US 12,444,903 B2
Vertically integrated electro-absorption modulated lasers and methods of fabrication
Lawrence E. Tarof, Kanata (CA); Gudmundur A. Hjartarson, Ottawa (CA); and William A. Hagley, Ottawa (CA)
Assigned to ElectroPhotonic-IC Inc.
Filed by ElectroPhotonic-IC Inc., Kanata (CA)
Filed on Dec. 17, 2024, as Appl. No. 18/984,180.
Application 18/984,180 is a continuation of application No. 17/687,803, filed on Mar. 7, 2022, granted, now 12,272,925.
Application 17/687,803 is a continuation in part of application No. PCT/CA2020/051562, filed on Nov. 17, 2020.
Claims priority of provisional application 62/936,629, filed on Nov. 18, 2019.
Prior Publication US 2025/0233387 A1, Jul. 17, 2025
This patent is subject to a terminal disclaimer.
Int. Cl. H01S 5/026 (2006.01); G02B 6/122 (2006.01); H01S 5/00 (2006.01); H01S 5/02 (2006.01); H01S 5/10 (2021.01); H01S 5/12 (2021.01); H01S 5/22 (2006.01); H01S 5/323 (2006.01)
CPC H01S 5/0265 (2013.01) [G02B 6/1228 (2013.01); H01S 5/0014 (2013.01); H01S 5/0208 (2013.01); H01S 5/1014 (2013.01); H01S 5/1231 (2013.01); H01S 5/22 (2013.01); H01S 5/32391 (2013.01); H01S 5/026 (2013.01); H01S 5/12 (2013.01)] 20 Claims
OG exemplary drawing
 
8. A monolithically integrated electro-absorption modulated laser (EML) comprising:
a semi-insulating (SD) substrate;
an epitaxial layer stack formed on the SI substrate;
the epitaxial layer stack defining a plurality of vertically stacked waveguides, wherein the epitaxial layer stack comprises;
a first plurality of semiconductor layers formed on the SI substrate, the first plurality of semiconductor layers providing a first optical waveguide comprising an output waveguide;
a second plurality of semiconductor layers disposed above the first plurality of semiconductor lavers, the second plurality of semiconductor layers providing a second optical waveguide comprising an electro-absorption modulator (EAM) waveguide;
a third plurality of semiconductor layers disposed above the second plurality of semiconductor lavers, the third plurality of semiconductor layers providing a third optical waveguide comprising a laser waveguide;
the third optical waveguide is structured to define a distributed feedback (DFB) laser comprising a laser cavity and a first laterally tapered vertical optical coupler extending from an optical output of the laser cavity;
the second optical waveguide is structured to define a mesa of the EAM and a second laterally tapered vertical optical coupler extending from an optical output of the EAM;
the laser cavity is spaced from the EAM along a direction of optical propagation, the first laterally tapered vertical optical coupler being structured to couple an emitted optical mode from the laser an input of the EAM; and
the second laterally tapered vertical optical coupler is structured to vertically couple a modulated output from the EAM to the output waveguide; and
the DFB laser having first electrical contacts for operating the DFB laser in CW mode; and
the EAM having second electrical contacts for driving the BAM, and wherein,
the epitaxial layer stack comprises an other plurality of semiconductor layers comprising heterojunction bipolar transistors (HBTs) of electronic circuitry underlying the plurality of vertically stacked optical waveguides, said other plurality semiconductor layers of the electronic circuitry being vertically separated from the plurality of vertically stacked optical waveguides by at least one spacer layer;
the electronic circuitry comprising a laser driver and EAM driver and control circuitry; and
interconnect metallization providing electrically conductive interconnect tracks between the laser driver and the first electrical contacts of the laser and between EAM driver and control circuitry and the second electrical contacts of the EAM.