Optical waveguide package and light-emitting device

An optical waveguide package, comprising:

• a substrate including a first surface;
• a cladding on the first surface, the cladding including a second surface facing the first surface, a third surface opposite to the second surface, and an element mount with an opening in the third surface;
• and
• a core in the cladding,
• wherein the element mount is an area for mounting a light-emitting element,
• the cladding includes a first portion having the core extending in a first direction of the substrate, and a second portion around the element mount and in a different position from the first portion,
• the first portion includes a first protrusion, or a plurality of first protrusions, in a first area of the third surface corresponding to the first portion,
• the second portion includes a plurality of second protrusions in a second area of the third surface corresponding to the second portion, and
• the plurality of first protrusions is located above the core.