1.3 ?m bidirectional optical transmission over 31 km of installed single-mode fibre using optical couplers

Results are reported of 1.3 ?m bidirectional optical transmission over 31 km of installed cabled fibre at transmission rates of 34?650 Mbit/s using fused biconical tapered couplers manufactured at BTRL. With the introduction of 6 dB extra path loss it is possible to double the system capacity incurring only a small additional penalty at 34 and 140 Mbit/s and no other penalty at 320 and 650 Mbit/s.     

Transmission experiments through 101 km and 84 km of single-mode fibre at 274 Mbit/s and 420 Mbit/s

Four transmission experiments through low-loss single-mode optical fibre at 1.3 ?m have been performed at 274 Mbit/s and 420 Mbit/s with different objectives. The first demonstrates transmission through 101 km of single-mode fibre at 274 Mbit/s with negligible dispersion penalty. The second experiment at 274 Mbit/s and 84 km uses only components suitable for use in an undersea cable system. Two additional experiments, both at 420 Mbit/s, accomplish a bitrate × distance product of 35 GHzkm with 84 km of fibre and show no dispersion penalty with 63 km and 2.4 ps/km nm dispersion.     

Transmission experiments at 560 Mbit/s and 140 Mbit/s using single-mode fibre and 1300 nm LEDs

Transmission at 560 Mbit/s has been demonstrated using single-mode fibre and LEDs at 1300 nm. Surface-emitting, edge-emitting and super-radiant LEDs were used to transmit over maximum distances of 4.5 km, 15 km and 25 km, respectively. At 140 Mbit/s, the corresponding distances achieved with the same set of LEDs are 7.5, 35 and 50 km. respectively.     

400 Mbit/s optical heterodyne DPSK system experiment with inline1.5 μm amplifiers

Reports a 400 Mbit/s differential phase shift keying (DPSK) heterodyne optical transmission system experiment using two inline packaged resonant type amplifiers. The optical amplifier gave a 14.5 dB net gain from fibre to fibre at λ=1.488 μm with no significant system penalty     

102 km optical fibre transmission experiments at 1.52 ?m using an external cavity controlled laser transmitter module

The operation of a 1.52 ?m external cavity controlled laser transmitter module over 102 km of monomode fibre at 140 Mbit/s is reported. The laser emission is restricted to a single longitudinal mode by the external cavity, resulting in a system penalty of less than 0.5 dB.     

Wavelength-tunable 16 optical channel transmission experiment at 2Gbit/s and 600 Mbit/s for broadband subscriber distribution

Reports a 16 optical-channel single-mode fibre transmission experiment based on dense-WDM and tunable-etalon channel selection. Experiments at 2 Gbit/s and 600 Mbit/s over 10 km of single-mode fibre show little crosstalk penalty when the optical channel spacing is 2 nm. The system architecture is useful for high-capacity broadband subscriber distribution     

Feasibility of a 1 Gbit/s/ 565 Mbit/s bidirectional single-mode-fibre subscriber line for B-ISDN using 1279 nm/ 1315 nm wavelength division multiplexing

A laboratory system, transmitting 1 Gbit/s signals to a subscriber station and 565 Mbit/s signals back to a head station via one 20 km-long single-mode fibre, has been realised. Wavelength division multiplexing via two 3 dB fibre couplers of selectivity ?0.04 dB/nm has been used. The experiment demonstrates that bidirectional single-mode-fibre transmission is applicable to a future B-ISDN subscriber network.     

Novel high-speed LED transmitter for single-mode fibre and wideband loop transmission systems

A new high-speed LED transmitter using novel GaAs MESFET bias and drive circuits has been developed. It can modulate LEDs beyond 560Mbit/s with up to 200 mA drive current. At 560Mbit/s, extinction ratios of 15 dB were attained with devices that otherwise operated up to 250Mbit/s. The transmitter was designed for single-mode loop applications.     

Performance of erbium-doped fibre amplifier in 16-channel coherent broadcast network

The performance of an erbium-doped fibre amplifier in a 16-channel coherent broadcast network operating at 155 Mbit/s has been experimentally investigated. A fibre-to-fibre gain of 22 dB at 1540 nm allowed simulation of a network that serves 256 end-users over a distance of 102 km.<>     

Chromatic dispersion penalty by angular coupling between resonant cavity light-emitting diode and plastic optical fibre

Chromatic dispersion penalty by angular coupling between a resonant cavity light-emitting diode (RCLED) and a plastic optical fibre is presented. To evaluate the influence of the angular-dependent spectral characteristics of the RCLED on the chromatic dispersion penalty, the effective spectral linewidth of the RCLED was defined and the bit error rate performances for 500 Mbit/s by 50 m transmission were calculated. The calculated results were in good agreement with the experimental ones that showed the chromatic dispersion penalty of 1.2 dB at BER = 10 ^-12 in the angle of 26°.     

Fibre transmission of 10 Gbit/s signals following wavelengthconversion using a travelling-wave semiconductor optical amplifier

The wavelength of an intensity-modulated signal at 10 Gbit/s was translated from 1546 to 1531 nm using cross gain-compression in a semiconductor optical amplifier. The shifted signal was transmitted with less than 1 dB penalty over a 121 km span of dispersion-shifted fibre with two in-line amplifiers. A dispersion penalty of nearly 2 dB is measured for transmission of 6 Gbit/s data over 20 km conventional fibre     

Long span coherent transmission with erbium ytterbium doped fibre power amplifier over a 70 dB loss budget

A combination of a high power Er/Yb fibre optic amplifier and a coherent transmission system are used to achieve very large optical link loss budgets of 70 dB at 167 Mbit/s and 67 dB at 622 Mbit/s. A transmit power of +18.2 dBm was launched into low loss optical fibre without evidence of stimulated Brillouin scattering.<>     

First plastic optical fibre transmission experiment using 520 nmLEDs with intensity modulation/direct detection

A plastic optical fibre (POF) transmission experiment utilising green LEDs at a wavelength of 520 nm is reported. The transmission loss of the 100 m POF was 10 dB, which is considerably lower than the loss for red (660 nm) and blue (470 nm) LEDs. The receiver sensitivity at 30 Mbit/s was -20.8 dB at 10^-9 bit error rate, which suggests the possibility of a longer length signal transmission, 200 m or longer     

Two-channel system demonstration of differential frequency-deviation multiplexing

A two-channel lightwave system using differential frequencydeviation multiplexing (DFDM) is presented. Both 90Mbit/s channels are differentially detected using a fibre interferometer. The performance is independent of the absolute optical frequencies and received state of polarisation. Interchannel interference results in a 1 dB penalty for channel separations of 700 MHz.     

Penalty-free 10 Gbit/s single-channel co-pumped distributed Ramanamplification using low RIN 14xx nm DFB pump

A penalty-free 10 Gbit/s single-channel transmission with co-pumped distributed Raman amplification using a novel high power, low relative integrity noise (RIN), multimode 14xx nm distributed feedback pump is reported. No penalty from pump to signal RIN transfer was observed with co-pumped Raman gains up to 6 dB large effective area fibre (LEAF). In contrast, 0.5 dB penalty was observed with a fibre Bragg grating stabilised pump at 6 dB of Raman gain     

560 Mbit/s transmission experiment using 1.3 ?m InGaAsP/InP LED

Using a high-speed InGaAsP/InP LED, 560 Mbit/s signal transmission over 4.4 km has been realised with a large-bandwidth graded-index fibre at 1.3 ?m wavelength and a bit-error rate of 10?9.     

Flatly broadened supercontinuum generation at 10 Gbit/s using dispersionflattened photonic crystal fibre with small normal dispersion

Supercontinuum generation at 10 Gbit/s using a nonlinear dispersion-flattened photonic crystal fibre is experimentally demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 ps nm^-1 km^-1 between 1500 and 1650 nm. The supercontinuum with a flatly broadened spectrum of 92 nm (at 6 dB) in the 1.55 mum region is generated by injecting 1545 nm, 1.5 ps optical pulses into an 80 m-long fibre     

2.5 Gbit/s transmission of spectrum-sliced fibre amplifier lightsource channels over 200 km of dispersion-shifted fibre

Transmission of 2.5 Gbit/s spectrum-sliced fibre amplifier light source channels over 200 km of dispersion-shifted fibre (DSF) has been achieved, the highest bit-rate distance product 500 Gbit/s km using incoherent light sources reported to our knowledge. The total power penalty was as low as 0.2 dB for the 1.8 nm bandwidth channel centred at the zero-dispersion wavelength of DSF     

Optical transmission over 140 km at 40 Gbit/s by optical timedivision multiplexing/demultiplexing

Transmission at 40 Gbit/s over 140 km of dispersion-shifted fibre has been demonstrated. An optical sensitivity of 28.5 dBm (BER=10⁹ ) was achieved at the optimum operating wavelength of 1556 nm and a power penalty of <1 dB was obtained for 1554-1557.5 nm wavelengths. The two optically demultiplexed 20 Gbit/s channels exhibited negligible difference in sensitivity     

Transmission at 1 Gbit/s over 7.4 km of single-mode fibre using an edge-emitting LED and PINFET receiver

Transmission at 1 Gbit/s over 7.4 km of 1300 nm optimised single-mode fibre has been demonstrated using a standard, 1300 nm edge-emitting LED with 150 MHz 3 dB bandwidth and a PINFET receiver. Computer simulation was used to accurately assess each of the system degradations: LED rise/fall, extinction ratio, dispersion penalty and receiver noise.