Redundant light supply for silicon photonic chip

A system, comprising:

• a first silicon photonic chip;
• a second silicon photonic chip to supply light to the first silicon photonic chip, the second silicon photonic chip comprising:
• a primary laser;
• a secondary laser;
• an optical coupler connected by first and second optical fibers to the primary and the secondary lasers, respectively, and by a third optical fiber to the first silicon photonic chip, the optical coupler to combine any output from the primary light source and any output from the secondary light source into an input to the silicon photonic chip;
• an optical splitter in the first optical fiber between the primary laser and the optical coupler to divert part of the output from the primary laser;
• and
• a dark sensor connected by a fourth optical fiber to the optical splitter, the dark sensor to receive the diverted part of the output from the primary laser and to selectively activate the secondary laser based on the diverted part of the output from the primary laser.

A method to supply light to a silicon photonic chip, comprising:

• combining any output from a primary light source and any output from a secondary light source into an input to the silicon photonic chip;
• diverting part of the output from the primary light source;
• sensing the diverted part of the output from the primary light source;
• and
• selectively activating the secondary light source based on the sensing.