An optical device includes an optical port array, an optical arrangement, a dispersion element, a focusing element and a programmable optical phase modulator. The optical port array has at least one optical input port for receiving an optical beam and a plurality of optical output ports. The optical arrangement allows optical coupling between the input port and each of the output ports and prevents optical coupling between any one of the plurality of optical output ports and any other of the plurality of optical output ports. The dispersion element receives the optical beam from the input port after traversing the optical arrangement and spatially separates the optical beam into a plurality of wavelength components. The focusing element focuses the plurality of wavelength components. The programmable optical phase modulator receives the focused plurality of wavelength components and steers them to a selected one of the optical outputs.

A method is described in which a database is monitored. The database includes information specifying allocations of time periods in which a first optical carrier corresponding to a first optical channel will not be supplying encoded first data into output optical signals being transmitted from a first node to a second node. An idler carrier being amplified stimulated emission light having a frequency corresponding to the first optical channel is supplied into the output optical signals transmitted from the first node to the second node during the time periods in which the first optical carrier will not be supplying encoded first data into the output optical signals.

A method is described in which a loss of spectrum in an optical signal having an optical signal spectrum is detected. The optical signal is transmitted from a first node to a second node. In response to detecting the loss of spectrum in the optical signal, at least one idler carrier without data imposed is supplied into the optical signal spectrum transmitted from the first node to the second node, the optical signal spectrum encompassing a frequency band including a plurality of optical channels, the idler carrier being amplified stimulated emission light having a frequency corresponding to a first optical channel of the plurality of optical channels.

An optical receiver includes a cascade of optical filtering elements, each of which selects spectral components from incoming optical signals at a wavelengths aligned to filter passbands. The selected spectral components may be optically combined to form k pairs of intermediary signals, where k=log.sub.2(M). By comparing the k pairs of intermediary signals, k bits of a digital signal representing the incident signal may be generated. The filtering elements may be configured to perform demultiplexing and demodulation simultaneously, increasing functionality and reducing excess losses. The filtering elements may also be tuned so that the optical receiver may be reconfigured to accommodate different combinations of wavelengths and modulation formats, such as wavelength division multiplexed (WDM) on off keying (OOK), M-ary orthogonal formats including frequency shift keying (FSK) and pulse position modulation (PPM), differential phase shift keying, and hybrid combinationsproviding rate and format flexibility and WDM scalability.

A fast optical switch can be fabricated/constructed, when a vanadium dioxide (VO.sub.2) and a two-dimensional (2-D) material is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce an insulator-to-metal phase transition (IMT) in vanadium dioxide. 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.

In the wavelength selective switch provided in the present invention, at least one optical element is successively arranged in the wavelength selective switch according to a sequence of processing optical signals. The at least one optical element receives a service optical signal from a service laser, receives a monitoring optical signal from a monitoring laser, and performs same optical signal processing on the service optical signal and the monitoring optical signal according to a processing function of the at least one optical element, where a wavelength of the service optical signal and a wavelength of the monitoring optical signal are different. A service optical signal processed by the at least one optical element and a monitoring optical signal processed by at least one optical element are output, where the monitoring optical signal processed by the at least one optical element is used for monitoring performance of the wavelength selective switch.

A method of pulse width modulating a spatial light modulator comprises determining a modulation sequence and applying the modulation sequence to the spatial light modulator in a time order method. The modulation sequence comprises a plurality of minor modulation segments. Each minor modulation segment comprises an always-on modulation segment in an always-on state. The plurality of minor modulation segments are temporally spaced such that the always-on modulation segments are spaced at predetermined intervals. Each minor modulation segment comprises at least one thermometer bit.

An example embodiment includes a liquid crystal on silicon (LCOS) system. The LCOS system includes multiple pixels, a pixel voltage supply source (voltage source), an external buffer, and a local buffer. The voltage source is configured to supply an analog ramp to the pixels. The external buffer is configured to buffer the voltage source from the pixels. The local buffer is configured to buffer the external buffer from a subset of pixels of the plurality of pixels.

A frequency conversion device includes: an optical convertor configured to convert a source modulated light into an unmodulated light; and a frequency convertor configured to use the unmodulated light converted by the optical convertor as a reference light and convert the source modulated light into a modulated light that has a desirable frequency.

A fast optical switch can be fabricated/constructed, when vanadium dioxide (VO.sub.2) ultra thin-film or vanadium dioxide (VO.sub.2)/two-dimensional (2-D) material 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.