Chip, module, device, and system for optical interconnection

A photonic integrated circuit (PIC) chip, comprising one or more photonic integrated circuit sub-modules, each sub-module comprising:

• a plurality of first optical switching units, each first optical switching unit comprising a first optical input port, a first optical output port, and a second optical output port, and being configured to selectively output an optical signal received at the first optical input port via either the first optical output port or the second optical output port;
• at least one on-chip optical switch comprising a plurality of optical input ports and a plurality of optical output ports, wherein the plurality of optical input ports are respectively optically connected to the second optical output ports of the plurality of first optical switching units, and the at least one on-chip optical switch is configured to selectively output an optical signal received at any one of the plurality of optical input ports via at least one of the plurality of optical output ports;
• a plurality of modulators optically connected to corresponding first optical input ports of the plurality of first optical switching units and configured to modulate information carried by an electrical signal onto the optical signal;
• a plurality of detectors, at least a portion of the plurality of detectors being optically connected to the plurality of optical output ports of the at least one on-chip optical switch;
• a plurality of first optical couplers configured to optically connect the first optical output ports of the plurality of first optical switching units to a first external optical fiber array;
• and
• a second optical coupler optically connected to at least a portion of the plurality of detectors and configured to transmit optical signals from a second external optical fiber array to the portion of the plurality of detectors.