Abstract: A method for modulating the E-field of an optical carrier signal utilizes a Mach-Zehnder modulator having a pair of independently controllable branches. A pair of independent branch drive signals VL(t) and VR(t) are derived. Each branch of the MZ modulator is driven with a respective one of the independent branch drive signals. By this means, a low cost conventional MZ modulator (interferometer) can be used to perform complex modulation of the E-field of the optical carrier. In some embodiments, this functionality is used to facilitate precompensation of optical impairments of an optical communications system.

Abstract: To support interleaving of optical channels and to provide sufficient isolation between such interleaved channels, a circulator (60-62) receives, on an optical fiber (16-18), a broadband signal containing a plurality of adjacent channels. The circulator selectively routes the broadband signal through a filter (64, 66) to isolate, on an individual basis, at least one desired channel. A filtered signal, corresponding to the at least one desired channel, is then output from the filter (64-66) and reflected back into the filter by a mirror (68-70) such that the at least one desired channel is subjected to a second filtering process that further improves isolation of the at least one desired channel. Following this second filtering process, the at least one desired channel is applied to the circulator (60-62) for re-inserting into the optical fiber (16-18), as illustrated in FIG. 6.

Abstract: Polarization Dependent Effects (PDEs), including Polarization Mode Dispersion (PMD) and Polarization Dependent Loss (PDL) imposed on optical signals conveyed through an optical link are compensated by processing an input signal in the electrical domain prior to transmission. A compensation function is derived that at least partially compensates the PDEs. The communications signal is then processed in the electrical domain using the compensation function to generate an electrical predistorted signal. The electrical predistorted signal is then used to modulate an optical source to generate a corresponding predistorted optical signal for transmission through the optical link. The PDEs of the optical link operate of the predistorted optical signal such at that substantially undistorted optical signal is received at a receiving end of the link.

Abstract: Composite food having a gelling agent, selected from gelatin, egg white, modified waxy maize starch, whey protein concentrate, modified potato starch, gellan gum, and rennet casein, and a flavoring and/or texturing component, uniformly distributed throughout, selected from nonfat dry milk, butter, enzyme modified cheese, BBQ seasoning blend, cheddar cheese, sugars, milk protein concentrate, vinegar, and partially hydrogenated soybean oil, with the remainder of the composite made up primarily of water. The composite food product is substantially solid and self-sustaining at ambient temperature.

Abstract: Composite food having a gelling agent, possibly selected from gelatin, egg white, modified waxy maize starch, whey protein concentrate, modified potato starch, gellan gum, and rennet casein, and a flavoring and/or texturing component, uniformly distributed throughout, possibly selected from nonfat dry milk, butter, enzyme modified cheese, BBQ seasoning blend, cheddar cheese, sugars, milk protein concentrate, vinegar, and partially hydrogenated soybean oil, with the remainder of the composite made up primarily of water. The composite food product is substantially solid and self-sustaining at ambient temperature.

Abstract: Apparatus for superplastically forming large parts from titanium comprising: a furnace (10) having an interior, the inside surface of the furnace (10) being contoured and finished so as to form a mold for the part to be superplastically formed; means (70) for heating the interior of the furnace (10); and a supply (60) of an inert gas. The surface of the mold is adapted to receive a substantially unformed titanium blank (80). The heating means (70) is adapted to heat the titanium blank (80) to the required temperature for superplastic forming. The supply (60) of the inert gas is operable to exert a pressure onto the surface of the titanium blank (80) furthermost from the surface of the mold such that the inert gas causes the titanium blank (80) to deform and take up the shape of the mold, thereby forming the required part.

Abstract: In a WDM transmission system carrying amplitude modulated traffic in which significant cross-phase modulation occurs, each of the individual channels is pre-chirped at the transmitter with replicas, or low-pass filtered replicas of the amplitude modulation applied to each of the other channels. Prechirping of each individual channel with a replica of the amplitude modulation applied to that channel may be added in order additionally to provide compensation for self-phase modulation.

Abstract: An optical amplifier for use in a WDM transmission system has a circulator two of whose ports constitute the input and output ports of the amplifier, and to whose third port is connected an optically amplifying fibre. Bragg grating reflectors are formed at specific intervals along this fibre chosen such that each WDM channel is reflected back to the circulator at a distance in inverse proportion to the gain per unit length experienced by that channel in the amplifier fibre, whereby all channels are amplified by the amplifier to the same extent.