Km Of Non-dispersion Shifted Fibre Research Articles

High-temperature and high-speed operation of a 1.3-/spl mu/m uncooled InGaAsP-InP DFB laser

1.3-μm uncooled InGaAsP-InP loss-coupled distributed feedback lasers operating over 10 Gb/s and at 85/spl deg/C were successfully fabricated. In order to achieve high-speed and high-temperature operation simultaneously, the following are thoroughly investigated: modulation-doped and strain-compensated multiple-quantum-well active layers, Fe-doped buried-heterostructure, coupling coefficient of loss-coupled grating, detuning lasing wavelength from the gain peak, and facet coatings. The authors also demonstrate 10 Gb/s transmission with negligible dispersion power penalty over 20 km of nondispersion-shifted fiber at 10 Gb/s for temperatures ranging from 25/spl deg/C to 85/spl deg/C.

A low-cost WDM source with an ASE injected Fabry-Perot semiconductor laser

We propose and demonstrate a novel wavelength-division-multiplexing (WDM) source employing an uncooled and unisolated Fabry-Perot semiconductor laser diode (F-P SLD). The output wavelength of F-P SLD is locked to the externally injected narrow-band amplified spontaneous emission (ASE). The measured side-mode suppression ratio of the wavelength-locked F-P SLD is larger than 29 dB, when the extinction ratio of the directly modulated light output is above 13 dB. We achieved error-free transmission of 155-Mb/s data over 120 km of nondispersion-shifted fiber. We also propose a cost-effective WDM passive optical network architecture based on the proposed light sources.

Improved transmission of chirped signals from semiconductor optical devices by pulse reshaping using a fiber Bragg grating filter

Spectral filtering of chirped signals with an edge of a fiber grating filter improves propagation in nondispersion-shifted fiber. The improvement is due to a temporal shift of the frequency modulation with respect to the amplitude modulation. By filtering the chirped output of a semiconductor optical amplifier (SOA) wavelength converter with a fiber grating edge we obtain error-free transmission of converted data through 100 km of nondispersion-shifted fiber at 5 Gb/s.

40 Gbit/s 1.55 µm RZ transmission over 109km of non-dispersionshifted fibre with long continuously chirped fibre gratings

Chirped fibre gratings are compact and potentially cheap and have become an attractive alternative to technologies such as dispersion compensating fibres for the upgrade of the installed non-dispersion shifted fibre (NDSF) base. In particular the recent demonstrations of 10 Gbit/s transmission over 700 km of NDSF and 40 cm broadband (4 nm) linearly chirped gratings for much-increased source wavelength and operating condition tolerance confirm this potential. These long gratings have essentially flat reflectivity over their usable bandwidth with raised cosine apodisation at both ends of the spectrum. The delay characteristic can be controlled to be linear with less than 2% error with a dispersion slope as high as ~1700 ps/nm (enough for 100 km of standard fibre). At the same time, the broad bandwidth available from the long linearly chirped gratings makes it possible for the first time to achieve dispersion compensation over a significant length of NDSF at several tens of Gbit/s data rates. To date 40 Gbit/s transmission over a significant length of NDSF at 1.55µm has only been demonstrated using dispersion compensating fibres. The best result to our knowledge is an error-free transmission over 150 km of standard fibre. Without any means of dispersion management, the maximum transmission distance is ~4 km for this bit-rate. In this paper we report the first demonstration of 40 Gbit/s transmission over 109 km of NDSF at 1.55µm by employing two continuously-chirped 40 cm long, 4 nm-bandwidth gratings. In addition, a continuously-chirped 5.2 nm bandwidth 1 metre grating is demonstrated

Transmission of eight 20-Gb/s channels over 232 km of conventional single-mode fiber

As a demonstration of the upgradeability of conventional single-mode fiber systems, we demonstrate the transmission of eight 20-Gb/s channels over 232 km of nondispersion-shifted fiber using dispersion-compensating fiber with negative dispersion-slope. All channels were received without discernible transmission penalties. Due to fiber nonlinearity, differences were observed in system performance depending on the arrangement of the fibers. >

Transmission of 622 Mbit/s spectrum-sliced WDM channelover 60 km of nondispersion-shifted fibre at 1550 nm

The transmission of a spectrum-sliced WDM channel at 622 Mbit/s over 60 km of nondispersion-shifted fibre using an optical bandwidth of only 0.23 nm is reported. This is the highest single channel bit rate-length product (40 Gbit/s·km) and smallest channel bandwidth reported to date for spectrum-sliced WDM systems. The bit error rate performance is theoretically predicted and experimentally confirmed and limits on the bit rate-length products of spectrum-sliced WDM channels using nondispersion-shifted fibre in the 1550 nm window are given.