the dispersion-flattened PCF. Moreover, we introduce the characteristics of a novel dispersion-flattened PCF, which has the potential to become a transmission medium for wideband and high-bit-rate optical communication. We show numerically that the proposed double air cladding structure successfully achieves flat medial dispersion characteristics as well as an enlarged effective area and low confinement loss. Finally, we point out that full controllability of the chromatic dispersion, effective area and confinement loss, along with the fabrication technique, will be key issues to make further progress with the dispersion-flattened PCF.View full abstractDownload PDF (1033K) -
Hirokazu KUBOTA2006 Volume 34 Issue 1 Pages 22-25
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSPolarization maintaining fiber is optical fiber in which the polarization planes of lightwaves launched into the fiber are maintained during propagation. The degree of modal birefringence is one of the most important characteristics of polarization maintaining fiber. A high degree of modal birefringence, which guarantees good polarization maintaining properties, is easily obtained with photonic crystal fiber. This paper reviews polarization maintaining photonic crystal fiber in terms of modal birefringence.View full abstractDownload PDF (3884K) -
Kazumasa OSONO, Bing YAO, Masao TACHIKURA2006 Volume 34 Issue 1 Pages 26-30
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA holey fiber has been developed that has an extremely low bending loss (less than 0.01dB/turn) at a bending diameter of 10mm. Six air holes around the core lower the effective cladding index and as a result those confine the signal light within the core better compared with conventional fibers. The optical characteristics, fiber-joint characteristics, and reliability of this holey fiber were investigated. An optical curl cord developed utilizing the very low bending loss of this holey fiber was found to have characteristics suitable for indoor wiring of FTTH.View full abstractDownload PDF (6483K) -
Masanori KOSHIBA, Kunimasa SAITOH2006 Volume 34 Issue 1 Pages 31-36
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSPhotonic crystal fibers (PCFs) have recently attracted considerable attention because of their interesting and unconventional optical properties. Particularly, multi-core photonic crystal fibers (MCPCFs) have several potential advantages making them excellent candidates for applications such as, wavelength multiplexerdemultiplexer (MUX-DEMUX) devices, polarization splitters (PSs), dispersion-compensating fibers (DCFs), curvature sensors, vector bend sensors, Doppler difference velocimeters, phase-locked high-power lasers, optical frequency comb generators, and so on. In this paper MCPCF-structures and some potential applications are reviewed, and in addition design principles for constructing wavelength MUX-DEMUX, PS, DCF based on, two-core, three-core, and dual-concentric-core PCFs respectively, are introduced.View full abstractDownload PDF (1182K) -
Satoki KAWANISHI2006 Volume 34 Issue 1 Pages 37-41
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSSupercontinum generation techniques based on photonic crystal Hbers (PCFs) in the 1550 nm wavelength region are reviewed. A PCF has an array of air holes surrounding a core region. PCF has several benefits compared to conventional single mode fibers including single mode operation in broad wavelength region, greater freedom in fiber design, large nonlinearity, and easily achieved polarization maintaining characteristics. This paper describes recent progress on the design of PCFs for supercontinuum generation in the 1550 nm wavelength region together with experimental results. The potential of the PCFs is discussed with reference to the next generation high performance optical networks.View full abstractDownload PDF (3620K) -
Kuniharu HIMENO2006 Volume 34 Issue 1 Pages 42-46
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSArc-fusion splicing techniques for photonic crystal fibers (PCFs) are introduced and reviewed. Basics of arcfusion splicing for optical fibers, such as splice losses and an arc-fusion splicer, are reviewed. Experimental results of arc-fusion splicing for a hole-assisted PCF and a total internal reflection (TIR) PCF, which has been investigated by the author's research team, are introduced.View full abstractDownload PDF (10034K) -
Kazi S. ABEDIN2006 Volume 34 Issue 1 Pages 47-51
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe demonstrate harmonically mode-locked, dispersion-managed, polarization-maintaining erbium fiber lasers that use photonic crystal fiber (PCF) for nonlinear pulse compression. The high nonlinearity and large anomalous dispersion of the PCF resulted in significant reduction in the cavity length and increased long-term stability. The laser cavity, only 36-m-long, yielded stable picosecond pulses at 10- and 40-GHz repetition rates, with supermode noise suppression of over 60dB.View full abstractDownload PDF (3341K) -
Kouji BANDOU, Katsumi HIRAMATSU, Toshio KURASHIMA, Shigeru TOMITA, Tad ...2006 Volume 34 Issue 1 Pages 52-56
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSHole-assisted fiber has a conventional refractive index core and several air holes in the cladding around the core. This fiber has no bending loss at a bending radius of 5 mm. We have designed and fabricated an optical fiber curl cord as an application of this fiber. The wiring length of this cord can be flexibly adjusted because the curled part is capable of stretching and then contracting. We confirmed that our optical fiber curl cord has good characteristics by performing tests and evaluations including a failure probability calculation, flame resistance tests, and crush tests, on the assumption that the cord would be used in home networks. We also developed a bendable type SC connector with this type of fiber. This connector is designed to achieve optical wiring workability, safety, and a good appearance. We also obtained good results in splice loss, repeated bending and heat cycle tests with our bendable type SC connector.View full abstractDownload PDF (3548K) -
Makoto HIRASAWA, Yoshihiko MATSUOKA, Yuko KIZUKA, Takashi INOUE2006 Volume 34 Issue 1 Pages 57-61
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe effects of condensers on laser micro drilling in stainless steel foil were studied using second or fourth harmonic light of a nanosecond pulsed Nd: YAG laser, in order to clarify the features of an axially condensed beam. The through holes several ±m in diameter could be drilled by adjusting the work distance precisely, though a conventional convex lens was used. However, the diameters were doubled by only a 0.1 mm change in the work distance. When the drilling was performed by an axially condensed beam using an axicon, the through hole diameters of several ±m were not changed, even though the work distances were changed ± 5mm. The through holes with an aspect ratio of about 10 and a diameter of about 1 ±m could be drilled using the fourth harmonic light and a DOE axicon.View full abstractDownload PDF (769K) -
Tatsuki OKAMOTO, Kazutoshi MORIKAWA, Atsuhiro SONO, Yukio SATO, Junich ...2006 Volume 34 Issue 1 Pages 62-66
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe have developed a new optical system that transforms the circle profile beam generated with near Gaussian intensity distribution by a pulsed green laser (second harmonics of a Q-switched Nd: YAG laser) into a lineprofile beam. This transformed beam has uniform distribution to within 5% in the longitudinal direction, and is about 100 mm long and 40 μm wide. In the width direction, the laser beam is focused to the limited M2 value. For homogenization in the longitudinal direction, we employ a one dimensionnal waveguide plate type homogenizer. The laser beam is divided by waveguide plates, and the divided beams are overlapped on the surface of the works. We successfully reduced interference fringes by increasing the fixed optical pass difference beyond the inherent time and coherent length for every divided pair of adjacent beams under a controlled space coherent length.View full abstractDownload PDF (3676K) -
Kazuhiko SUMIMURA, Hidetsugu YOSHIDA, Hajime OKADA, Hisanori FUJITA, M ...2006 Volume 34 Issue 1 Pages 67-70
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSAll fiber type nanosecond pulse ring laser oscillator consists of simple components. In the cavity, active or passive components such as an acousto-optic modulator or saturable absorber were not inserted. The fiber laser can produce 1-ns pulse train without the devices for polarization control and compensation of birefringence. Nanosecond fiber pulse laser has a possibility that can be widely applied to industry and scientific tool.View full abstractDownload PDF (568K) -
Yoshinobu MAEDA, Yoshinobu KONDO2006 Volume 34 Issue 1 Pages 71-75
Published: January 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSAn all-optical inverted triode based on cross-gain modulation was realized in an InGaAsP-InP semiconductor optical amplifier. The output power ranged from 0.1 to 3 mW when the average control power was varied from 0.01 to 0.5 mW at the input average power of 2mW. Therefore, the output-input characteristics can be changed dynamically by low control powers. The output modulation degree was retained at around 70% over a wide control power range of 0.01 - 0.1 mW. The dependence of the output modulation degree on the input signal frequency indicates that the device can be operated with an input signal frequency up to 3 GHz. Because of its characteristics, this device can become a key component in future all- optical signal processing.View full abstractDownload PDF (789K)
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