Inventors:
Suwat Thaniyavarn - Bellevue WA
Assignee:
TRW Inc. - Redondo Beach CA
International Classification:
G01B 902
Abstract:
An improved electro-optic coupled waveguide interferometer (50) is provided. The device comprises a single input (52), a Y-junction splitter (54), two interferometric arms (56a, 56b), a Y-junction combiner (58), a single output (60) and multiple equal-length sections of electrodes (62a-d) with alternating applied voltage polarities. The device of the invention permits use of much smaller Y-junction branching angle, which reduces scattering losses, or a shorter branching waveguide section, which allows construction of a device having an overall shorter length than prior art interferometers. The device takes advantage of a close placement of the interferometer arms, which results in a transfer of optical energy and facilitates a single-gap electrode structure for efficient push-pull operation. The use of multiple-section electrodes restores the high modulation depth otherwise destroyed by the close placement of the interferometric arms.