The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 1990
Filed:
Nov. 14, 1988
Per O Granestrand, Tyreso, SE;
Telefonaktiebolaget L M Ericsson, Stockholm, SE;
Abstract
Polarization directing optoelectronic coupler on a wafer of doubly refracting material with an optical axis (L1). The coupler has an interaction region (L1) with waveguides (L1) and an electrode means. The interaction region (L1) is divided into two sections with a central electrode and two outer electrodes in each section. Voltage sources are connected to the electrodes and generate electrical fields through the waveguides. The electrical field between the outer electrodes has in each section the same direction in both waveguides and achieves an .DELTA.H modulation. The electrical field between the central electrode and outer electrodes has mutually reverse direction in both waveguides in the sections and achieves a .DELTA..beta. modulation. For an arbitrarily polarized lightwave both the crossover state and the bar state can be achieved for both the TE and TM modes or one of its oscillation modes can be crossed over and the other of its oscillation modes can be coupled straight through. The directional coupler can be driven at low voltages and the required manufacturing accuracy is relatively low.