1
Brenda B Amarant, William H Desmedt, David C McChristian, Robert M Neilon: Monitoring of charges debited to an account having an assigned limit. AT&T, Eugene J Rosenthal, Eli Weiss, September 12, 1995: US05450477 (155 worldwide citation)

Charges and balances assignable to a credit card account are controlled and monitored by assigning a purchase limit to the card. More specifically, when a card is used to pay for a telephone call on a telecommunication network, the validity of the card is verified in, for example, a network database ...


2
David J DiGiovanni, Clinton R Giles: Multi-stage optical fiber amplifier. AT&T Bell Laboratories, Eli Weiss, September 24, 1991: US05050949 (122 worldwide citation)

In this invention there is disclosed a multi-stage optical fiber amplifier for providing a new functon, that of gain equalization. The disclosed multi-stage optical fiber amplifier comprises at least two stages of amplification where each stage comprises an amplifying fiber having a different gain s ...


3
Vincent W S Chan, Robert G Gallager, Alan J Kirby, Adel A M Saleh: All-optical network architecture. AT&T Bell Laboratories, Digital Equipment Corporation, Massachusetts Institute of Technology, Eli Weiss, Stuart H Mayer, September 27, 1994: US05351146 (115 worldwide citation)

There is disclosed the architecture for an all optic network which employs a three level hierarchy using wavelength vision multiplexing. At the lowest level of the hierarchy are Level-0 all optical networks. The Level-0 networks are "local" broadcast networks each of which supports a plurality of ac ...


4
David J DiGiovanni, Clinton R Giles: Multi-stage optical amplifier. AT&T Bell Laboratories, Eli Weiss, May 19, 1992: US05115338 (77 worldwide citation)

This invention relates to an Erbium-doped fiber amplifier having multiple stages of amplification for providing enhanced performance. More specifically, optical means is located intermediate first and second stages of doped optical amplifying fibers adapted to receive a pump signal at a pump wavelen ...


5
M Fatein Mahmoud: Multi-location video conference system. American Telephone and Telegraph, AT&T Bell Laboratories, Eli Weiss, November 21, 1989: US04882743 (70 worldwide citation)

The invention, which can be used with AT&T SKYNET.RTM. digital satellite communications service allows a conference director to control a teleconference between several conference rooms. In this invention there are two transmitting channels, one being identified as a broadcast channel and the other ...


6
Emmanuel Desurvire, Clinton R Giles, Jay R Simpson, John L Zyskind: Erbium-doped fiber amplifier. AT&T Bell Laboratories, Eli Weiss, April 2, 1991: US05005175 (64 worldwide citation)

This invention is a rare earth doped optical amplifier with increased gain and lowered pump thresholds. The amplifying scheme is based on a 3 level lasing system rather than the more prevalent 4 level lasing system. Additionally, the transmission mode of the optical fiber at the pump wavelength has ...


7
Emmanuel Desurvire, Clinton R Giles: Method of operating concatenated optical amplifiers. AT&T Bell Laboratories, Eli Weiss, May 26, 1992: US05117303 (57 worldwide citation)

In a transmission system having concatenated optical amplifiers, gain saturation of the optical amplifiers at any stage is caused by the extraction of power from the amplifier by the ASE and amplification of the signal and of the ASE from previous stages. Three methods of operating transmission syst ...


8
Emmanuel Desurvire, Clinton R Giles, John L Zyskind: Erbium-doped fiber amplifier. AT&T Bell Laboratories, Eli Weiss, June 25, 1991: US05027079 (51 worldwide citation)

This invention relates to an Erbium doped fiber amplifier having improved operating characteristics. Parameters which determine the operating characteristics of an erbium doped fiber amplifier are the concentration of erbium in the core of a fiber; the ratio of the radius of the core of the fiber do ...


9
Emmanuel Desurvire, Randy C Giles, Matthew S Whalen: Erbium-doped fiber amplifier coupling device. AT&T Bell Laboratories, Eli Weiss, October 16, 1990: US04963832 (49 worldwide citation)

This invention is directed toward reducing substantially the loss incurred when two optical fibers of different mode diameters are coupled together. In this invention, the coupling of one fiber to that of another where the fibers are of different mode diameters is not with a tapered fusion, core-to- ...


10
Andrew R Chraplyvy, Xiaoping Mao, Robert W Tkach: Suppression of brillouin scattering in lightwave transmission system. AT&T, Eli Weiss, May 30, 1995: US05420868 (49 worldwide citation)

Optical nonlinear effects, such as stimulated (Brillouin) scattering, cause disproportionate attenuation of transmitted optical signals and usually occurs only when the optical power exceeds a certain level. One of the most important types of nonlinear scattering which occurs in an optical fiber as ...