Techniques for magnetic shielding of an optical isolator to maintain nominal magnetic flux density and a transmitter or transceiver system implementing same

A multi-channel optical transceiver comprising:

• a substrate;
• a transmitter optical subassembly (TOSA) module coupled to the substrate, the TOSA module comprising:
• a TOSA housing defining a cavity;
• an optical coupling receptacle and a coupler section to couple the optical coupling receptacle to the TOSA housing;
• a laser diode disposed in the cavity to emit an associated channel wavelength;
• an optical isolator, the optical isolator optically coupled to the laser diode and having an associated magnetic field to determine a direction of propagation for the associated channel wavelengths;
• and
• a magnetic shield at least partially surrounding the optical isolator, the magnetic shield to reflect the associated magnetic field away from components of the TOSA module to maintain a magnetic flux density of the associated magnetic field, wherein the magnetic shield comprises a cylindrical body disposed in a cavity defined by the coupler section;
• a receiver optical subassembly (ROSA) coupled to the substrate.