Optical switching apparatus, redirection method, and reconfigurable optical add-drop multiplexer

A redirection method, applied to an optical switching apparatus, which comprises an input port, a dispersion grating, a first lens assembly, a redirection assembly, and an output port, and the method comprises:

• inputting a first beam into the dispersion grating at a first angle of incidence in a first direction by the input port cooperating with a plurality of lenses;
• inputting a second beam into the dispersion grating at a second angle of incidence in the first direction through the input port, wherein a difference between absolute values of the first angle of incidence and the second angle of incidence is non-zero;
• dispersing the first beam by using the dispersion grating to form a plurality of first sub-beams;
• dispersing the second beam by using the dispersion grating to form a plurality of second sub-beams;
• focusing the plurality of first sub-beams and the plurality of second sub-beams to the redirection assembly by using the first lens assembly,
• wherein the redirection assembly includes at least one of a liquid crystal array chip, or a micro-electro-mechanical system (MEMS);
• wherein the plurality of first sub-beams are incident on a first region of the redirection assembly, the plurality of second sub-beams are incident on a second region of the redirection assembly,
• wherein the difference between the absolute values of the first angle of incidence and the second angle of incidence enables the first region and the second region to be separated from each other in the first direction, and enables the first region and the second region to at least partially overlap in a second direction,
• wherein the first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to a propagation direction of the first beam;
• and
• outputting, through the output port, the plurality of first sub-beams and the plurality of second sub-beams that are redirected by the redirection assembly;
• wherein the optical switching apparatus further comprises a third lens assembly positioned between the input port and the dispersion assembly, and at least one of the first angle of incidence and the second angle of incidence depends on a position of the third lens assembly;
• and
• wherein at least one of the first angle of incidence and the second angle of incidence depends on a distance between the input port and a primary optical axis of the third lens assembly.

A reconfigurable optical add-drop multiplexer, comprising a plurality of optical switching apparatuses, wherein different optical switching apparatuses are connected to each other by using an optical fiber, and at least one of the optical switching apparatuses comprises an input port, a dispersion grating, a first lens assembly, a redirection assembly, and an output port;

• wherein
• the input port is configured to cooperate with a plurality of lenses to input a first beam into the dispersion grating at a first angle of incidence in a first direction, the input port is further configured to input a second beam into the dispersion grating at a second angle of incidence in the first direction, and a difference between absolute values of the first angle of incidence and the second angle of incidence is non-zero;
• the dispersion grating is configured to disperse the first beam to form a plurality of first sub-beams, and the dispersion grating is further configured to disperse the second beam to form a plurality of second sub-beams;
• the first lens assembly is configured to focus the plurality of first sub-beams and the plurality of second sub-beams to the redirection assembly, the plurality of first sub-beams are incident on a first region of the redirection assembly,
• wherein the redirection assembly includes at least one of a liquid crystal array chip, or a micro-electro-mechanical system (MEMS);
• wherein the plurality of second sub-beams are incident on a second region of the redirection assembly,
• wherein the difference between the absolute values of the first angle of incidence and the second angle of incidence enables the first region and the second region to be separated from each other in the first direction, and enables the first region and the second region to at least partially overlap in a second direction,
• wherein the first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to a propagation direction of the first beam;
• and
• the output port is configured to output the plurality of first sub-beams and the plurality of second sub-beams that are redirected by the redirection assembly;
• wherein the optical switching apparatus further comprises a third lens assembly positioned between the input port and the dispersion assembly, and at least one of the first angle of incidence and the second angle of incidence depends on a position of the third lens assembly;
• and
• wherein at least one of the first angle of incidence and the second angle of incidence depends on a distance between the input port and a primary optical axis of the third lens assembly.