Fiber stub for cladding mode coupling reduction

An optical device comprising:

• a laser;
• a fiber stub comprising:
• a ferrule including a glass material;
• and
• a glass fiber positioned within the ferrule, the glass material of the ferrule having a refractive index that is greater than the refractive index of at least a portion of the glass fiber;
• and
• a lens that couples light transmitted emitted by the laser into the fiber stub.

An optical transceiver comprising:

• a receiver optical subassembly;
• and
• a transmitter optical subassembly comprising:
• a laser;
• and
• a single-mode fiber stub including:
• a ferrule comprising a glass material;
• and
• a glass fiber positioned within the ferrule, the glass fiber including a cladding and a core, the glass material of the ferrule has a refractive index that is greater than the refractive index of the glass fiber;
• and
• a lens that couples light emitted by the laser into the fiber stub.