US 12,306,511 B2
Optical signal transmitter including folded coupling configuration of laser source to microwave photonic integrated circuit
Henry Hung, Paradise Valley, AZ (US); Leijun Yin, Tempe, AZ (US); Ke Huang, Phoenix, AZ (US); and Xiaoyan Ying, Tempe, AZ (US)
Assigned to Optilab, Inc., Phoenix, AZ (US)
Filed by OPTILAB, LLC, Phoenix, AZ (US)
Filed on May 26, 2022, as Appl. No. 17/826,023.
Claims priority of provisional application 63/212,432, filed on Jun. 18, 2021.
Prior Publication US 2022/0404679 A1, Dec. 22, 2022
Int. Cl. G02F 1/225 (2006.01); G02F 1/21 (2006.01)
CPC G02F 1/212 (2021.01) [G02F 1/2255 (2013.01); G02F 2202/20 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a Mach-Zehnder interferometer (MZI) modulator, comprising:
a Y-optical splitter;
a first thin-film lithium niobate (TFLN) waveguide formed within a TFLN material layer, wherein the first TFLN waveguide has a first index of refraction greater than a second index of refraction of the TFLN material layer, and wherein the first TFLN waveguide is coupled to a first output of the Y-optical splitter;
a second TFLN waveguide formed within the TFLN material layer, wherein the second TFLN waveguide has the first index of refraction, and wherein the second TFLN waveguide is coupled to a second output of the Y-optical splitter;
a Y-optical combiner including a first input coupled to the first TFLN waveguide and a second input coupled to the second TFLN waveguide; and
first and second electrical conductors situated proximate the first and second TFLN waveguides, wherein the first and second electrical conductors are configured to receive a direct current (DC) bias voltage across the first and second electrical conductors;
a laser source coupled to an input of the Y-optical splitter of the MZI modulator;
a submount over which the MZI modulator is mounted;
a collimating lens optically coupled to the laser source, wherein the collimating lens is positioned in a groove formed in the submount for optically aligning with the laser source; and
an optical isolator optically coupled to the collimating lens, wherein the optical isolator is also positioned within the groove of the submount for optically aligning with the collimating lens and the laser source.