Basil W Hakki

6549311, Apr 15, 2003

Jul 14, 1999

09/353716

Basil Wahid Hakki - Allentown PA
Robert W. Smith - Allentown PA

Lucent Technologies Inc. - Murray Hill NJ

H04B 1004

359124, 359109, 359183

A wave division multiplexing system in which low frequency intensity modulation of the optical channels is avoided in order to reduce or substantially prevent inter-channel cross-talk of low frequency telemetry signals by phase modulating the low frequency telemetry signal so as to recover the transmitted signal at the receiver. The system includes multiple transmitters and receivers. Each transmitter includes an optical source, such as a laser, a radio frequency generator having a low frequency telemetry signal impressed thereon, and an optical phase modulator. The phase modulated low frequency telemetry signal generated by each transmitter is combined using a multiplexer before being amplified and transmitted through a single optical fiber. A demultiplexer receives the transmitted signal and separates it into respective optical channels based on the particular frequency of each transmitter. Respective signals for each optical channel are transmitted to an associated receiver.

6631003, Oct 7, 2003

Nov 9, 1999

09/436766

Basil W. Hakki - Allentown PA

Lucent Technologies Inc. - Murray Hill NJ

G01B 902

356477, 356450

An uncorrelated Michelson interferometer is formed with single mode optical fiber. In a first embodiment, light is transmitted into an optical 3 dB coupler, and split into a transmission down a first optical fiber and transmission down a second, significantly longer second optical fiber. In the disclosed embodiment, the second optical fiber path may be several meters, and even hundreds of meters longer than that of the first fiber optic path. The light at the ends of the respective first and second fiber optic paths is reflected back into the single mode optical fiber, and coupled in the optical coupler. In the first embodiment, since the second fiber optic is relatively long, an unknown amount of rotation of the polarization would otherwise occur. Thus, a polarization controller is used to control the polarization in the longer, second optical fiber such that a maximum signal is output from the optical coupler. The interference between the reflected and coupled light signals from the two fiber optic paths is uncorrelated if the difference in path lengths 2L (up and back in each fiber optic path) exceeds the optical coherence length of the signal in the single mode optical fiber.

60883731, Jul 11, 2000

Feb 17, 1999

9/251629

Basil Wahid Hakki - Allentown PA

Lucent Technologies Inc. - Murray Hill NJ

H01S 310
H01S 330
H01S 313
H01S 308
G02B 626

372 20

A hybrid tunable Bragg laser including a double heterostructure gain section, a Bragg reflector section optically coupled to said gain section, and an optical extension constructed to yield a plurality of longitudinal modes. Preferably, the optical section has a predetermined length and effective reflectivity adapted to yield the plurality of longitudinal modes.

62817655, Aug 28, 2001

Mar 9, 1999

9/265559

Basil Wahid Hakki - Allentown PA
Ton Van Nguyen - Breinigsville PA

Agere Systems Optoelectronics Guardian Corp. - Orlando FL

H03H 730
H01D 900

333156

A non-mechanical electrically adjustable delay device which does not suffer from interruptions in impedance inherent in multiple-tap delay lines. The wide band electrical delay line is capable of delaying a wide band of signals without significant distortion, e. g. , up into the microwave range, and allows continuous transmission of a signal between the input port and the output port. The exemplary wide band electrical delay line comprises two transmission lines, preferably parallel to one another, and having different propagation velocities. A plurality of electrical cross connect circuits are connected between the two transmission lines. The electrical cross connect circuits are spaced along the lengths of the two transmission lines, e. g. , preferably to form evenly spaced distances therebetween. The total delay through the wide band electrical delay line is adjusted by selectively activating an appropriate one of the plurality of cross connect circuits between the two transmission lines.

60112530, Jan 4, 2000

Mar 31, 1998

9/052756

Basil W. Hakki - Allentown PA

Lucent Technologies Inc. - Murray Hill NJ

G02F 101

250225

Methods for analyzing polarization mode dispersion of an optical device is provided. Various desired qualities of the device, including position dependent optical and physical qualities, can be determined. Experimental wavelength-dependent PMD data are provided that characterizes the entire optical device. The experimental data are Fourier transformed and an experimental Fourier transform is constructed. A theoretical Fourier transform is calculated and fit to the experimental transform by varying at least one parameter. Based on the fit parameters, one or more qualities, including a PMD profile of the device, can be determined. An apparatus for use with this method is also provided.

56594127, Aug 19, 1997

Dec 6, 1994

8/350287

Basil Wahid Hakki - Allentown PA

Lucent Technologies Inc. - Murray Hill NJ

H04B 1000
H04B 1006

359156

An apparatus and method which utilize polarization diversity detection to compensate for polarization-mode dispersion (PMD) introduced in an optical signal propagating over a medium such as optical fiber. A received optical signal is separated into first and second polarization components by a polarization beam splitter (PBS). A control signal corresponding to a phase difference between the polarization components is used to drive at least one polarization controller located in the optical signal path before the PBS, such that the two polarization components are aligned with the PSPs of the received optical signal. The control signal may also be used to adjust a variable delay element such that phases of the two polarization components are aligned before the components are combined to provide a PMD-compensated output signal. Other aspects of the invention are directed to polarization control using a rotator element with low numerical aperture input and output signal coupling, and to the use of feedback control to compensate for variations in loss through a polarization controller.