Spectrum processing apparatus and reconfigurable optical add-drop multiplexer

A reconfigurable optical add-drop multiplexer (ROADM), comprising a transmitter, a receiver, and an apparatus, wherein

• the transmitter is configured to add a first local optical wavelength signal to a port assembly of the apparatus;
• the receiver is configured to drop a second local optical wavelength signal from the port assembly of the apparatus;
• and
• the apparatus comprises:
• the port assembly, a lens assembly, a dispersive assembly, a spatial light modulator (SLM), and a reflective element, wherein the port assembly comprises N ports, and the lens assembly comprises M lenses, wherein the M lenses are zoom lenses, wherein N is an integer greater than 1, and M is an integer greater than or equal to 1 and less than or equal to N;
• and
• wherein:
• each port in the port assembly is configured to transmit an input first light beam to a lens in the lens assembly corresponding to the respective port in the port assembly;
• each lens in the lens assembly is configured to adjust a width of the first light beam to obtain a second light beam, and transmit the second light beam to the reflective element;
• the reflective element is configured to reflect each second light beam to the dispersive assembly;
• the dispersive assembly is configured to decompose each second light beam into a plurality of sub-wavelength light beams, and transmit each plurality of sub-wavelength light beams to the reflective element;
• the reflective element is further configured to reflect each plurality of sub-wavelength light beams to the SLM;
• the SLM is configured to modulate each plurality of sub-wavelength light beams, and reflect at least one modulated sub-wavelength light beam to the reflective element;
• the reflective element is further configured to reflect the at least one modulated sub-wavelength light beam to the dispersive assembly;
• and
• the dispersive assembly is further configured to multiplex the at least one modulated sub-wavelength light beam, and transmit a multiplexed light beam to the port assembly through the reflective element and the lens assembly.

A method, wherein the method comprises:

• transmitting, using a first port of a port assembly of an apparatus, a third light beam to a first lens in a lens assembly of the apparatus corresponding to the first port, wherein the first lens comprises a zoom lens;
• using the first lens, adjusting a width of the third light beam to obtain a fourth light beam, and transmitting the fourth light beam to a reflective element of the apparatus;
• reflecting, using the reflective element, the fourth light beam to a dispersive assembly of the apparatus;
• using the dispersive assembly, decomposing the fourth light beam into a first plurality of sub-wavelength light beams, and transmitting the first plurality of sub-wavelength light beams to the reflective element;
• reflecting, using the reflective element, the first plurality of sub-wavelength light beams to a spatial light modulator (SLM) of the apparatus;
• using the SLM, modulating the first plurality of sub-wavelength light beams, and reflecting at least one modulated sub-wavelength light beam to the reflective element;
• reflecting, using the reflective element, the at least one modulated sub-wavelength light beam to the dispersive assembly;
• and
• using the dispersive assembly, multiplexing the at least one modulated sub-wavelength light beam, and transmitting a multiplexed light beam to the port assembly through the reflective element and the lens assembly.