US 12,481,198 B2
Providing drive signals for a differential drive modulator
Maxime Jacques, Montreal (CA); Gregory Brookes, Québec (CA); Michael Vitic, Chelsea (CA); and Jean-Frédéric Gagné, Québec (CA)
Assigned to Ciena Corporation, Hanover, MD (US)
Filed by Ciena Corporation, Hanover, MD (US)
Filed on May 24, 2023, as Appl. No. 18/323,018.
Application 18/323,018 is a continuation in part of application No. 17/352,538, filed on Jun. 21, 2021, granted, now 12,001,116.
Prior Publication US 2023/0305356 A1, Sep. 28, 2023
Int. Cl. G02F 1/225 (2006.01); G02F 1/035 (2006.01)
CPC G02F 1/2257 (2013.01) [G02F 1/0356 (2013.01); G02F 1/2255 (2013.01); G02F 2201/127 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An apparatus comprising:
an electro-optic material;
an optical waveguide structure forming a Mach-Zehnder interferometer in proximity to the electro-optic material, where the Mach-Zehnder interferometer includes a first optical waveguide arm and a second optical waveguide arm;
a first electrical input port configured to receive a first drive signal;
a second electrical input port configured to receive a second drive signal that has a negative amplitude relative to the first drive signal;
a first transmission line configured to propagate a first electromagnetic wave over at least a portion of the first optical waveguide arm to apply an optical phase modulation to an optical wave propagating in the first optical waveguide arm according to an electro-optic modulation of a portion of the electro-optic material;
a second transmission line configured to propagate a second electromagnetic wave over at least a portion of the second optical waveguide arm to apply an optical phase modulation to an optical wave propagating in the second optical waveguide arm according to an electro-optic modulation of a portion of the electro-optic material; and
a drive signal interconnection structure configured to provide a first electrical connection between the first electrical input port and an inner electrode shared by the first and second transmission lines, and a second electrical connection between the second electrical input port and respective outer electrodes of the first and second transmission lines, where the drive signal interconnection structure is configured to preserve relative phase shifts between the first and second drive signals;
where a first impedance associated with a first electric field distribution between the inner electrode and a first of the outer electrodes and a second impedance associated with a second electric field distribution between the inner electrode and a second of the outer electrodes are substantially equal to each other to provide impedance matching;
where the inner electrode and outer electrodes are disposed between a first ground electrode and a second ground electrode, with the first ground electrode and the second ground electrode being electrically grounded and associated with a third electric field distribution between a first of the outer electrodes and the first ground electrode and a fourth electric field distribution between a second of the outer electrodes and the second ground electrode, and
where the third electric field distribution and the fourth electric field distribution contribute to providing the impedance matching.