Embedded faraday rotators and components for increasing bandwidth and/or reducing fiber count in photonics multi chip packages

A photonics patch, comprising:

• a patch substrate;
• a photonics die over the patch substrate;
• a compute die over the patch substrate and communicatively coupled to the photonics die by a bridge embedded in the patch substrate;
• a splitter below the photonics die, wherein the splitter is configured to split an incoming optical signal into a first optical signal and a second optical signal;
• a first optical path from the splitter to the photonics die for propagating the first optical signal;
• a second optical path from the splitter to the photonics die for propagating the second optical signal;
• a third optical path from the photonics die to a multiplexer for propagating the first optical signal;
• and
• a fourth optical path from the photonics die to the multiplexer for propagating the second optical signal, wherein a Faraday rotator is provided along the fourth optical path to convert the second optical signal from a first mode to a second mode.

A photonics patch, comprising:

• a patch substrate;
• a photonics die over the patch substrate;
• a transmit chain, wherein the transmit chain is configured to split an incoming optical signal into a first optical signal and a second optical signal, and wherein the second optical signal is converted from a first mode to a second mode by a first Faraday rotator;
• and
• a receive chain, wherein the receive chain is configured to split a multiplexed signal into a third optical signal propagating at the first mode and a fourth optical signal propagating at the second mode, and wherein a second Faraday rotator converts the fourth optical signal to the first mode before reaching the photonics die.

An electronic system, comprising:

• a board;
• an interposer over the board;
• and
• a patch over the interposer, wherein the patch comprises:
• a patch substrate;
• a photonics die;
• a transmit chain, wherein the transmit chain comprises:
• a splitter to split an incoming optical signal into a first optical signal and a second optical signal;
• a Faraday rotator to convert the second optical signal from a first mode to a second mode;
• and
• a multiplexer to combine the first optical signal with the second optical signal to propagate along a single optical fiber.