Wavelength selective switch having multi-layer reflector

A wavelength selective switch (WSS) apparatus comprising:

• a plurality of optical ports configured to output light beams at different angles from one another;
• a wavelength dispersion element configured to disperse the wavelength components of each light beam;
• a focusing element configured to focus the dispersed wavelength components of the light beams;
• and
• a multi-layer reflecting unit configured to reflect the focused light beams to the focusing element, the multi-layer reflecting unit including a multi-layer reflector and a reflection controller operatively connected to the multi-layer reflector, the multi-layer reflector having a main surface for reflecting the light beams on which a plurality of layers are provided, each layer including a plurality of pixels that are individually controllable by the reflection controller,
• wherein the plurality of optical ports comprise N input ports and an output port, where N is a natural number equal to or greater than two, the N input ports being connected to a coupler which is in turn connected to the output port, and wherein the multi-layer reflecting unit is configured to reflect predetermined wavelength components of the light beams to predetermined one of the N input ports and blocks the predetermined wavelength components of the light beams from entering any of the rest N−1 input ports by controlling the plurality of pixels on the multi-layer reflector by the reflection controller.

A wavelength selective switch (WSS) apparatus comprising:

• a plurality of optical ports configured to output light beams at different angles from one another;
• a wavelength dispersion element configured to disperse the wavelength components of each light beam;
• a focusing element configured to focus the dispersed wavelength components of the light beams;
• and
• a multi-layer reflecting unit configured to reflect the focused light beams to the focusing element, the multi-layer reflecting unit including a multi-layer reflector and a reflection controller operatively connected to the multi-layer reflector, the multi-layer reflector having a main surface for reflecting the light beams on which a plurality of layers are provided, each layer including a plurality of pixels that are individually controllable by the reflection controller,
• wherein the plurality of optical ports comprise an input port and M output ports, where M is a natural number equal to or greater than two, the input port being connected to a splitter which is in turn connected to the M output ports, and wherein the multi-layer reflecting unit is configured to reflect predetermined wavelength components of the light beams to predetermined one of the M output ports and blocks the predetermined wavelength components of the light beams from entering any of the rest M−1 output ports by controlling the plurality of pixels on the multi-layer reflector by the reflection controller.

A method of controlling a wavelength selective switch (WSS) apparatus comprising:

• outputting light beams, by a plurality of optical fiber ports, at different angles from one another;
• dispersing the wavelength components of each light beam using a wavelength dispersion element;
• focusing the dispersed wavelength components of the light beams using a focusing element configured to;
• and
• reflecting the focused light beams to the focusing element using a multi-layer reflecting unit, the multi-layer reflecting unit including a multi-layer reflector and a reflection controller operatively connected to the multi-layer reflector, the multi-layer reflector having a main surface for reflecting the light beams on which a plurality of layers are provided, each layer including a plurality of pixels that are individually controllable by the reflection controller,
• wherein the WSS apparatus is arranged that a predetermined wavelength component of a light beam output from one of the optical fiber ports is reflected by the multi-layer reflector to travel back to the one of the optical fiber ports.