Signal monitoring method and apparatus for wavelength selective switch wss

A wavelength selective switch (WSS), comprising:

• an input port, an incidence grating, an input-end spherical lens, a first optical engine, a second optical engine, an output-end spherical lens, an output-side grating, and a plurality of output ports, wherein:
• the input port is configured to send a received wavelength division multiplexed (WDM) signal to the incidence grating;
• the incidence grating is configured to respectively diffract signals of wavelengths in the received WDM signal to the input-end spherical lens at different diffraction angles;
• the input-end spherical lens is configured to direct the signals of wavelengths to be incident, in parallel, to different positions or areas on the first optical engine;
• the first optical engine is configured to:
• perform phase encoding modulation based on the input port corresponding to the signals of wavelengths, and output the signals of wavelengths to the output-end spherical lens at different angles, and
• split a signal of a wavelength in the signals of wavelengths into a transmitted signal and a monitored signal, and output the transmitted signal and the monitored signal at different emergence angles towards the output port for input to the output-spherical lens;
• the output-end spherical lens is configured to output the signals of wavelengths to the output-side grating and output the monitored signal to the second optical engine;
• the output grating is configured to output the signals of wavelengths to the output ports;
• and
• the second optical engine is configured to:
• determine, in the monitored signal, monitored light of a specified wavelength that currently needs to be monitored, and
• rotate in a wavelength plane of the WDM signal based on an incidence angle at which the monitored light is incident to the second optical engine and an emergence angle at which the monitored light is output from the second optical engine and output the monitored signal at a preset angle.

A signal monitoring apparatus, comprising:

• a wavelength selective switch (WSS) comprising an input port, an incidence grating, an input-end spherical lens, a first optical engine, an output-end spherical lens, an output-side grating, and an output port, and the WSS further comprises a second optical engine disposed at the output-side grating, wherein the second optical engine is configured to separate out monitored light of a specified wavelength to be monitored;
• and
• a processor configured to:
• encode a phase of the first optical engine based on a WDM signal received from the input port to split the WDM signal into a transmitted signal and a monitored signal and output the transmitted signal and the monitored signal at different emergence angles towards the output port, wherein the monitored signal is input to the second optical engine, and energy of the transmitted signal is greater than energy of the monitored signal,
• determine, in the monitored signal, the monitored light of the specified wavelength that currently needs to be monitored;
• and
• control, based on an incidence angle at which the monitored light is incident to the second optical engine and an emergence angle at which the monitored light is output from the second optical engine, the second optical engine to rotate in a wavelength plane of the WDM signal and output the monitored light at the emergence angle.