Optical module and a fabrication process thereof

A method for manufacturing an optical module that includes:

• a first substrate carrying one or more grooves on an upper major surface thereof at respective, predetermined positions, said one or more grooves extending substantially parallel with each other for carrying one or more optical fibers therein;
• and a second substrate carrying one or more optical devices on an upper major surface thereof in correspondence to said one or more optical fibers;
• said second substrate having at least a pair of polygonal projections at respective predetermined positions corresponding to grooves on said upper major surface of said first substrate;
• said second substrate being mounted upon said first substrate such that an end surface of said first substrate faces said upper major surface of said second substrate and such that said polygonal projections on said upper major surface of said second substrate engage with corresponding grooves on said upper major surface of said first substrate, at said end surface of said first substrate;
• said method comprising the steps of:
• forming said polygonal projections by applying an anisotropic etching process to said device substrate;
• and
• forming an optical device on at least one of said polygonal projections monolithically.