1,720,995 research outputs found
Structural and optical characterisation of holey fibres using scanning probe microscopy
No full textAn investigation of a holey fibre using scanning probe microscopy techniques, which the authors believe is the first such investigation, is presented. Atomic force microscopy images provide knowledge of the fibre structure without the artefacts associated with scanning electron microscopy imaging. A tapered fibre scanning near-field optical microscopy probe has been used to investigate holey fibre modes at 785 nm
Assorted core air-clad fibre
No full textAn optical fibre containing a selection of,independently addressable air-clad cores with different dimensions is presented. The intrinsic properties of such an assorted core fibre are studied and potential applications are reviewed The physical dimensions required for guidance at various wavelengths are explored
Soliton transmission and supercontinuum generation in holey fiber, using a diode pumped Ytterbium fiber source
No full textWe report linear dispersion compensation, soliton pulse formation, soliton compression, and ultra-broad supercontinuum generation in a holey fiber with anomalous dispersion at wavelengths above 800nm. The holey fiber was seeded with ultrashort pulses from a diode pumped, Ytterbium (Yb)-doped fiber source operating at 1.06 mum. The results highlight the compatibility of the rapidly developing holey fiber technology with short pulse Yb-doped fiber lasers for wide application. (C) 2002 Optical Society of America
Raman effects in a highly nonlinear holey fiber: amplification and modulation
No full textWe experimentally demonstrate that a short length of highly nonlinear holey fiber (HF) can be used for strong L+-band (1610-1640-nm) Raman amplification and ultrafast signal modulation. We use a pure silica HF with an effective area of just 2.85 mum(2) at 1550 nm, which yields an effective nonlinearity similar to15 times higher than in conventional silica dispersion-shifted fiber. Using a 75-m length of this fiber, we obtained internal Raman gains of more than 42 dB and a noise figure of similar to6 dB under a forward single-pump scheme, and the Raman gain coefficient was experimentally estimated to be 7.6 X 10(14) m/W. Also. an 11-dB signal extinction ratio in a Raman-induced all-optical modulation experiment was achieved with the same fiber. (C) 2002 Optical Society of America
Sensing with microstructured optical fibres
No full textThe optical and geometrical properties of microstructured optical fibres present new alternatives for a range of sensing applications. We present the design criteria for achieving significant overlap between the light guided in the fibre and the air holes and hence for producing efficient evanescent field devices. In addition, the novel dispersive properties combined with the tight mode confinement possible in holey fibres make ultra-broadband single-mode sources and new source wavelengths a possibility. Microstructuring technology can be readily extended to form multiple-core fibres, which have applications in bend/deformation sensing. Finally, fibre-based atom waveguides could ultimately be used for rotational or gravitational sensing
Investigation of Brillouin effects in small-core holey optical fiber: lasing and scattering
No full textWe demonstrate for what is believed to be the first time a Brillouin laser based on a holey fiber (HF). Using a simple Fabry-Perot resonator scheme containing a 73.5-m-long highly nonlinear HF with an effective area of 2.85 mum(2), we obtain a threshold of 125 mW and a slope efficiency of similar to70%. Stimulated and spontaneous Brillouin scattering effects are investigated in the HF, and we show that the high lasing threshold is due mainly to reduction of the effective gain coefficient caused by structural nonuniformity along the fiber length. (C) 2002 Optical Society of America
Polarization mode dispersion reduction in spun large mode area silica holey fibres
No full textWe report the fabrication of the first spun holey optical fibre. Our experiments show that the complex air/glass transverse structure can be retained when the preform is spun during the fibre drawing process. Measurements of differential group delay (DGD) confirm that significant reductions in polarization mode dispersion (PMD) can be readily achieved using this approach. (C) 2004 Optical Society of America
Four-wave mixing based 10-Gb/s tunable wavelength conversion using a holey fiber with a high SBS threshold
No full textWe demonstrate a four-wave-mixing based wavelength converter using a 15-m highly nonlinear holey fiber (HF) with a high stimulated Brillouin scattering (SBS) threshold. Error-free efficient wavelength conversion of 10-Gb/s nonreturn-to-zero signal over a similar to10-nm bandwidth is reliably achieved. Our 15-m HF has a nonlinearity coefficient gamma similar to 70(+/-10) W-1. km(-1) and an SBS threshold of more than 130 mW. The high SBS threshold is achieved by applying structural variation to the HF along its length during the fabrication process. No modulational-instability-induced intensity noise on the converted signals is observed due to the normal dispersion of the HF
A tunable WDM wavelength converter based on cross-phase modulation effects in normal dispersion holey fiber
No full textWe demonstrate a tunable wavelength-division-multiplexing wavelength converter based on cross-phase modulation in just 5.8 no of highly nonlinear normal dispersion holey fiber (HF) and incorporating a precise compression-tuned apodized fiber-grating filter. We achieve both error-free and penalty-free 10-Gb/s wavelength conversion over a similar to15-nm bandwidth. The short device length and correspondingly reduced pulse walkoff effect ensures a constant wavelength-converted signal pulsewidth across the full tuning range. The use of HF with normal dispersion eliminates the coherence-degradation related intensity noise previously observed in experiments employing anomalously dispersive HF
2R-regenerative all-optical switch based on a highly nonlinear holey fiber
No full textWe report the fabrication of a highly nonlinear holey fiber made from pure silica with an effective area of just similar to2.8 mum(2) at 1550 run. We believe this to be the smallest effective area yet measured for a holey fiber at 1550 nm. We also report the operation of a 2R regenerative optical switch based on just 3.3 m of the fiber that is shown to have 30 times the nonlinear figure of merit of previous devices based on dispersion-shifted fiber. (C) 2001 Optical Society of America
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