Polarization independent optical device

A polarization independent optical device, wherein the polarization independent optical device comprises an input/output preprocessing optical path and M add/drop optical paths, wherein each add/drop optical path comprises a microring and a first polarization splitter and rotator (PSR), and wherein M is greater than 1;

• wherein input ports and throughput ports of M microrings comprised in the M add/drop optical paths are connected in a head-to-tail manner, wherein a first lightwave transmission port of the input/output preprocessing optical path is connected to an input port of a microring comprised in the first add/drop optical path, and wherein a second lightwave transmission port of the input/output preprocessing optical path is connected to a throughput port of a microring comprised in the M-th add/drop optical path;
• wherein the input/output preprocessing optical path is configured to:
• process each of a plurality of optical signals at different wavelengths in an input first wavelength division multiplexing WDM signal to obtain a first QTE and a first PTE;
• and
• transmit a plurality of first QTEs and a plurality of first PTEs that are obtained through processing to the microrings comprised in the M add/drop optical paths, wherein QTE indicates a transverse electric (TE) mode of an optical signal, and wherein PTE indicates a TE polarization mode rotated from a transverse magnetic (TM) mode of the optical signal;
• and
• wherein for any of the M add/drop optical paths, a microring comprised in the add/drop optical path is connected to a first PSR comprised in the add/drop optical path, and wherein:
• the microring comprised in the add/drop optical path is configured to transmit a first QTE of the plurality of first QTEs that meets a resonance condition and a first PTE of the plurality of first PTEs that meets the resonance condition to the first PSR connected to the microring;
• the first PSR comprised in the add/drop optical path is configured to process the received first QTE and the received first PTE, and output the processed first QTE and first PTE;
• and
• the first PSR comprised in the add/drop optical path is further configured to process an input optical signal to obtain a second QTE and a second PTE, and transmit the second QTE and the second PTE to the microring connected to the first PSR;
• the microring comprised in the add/drop optical path is further configured to transmit the second QTE and the second PTE to the input/output preprocessing optical path;
• and
• the input/output preprocessing optical path is further configured to process the received second QTE and the received second PTE, and output the processed second QTE and second PTE.