Optical waveguides – Temporal optical modulation within an optical waveguide – Electro-optic
Patent
1998-07-31
2000-08-08
Ullah, Akm E.
Optical waveguides
Temporal optical modulation within an optical waveguide
Electro-optic
G02B 1035
Patent
active
061012963
ABSTRACT:
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.
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Ramaswamy Ramu V.
Tavlykaev Robert F.
Advanced Photonics Technology, Inc.
Ullah Akm E.
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