Abstract: An optical switching fabric enables an optical signal entering the device on any one of multiple input ports to be directed to any one of multiple output ports. The present optical switching fabrics include sensing and monitoring devices that permit precise initial calibration and continuous switch connection status monitoring and control. Light entering the switching fabric on an input port is reflected by one of a first set of individually controllable mirrors to one of a second set of individually controllable mirrors and then to a corresponding output port. The switching fabrics include control lasers and position sensing devices which provide output signals corresponding to the orientations of the mirrors. In addition, a subset of the input ports and output ports can be attached to monitor light sources and detectors for recalibration and control.

Abstract: Methods of calibrating and operating optical switches as well as optical switches in which the orientations of mirrors are measured and controlled using control light beams and position sensing detectors are described. The present invention may provide high resolution control of a plurality of mirrors in an optical switch and thus allow the optical switch to cross-connect a large number of input and output ports with a low insertion loss.

Abstract: An optical switching fabric enables an optical signal entering the device on any one of multiple input ports to be directed to any one of multiple output ports. The present optical switching fabrics include sensing and monitoring devices that permit precise initial calibration and continuous switch connection status monitoring and control. Light entering the switching fabric on an input port is reflected by one of a first set of individually controllable mirrors to one of a second set of individually controllable mirrors and then to a corresponding output port. The switching fabrics include control lasers and position sensing devices which provide output signals corresponding to the orientations of the mirrors. In addition, a subset of the input ports and output ports can be attached to monitor light sources and detectors for recalibration and control.

Abstract: A method of controllably attenuating a beam of light coupled into a port includes directing the beam of light against a mirror, and controlling an orientation of the mirror such that a predetermined fraction of the beam of light is coupled into the port. The predetermined fraction is less than a maximum fraction corresponding to optimal coupling of the beam of light into the port. The method may be implemented with a variable optical attenuator including a first port, a second port, a mirror located to direct light output by the first port to the second port, and a controller coupled to the mirror to align it such that the predetermined fraction of light is coupled into the second port. The method may also be implemented with an optical switch.

Abstract: An electro-optic modulator (300) comprises a multiple quantum well core layer (320) in which the band gap and refractive index are adjusted to make the core layer (320) transparent to light at a selected wavelength and a voltage tunable, multiple quantum well cladding layer (330) in which an exciton absorption provides the cladding layer (330) with a first refractive index that is less than the core refractive index when a first voltage is applied and a second refractive index that approaches or exceeds the core refractive index when a second voltage is applied. The exciton absorption also provides the voltage tunable cladding layer (330) with a substantially greater absorption coefficient at the selected wavelength than that of the core layer (320).