Optical configuration for a dynamic gain equalizer and a configurable add/drop multiplexer

An optical device comprising:

• a first port for launching a beam of light;
• first redirecting means disposed substantially one focal length away from the first port for receiving the beam of light, the first redirecting means having optical power;
• a dispersive element disposed substantially one focal length away from the first redirecting means for dispersing the beam of light into a plurality of sub-beams of light;
• second redirecting means disposed substantially one focal length away from the dispersive element for receiving the dispersed beam of light, the second redirecting means having optical power;
• and, modifying means optically disposed substantially one focal length away from the second redirecting means for selectively modifying each sub-beam of light and for reflecting each of the modified sub-beams back to the second redirecting means, wherein each sub-beam of light is incident on and reflected from the modifying means along substantially parallel optical paths;
• wherein the modifying means comprises a liquid crystal array and a reflector.

An optical device for rerouting and modifying an optical signal comprising:

• a lens including a first end having a single port coincident with an optical axis thereof and a second end having two ports disposed off the optical axis;
• an element having optical power disposed about one focal length away from the lens for receiving a beam of light launched from the single port;
• a dispersive element disposed about one focal length away from the element having optical power for spatially dispersing a beam of light received therefrom;
• and
• modifying means optically disposed about two focal lengths away from the dispersive element for modifying and reflecting a beam of light spatially dispersed by the dispersive element, wherein said one focal length is a focal length of the element having optical power.

An optical device comprising:

• a first port for launching a beam of light including a plurality of wavelength channels;
• first redirecting means for receiving the beam of light, the first redirecting means having optical power;
• a dispersive element for dispersing the beam of light into the plurality of wavelength channels;
• second redirecting means for receiving the dispersed wavelength channels, the second redirecting means having optical power;
• and
• modifying means for reflecting at least a portion of at least one of the wavelength channels back to a second port via the second redirecting means, the dispersive element and the first redirecting means;
• wherein the first redirecting means and the second redirecting means comprise a single element having optical power.

An optical device comprising:

• a first port for launching a beam of light including a plurality of wavelength channels;
• first redirecting means for receiving the beam of light, the first redirecting means having optical power;
• a dispersive element for dispersing the beam of light into the plurality of wavelength channels;
• second redirecting means for receiving the dispersed wavelength channels, the second redirecting means having optical power;
• and
• modifying means for reflecting at least a portion of at least one of the wavelength channels back to a second port via the second redirecting means, the dispersive element and the first redirecting means;
• wherein the modifying means includes an array of liquid crystal cells for rotating the polarizations of a selected number of wavelength channels by desired amounts.

A method of rerouting and modifying an optical signal comprising the steps of:

• a) launching a beam of light from an input/output port towards an element having optical power off an optical axis thereof;
• b) redirecting the beam of light with the first element having optical power to a dispersive element;
• c) spatially dispersing the redirected beam of light into a plurality of sub-beams of light corresponding to a plurality of different spectral channels with the dispersive element;
• d) redirecting the sub-beams of light with the element having optical power to a modifying means;
• e) selectively modifying at least one of the sub-beams of light, and reflecting them back towards the element having optical power;
• f) redirecting the selectively modified sub-beams with the element having optical power to the dispersive element;
• g) combining the selectively modified sub-beams to form a single output beam of light;
• and
• h) redirecting the output beam of light with the element having optical power to the input/output port.