A silicon-based edge coupler for coupling a fiber with a waveguide includes a cantilever member being partially suspended with its anchored end coupled to a silicon photonics die in a first part of a silicon substrate and a free end terminated near an edge region separating a second part of the silicon substrate from the first part. The edge coupler further includes a mechanical stopper formed at the edge region with a gap distance ahead of the free end of the cantilever member. Additionally, a V-groove is formed in the second part of the silicon substrate characterized by a top opening and a bottom plane symmetrically connected by two sloped side walls along a fixed Si-crystallography angle. The V-groove is configured to support a fiber with an end facet being pushed against the mechanical stopper and a core center being aligned with the free end of the cantilever member.