Robert F Tavlykaev

6795620, Sep 21, 2004

Nov 27, 2002

10/304699

Robert Tavlykaev - Ellicott City MD
Alan Donaldson - Clarksville MD

Codeon Corporation - Columbia MD

G02B 642

385 48

A method and optical tap is provided for forming a monitor signal that is a measure of optical power in a guided mode output of an optical modulator. The method and optical tap may monitor the guided mode power without tapping the guided mode light, even when optical power of the radiation modes is non-complementary to that of the output mode. Light from the radiation modes of the optical modulator is coupled into the wall of a capillary through a front face. Separate portions of the radiation mode light are reflected into photodetectors, which form photocurrents that are incoherently added to form the monitor signal.

6978056, Dec 20, 2005

Jun 4, 2003

10/454077

Robert Tavlykaev - Ellicott City MD, US

Covega, Inc. - Jessup MD

G02F001/035

385 2, 385 1, 385 14, 385 40, 385 41, 385129, 385130, 385132, 385 8, 385 9

Optical modulators with reduced temperature dependence on bias control are described. A set of bias electrodes is arranged relative to a set of RF electrodes in a manner which results in the opening point of the device remaining relatively constant as a function of temperature. The arrangement of the bias electrodes relative to the RF electrodes includes a physical offset of one set of electrodes relative to the other, with or without a reversal of polarity of one set of electrodes relative to the other. Arrangements according to the present invention create a symmetrical electrode arrangement from a temperature-induced stress point of view so that the operating point of the device remains relatively constant as a function of temperature.

7027668, Apr 11, 2006

May 2, 2003

10/427982

Robert F. Tavlykaev - Ellicott City MD, US
Ganesh K. Gopalakrishnan - Bethesda MD, US
Scott T. Taylor - Woodstock MD, US

Covega Corporation - Jessup MD

G02B 6/26
G02B 6/10
G02F 1/035
G02F 1/295

385 2, 385 8, 385 41, 385129, 359246, 359254, 359322

The present invention relates to an optical modulator including an optical waveguide, and at least one CPW-to-CPS transition. The CPW segments include a hot electrode; and a ground plane disposed on each side of the hot electrode, and they share a ground plane. The CPS segment extends along an interaction length of the modulator. In one embodiment, two driving signals are applied so that the modulator operates as a dual-drive modulator. In another embodiment, a domain-inverted region is formed in a substrate of the dual-drive modulator to overlap with one arm of the optical waveguide (MZI) and invert a sign of a phase shift induced in that arm. Finally, a fixed chirp can be introduced into the dual-drive modulator by asymmetrically positioning the interferometer arms into gaps of the CPW segments with respect to the hot electrode, and by employing unequal width gaps in the CPW segments.

59179740, Jun 29, 1999

Aug 1, 1997

8/904895

Robert F. Tavlykaev - Gainesville FL
Ramu V. Ramaswamy - Gainesville FL

Advanced Photonics Technology, Inc. - Gainesville FL

G02B 626

385 50

The subject invention pertains to a method of apodizing interaction in spatially-coupled waveguides capable of implementing any desired interaction-strength profiles, for example, alternating functions. Wavelength filters with various types of spectral response can be synthesized. In a preferred embodiment, a Butterworth-type interaction profile is disclosed which provides a flat-top response with suppressed sidelobes. The method according to the subject invention is based on spatially offsetting a single-mode waveguide with respect to a two-mode waveguide in which the anti-symmetric mode is excited by using a Y-junction mode splitter. The method can easily be implemented in vertically-coupled structures fabricated with the use of conventional fabrication processes. Various embodiments of the method implemented. The subject invention further pertains to the device produced in accordance with the methods of the subject invention.

61012963, Aug 8, 2000

Jul 31, 1998

9/127092

Robert F. Tavlykaev - Gainesville FL
Ramu V. Ramaswamy - Gainesville FL

Advanced Photonics Technology, Inc. - Gainesville FL

G02B 1035

385 2

The subject invention pertains to electro-optic devices and, in particular, to an integrated-optic modulator with a linearized transfer curve. In a specific embodiment, an integrated-optic modulator with a linearized transfer curve can be formed in an electro-optic substrate and comprises an input Y-junction, a section of two coupled waveguides, followed by two output waveguide bends. Light from a CW optical source can be launched into the input Y-junction and amplitude modulated by applying an external voltage to the electrodes positioned on the top surface of the substrate. The modulator can be driven in both the uniform and. DELTA. beta. configuration. By properly adjusting the length of the sections in the coupler with respect to the coupling length, the linearity of the transfer curve is improved The subject invention is further concerned with realizing modulators with suppressed nonlinear distortions for analog optical links, for example fiber-optic communication links and cable television systems. Third-order harmonics and intermodulation distortions of the Y-fed modulator can be significantly suppressed, thus, increasing the dynamic range of an analog optical system that incorporates the modulator. A two-section linearized Y-fed modulator with a domain reversal in a ferroelectric material is described which utilizes a simple uniform electrode structure fully compatible with high-speed applications.

62367722, May 22, 2001

May 2, 2000

9/561637

Robert F. Tavlykaev - Gainesville FL
Ramu V. Ramaswamy - Gainesville FL

Advanced Photonics Technology, Inc. - Gainesville FL

G02F 1035

385 2

The subject invention pertains to electro-optic devices and, in particular, to an integrated-optic modulator with a linearized transfer curve. In a specific embodiment, an integrated-optic modulator with a linearized transfer curve can be formed in an electro-optic substrate and comprises an input Y-junction, a section of two coupled waveguides, followed by two output waveguide bends. Light from a CW optical source can be launched into the input Y-junction and amplitude modulated by applying an external voltage to the electrodes positioned on the top surface of the substrate. The modulator can be driven in both the uniform and Db configuration. By properly adjusting the length of the sections in the coupler with respect to the coupling length, the linearity of the transfer curve is improved. The subject invention is further concerned with realizing modulators with suppressed nonlinear distortions for analog optical links, for example fiber-optic communication links and cable television systems. Third-order harmonics and intermodulation distortions of the Y-fed modulator can be significantly suppressed, thus, increasing the dynamic range of an analog optical system that incorporates the modulator.