Anatoli A. Abramov

A gain-flattened ultra wide band EDFA for high capacity WDM optical communications systems

An 84 nm gain-flattened ultra wide band erbium-doped silica fiber amplifier for high capacity WDM optical communication systems is demonstrated with a noise figure of 6 dB and an output power of 25 dBm. We demonstrated an ultra wide band EDFA with a two-section, split band structure. The total 3dB bandwidth is 84.3 nm, which should be able to support 100 WDM channels with 100 GHz channel spacing or 200 WDM channels with 50 GHz channel spacing. The split bands allow independent optimization of each band for dispersion compensation and span loss variations.

Dense wavelength-division multiplexed transmission in "zero-dispersion" DSF by means of hybrid Raman/erbium-doped fiber amplifiers

Transmission of 25 and 50 equally 100-GHz and 50-GHz spaced 10-Gb/s (OC-192) channels on the ITU grids is demonstrated over eight and four 83.8-km long spans, respectively, of DSF with the zero-dispersion wavelength within the signal wavelength band. Significant performance improvements are obtained with a pump power of only 440 mW with 55-/spl mu/m/sup 2/ dispersion-shifted fibers because of their relatively high Raman efficiency.

8 x 10 Gb/s 1.3-μm unrepeatered transmission over a distance of 141 km with Raman post- and pre-amplifiers

A repeaterless wavelength-division-multiplexed transmission system operating in the 1.3-/spl mu/m wavelength window is demonstrated by means of discrete Raman fiber amplifiers. The power budget is 45.1 dB, leaving a margin of 1.6 dB for a transmission distance of 141 km. The eight channels, which occupy a wavelength range from 1305.8 to 1311.6 nm, carry data at a rate of 10 Gb/s each. The Raman post- and pre-amplifier both employ a two-stage ring topology, which allows counterpropagating pumping.

Temperature-sensitive long-period fiber gratings for wideband tunable filters

We present a new type of long-period fiber gratings with enhanced temperature sensitivity of 80 nm/100/spl deg/C via the use of specially designed polymer. New structures are presented, which should enable tunable filters for communications systems.

L-band 64/spl times/10 Gb/s DWDM transmission over 500 km DSF with 50 GHz channel spacing

We demonstrate error-free transmission of 64 DWDM 10 Gb/s channels in the L-band with 50 GHz channel spacing over 5/spl times/100 km spans of dispersion-shifted fiber.

Electrically tunable efficient broadband long-period fiber grating filter

Summary form only given. We present a new type of the tunable optical fibre filter based on a metal coated long period grating (LPG) written in a specially-developed fiber containing air regions inside the cladding. The air regions are filled with polymers with high temperature sensitivity resulting in broadband tuning range and high electrical heating efficiency. These new structures are attractive because they are practically insensitive to the variations of the refractive index of the surroundings, and thus can be coated by metal with no measurable changes in the transmission spectrum.

10-Gbit/s repeaterless transmission at 1.3 /spl mu/m with 55.1-dB power budget using Raman post- and preamplifier

Summary form only given. Here we show that the performance of 1.3-/spl mu/m Raman amplifiers can match the best results obtained with erbium-doped fiber amplifiers (EDFAs) and demonstrate l0-Gbit/s unrepeated transmission at 1.3 /spl mu/m over 168.5 km of standard single-mode fiber with a record power budget of 55.1 dB. The 55.1-dB power budget is achieved using a Raman booster amplifier at the transmitter and a Raman preamplifier at the receiver.