Abstract: A broadband wavelength-division multiplexer comprises two input waveguides for two input signals, each of which is from a different wavelength band, a multi-mode interference waveguide for producing an output wavelength-division multiplexed (WDM) signal comprising the two input signals where at least one of the two input signals is partially coupled to produce the output WDM signal, and an output waveguide for providing the output WDM signal. Optionally, at least another output waveguide can be used to trap all or some power not coupled to produce the output WDM signal.

Abstract: A multimode interference coupler having a tunable power splitting ratio and a method of tuning the splitting ratio. The tuning of the power splitting ratio is achieved by varying an effective refractive index around a portion in a multimode interference section.

Abstract: A broadband wavelength-division multiplexer comprises two input waveguides for two input signals, each of which is from a different wavelength band, a multi-mode interference waveguide for producing an output wavelength-division multiplexed (WDM) signal comprising the two input signals where at least one of the two input signals is partially coupled to produce the output WDM signal, and an output waveguide for providing the output WDM signal. Optionally, at least another output waveguide can be used to trap all or some power not coupled to produce the output WDM signal.

Abstract: A delayed interference all-optical wavelength converter is arranged to convert and reshape a pulsed input signal Pin at &lgr;1 into the wavelength converted signal Pconv at &lgr;2, where &lgr;1 and &lgr;2 are different. A delayed interference all-optical wavelength regenerator is similar, but is arranged to reshape a pulsed input signal Pin into the wavelength converted signal Pconv, where the wavelengths of the input signal and the converted signal are the same. The converter/regenerator comprises an input-signal coupling unit for receiving the pulsed input signal and supplying it to one input of a modulation section, the other input to which is a carrier signal Pcw. The output of the modulation section Pint, which is generally speaking, a phase modulated signal which may also have an amplitude modulated component, is applied to a delay interference section arranged to transform Pint into a primarily amplitude-modulated signal.

Abstract: A method and apparatus for providing optical 3R regeneration involving: 1) generating an encoded optical clock signal from at least an optical signal; 2) introducing the encoded clock signal into a delay interference section of a regenerator such that an amplitude modulated clock signal is produced; andoutputting the amplitude modulated clock signal wherein the output amplitude modulated clock signal preserves information present within the input optical signal.

Abstract: A wavelength converter with a monolithically integrated delay loop in a delayed interference configuration that needs only one SOA or other non-linear optical element coupled to the input fiber, a first coupler to arranged to split the output of the SOA or other non-linear optical amplifying element into two paths having controllable delay and phase shift characteristics, and at least one output coupler to combine the signals present on the two paths to provide the converter output. Unlike prior-art hybrid wavelength converters, one embodiment of the invention has a monolithically integrated delay loop utilizing an asymmetric coupler that can be either the first coupler or the second coupler, or both. Another embodiment of the invention has a coupler that does not require an asymmetric splitting ratio, and has either a gain element in one of the paths, an attenuation element in one of the paths, or both.

Abstract: New, compact optical--optical switches and/or wavelength converters manufacturable with good tolerances and evincing all or some of the following properties,compactnessgood ON/OFF switching ratiospossibility of cascading and bidirectional operationpolarization-independence feasibilityvery fast switchingare being developed.This requires developing components making use of different-order modes to mix the information signal and the control signal and to separate them. The compact Converter Combiner MMIs of the invention make possible:1. converting a first fundamental mode into first-order modes,2. superposing the first-order modes and the images of a second fundamental mode,3. the MMI operates simultaneously as mode splitter for the participating modes.Back-conversion of the generated modes of higher order into their initial modes also is possible.