Ferrule assembly and optical module

An optical module comprising:

• a substrate having a first marker;
• an optical waveguide layer formed on said substrate, said optical waveguide layer including an optical waveguide core having a plurality of first ends, and an optical waveguide cladding covering said optical waveguide core and having a narrow first portion;
• a connector assembly including a block having a plurality of through holes, a plurality of optical fibers inserted and fixed in said through holes, respectively, and a plurality of guide pins fixed to said block, said block having a flat cut portion for semicylindrically exposing a part of each of said optical fibers inserted and fixed in said through holes;
• and
• a glass plate having a second marker, a plurality of first grooves for receiving said parts of said optical fibers exposed to said flat cut portion, and a second groove for receiving said first portion of said optical waveguide cladding;
• wherein said glass plate is fixed to said substrate so that said second marker of said glass plate is aligned with said first marker of said substrate, and that said second groove receives said first portion of said optical waveguide cladding;
• and
• said connector assembly is fixed at said flat cut portion to said glass plate so that said parts of said optical fibers exposed to said flat cut portion are received in said first grooves of said glass plate.