A fast optical switch can be fabricated/constructed, when vanadium dioxide (VO.sub.2) ultra thin-film or a cluster of vanadium dioxide particles (less than 0.5 microns in diameter) embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce rapid insulator-to-metal phase transition (IMT) in vanadium dioxide ultra thin-film or vanadium dioxide particles embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires. The applications of such a fast optical switch for an on-Demand optical add-drop subsystem, integrating with or without a wavelength converter are also described.

Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.

A multicast optical switch based on free-space transmission comprises a 1×M input collimator array, a light splitting device, an optical distance compensation device, a spot transformation device, a 1×N output collimator array and a reflector array which are arranged in sequence. The 1×N output collimator array corresponds to reflector array. The light splitting device is provided with a light splitting surface and a reflection surface, and by means of light splitting surface and reflection surface, light splitting and beam splitting of n times are carried out on input signals of 1×M input collimator array, and then N beams of sub-signal light are generated. The optical distance compensation device compensates optical distance differences among M×N sub-signal light beams produced by light splitting device. The M×N sub-signal light beams are focused to be 1×N light spots through light spot conversion device, and then 1×N light spots are reflected to reflector array.

Methods, systems and devices for diffractive waveplate lens and mirror systems allowing electronically pointing and focusing light at different focal planes. The system can be incorporated into a variety of optical schemes for providing electrical control of transmission. In another embodiment, the system comprises diffractive waveplates of different functionality to provide a system for controlling not only focusing but other propagation properties of light including direction, phase profile, and intensity distribution. The diffractive waveplate lens and mirror systems are applicable to optical communication systems.

Optical beam steering and focusing systems, devices, and methods that utilize diffractive waveplates are improved to produce high efficiency at large beam deflection angles, particularly around normal incidence, by diffractive waveplate architectures comprising a special combination of liquid crystal polymer diffractive waveplate both layers with internal twisted structure and at a layer with uniform structure.

An apparatus includes a first input port, a first switch, and a second switch. The first switch and the second input port are in optical communication with the first input port. The apparatus also includes a second input port, a third switch, and a fourth switch. The third switch and the fourth switch are in optical communication with the second input port. Each switch is switchable between a first state to pass optical signals and a second state to block optical signals. The apparatus also includes a first combiner in optical communication with the first input port via the first switch and the second input port via the third switch. The apparatus also includes a second combiner in optical communication with the first input port via the second switch and the second input port via the fourth switch.

Described herein is a diffraction grating (1) for use in an optical system. The diffraction grating includes a substrate (2) and an array of elongate diffracting elements (3) arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.

An apparatus includes a first input port, a first switch, and a second switch. The first switch and the second input port are in optical communication with the first input port. The apparatus also includes a second input port, a third switch, and a fourth switch. The third switch and the fourth switch are in optical communication with the second input port. Each switch is switchable between a first state to pass optical signals and a second state to block optical signals. The apparatus also includes a first combiner in optical communication with the first input port via the first switch and the second input port via the third switch. The apparatus also includes a second combiner in optical communication with the first input port via the second switch and the second input port via the fourth switch.

An apparatus includes a first input port, a first switch, and a second switch. The first switch and the second input port are in optical communication with the first input port. The apparatus also includes a second input port, a third switch, and a fourth switch. The third switch and the fourth switch are in optical communication with the second input port. Each switch is switchable between a first state to pass optical signals and a second state to block optical signals. The apparatus also includes a first combiner in optical communication with the first input port via the first switch and the second input port via the third switch. The apparatus also includes a second combiner in optical communication with the first input port via the second switch and the second input port via the fourth switch.