Abstract: A multimode interference device and a method of configuring the same comprises a multimode interference region having a major axis; and a plurality of ports connected to a side portion of the multimode interference region, wherein the side portion is positioned in a direction other than perpendicular to the major axis.

Abstract: A radio frequency (RF) to optical converter for RF imaging, wherein the converter comprises an array of RF antenna pixels adapted to receive RF signals, wherein the RF antenna pixels are adapted to facilitate RF resonance of the received RF signals; a photonic band gap (PBG) layer connected to the array of RF antenna pixels, the PBG layer comprising at least two materials, arranged in a photonic crystal (PC), wherein at least one of the materials comprises an electro-optic (EO) material, wherein the EO material is adapted to use the RF resonant signals to produce changes in optical properties of the EO material, and wherein the PC is adapted to use changes in optical properties of the EO material to produce enhanced changes in optical properties of the PBG layer; and an RF ground plane connected to the PBG layer.

Abstract: A multimode interference device and method of making the same comprises at least one input port, at least one output port, a multimode interference region separating the input port from the output port, and at least one subregion in the multimode interference region, wherein a self-image length within the multimode interference region is reduced by a factor that is approximately equal to one plus a number of subregions configured in the multimode interference region, wherein the at least one subregion is configured to have an effective width and effective refractive index running longitudinally through the multimode interference region. Additionally, the subregion may comprise at least one slot.

Abstract: The invention discloses devices and methods of manufacturing devices for the splitting and amplification of light signals by use of an end-pumped waveguide optical device, based on either (a) self-imaging multiplexing of the signal and pump light, then amplification of the signal, then simultaneous self-imaging splitting of the signal and demultiplexing of the signal and pump, then separation of the signal outputs via nonamplifying S-bends; or (b) self-imaging multiplexing of the signal and pump light, then amplification of the signal, then splitting of both signal and pump, then separation of the outputs via amplifying S-bends, and then finally self-imaging demultiplexing of the signal and pump light in each output.

Abstract: Three new techniques for the separation of orthogonally polarized light or ight of 2 arbitrary wavelengths by use of a waveguide optical device, based on either 1) simultaneous 1-by-1 and 1-by-2 self-imaging, or 2) simultaneous crossed and barred 1-by-1 off-center self-imaging, or 3) out-of-phase self-imaging. Simultaneous 1-by-1 and 1-by-2 self-imaging utilizes a waveguide optical polarization splitter having an input waveguide containing TE and TM, a multimode interference region, aligned so that TE and TM refractive indices are very different, and with the length set so that the polarization with the lower refractive index is singly self-imaged while the other polarization is doubly self-imaged, an output waveguide containing polarization with higher refractive index, and two additional output waveguides each containing half the power of the other polarization.

Abstract: Two new techniques for the separation of orthogonally polarized light or ht of 2 arbitrary wavelengths by use of a waveguide optical device, based on either 1) simultaneous crossed and barred 1-by-1 off-center self-imaging, or 2) out-of-phase self-imaging. Simultaneous crossed and barred 1-by-1 off-center self-imaging utilizes a waveguide optical polarization splitter having an input waveguide containing TE and TM, a multimode interference region, aligned so that TE and TM refractive indices are very different, and with the length set so that the polarization with the lower refractive index is bar self-imaged while the other polarization is cross self-imaged, an output waveguide containing polarization with higher refractive index, and another output waveguide containing the other polarization. Both of these methods may also be used to separate light of 2 arbitrary wavelengths.

Abstract: A process for peroxide bleaching of mechanical pulps by washing the pulp to remove substantially all of the heavy metal ions from the pulp, mixing hydrogen peroxide in an amount of at least about 11/2% based on the dry weight of the pulp with the washed pulp to uniformly disperse the hydrogen peroxide throughout the pulp followed by mixing an aqueous solution of sodium hydroxide with the pulp containing hydrogen peroxide to uniformly distribute the sodium hydroxide throughout the pulp and to react the sodium hydroxide with the peroxide to produce perhydroxyl ions in situ in the pulp and then reacting the perhydroxyl ions with the pulp to increase the brightness of the pulp and provide a residual peroxide of at least 35% of the peroxide added. This system provides a significant increase in residual brightening chemical in the residual liquor separated from the brightened pulp.

Abstract: A two-stage chemical treatment process is disclosed for increasing the density, strength and brightness properties of mechanical wood pulp. The method comprises the steps of: applying an aqueous solution of sodium sulfite in the range of about 1%-10% sodium sulfite based on bone dry weight of wood to wood particles, the solution having a pH in the range of about 4.5-11; heating the sodium sulfite treated wood particles to a temperature in the range of about 100.degree.-160.degree. C.

Abstract: A method is described for increasing the yield of pulp obtained from an alkaline pulping process. A lignocellulosic material, such as wood chips, is first pretreated with an aqueous solution containing from 0.1 to 10% by weight of monoethanolamine, methylamine or dimethylamine and from 0.01 to 1% by weight of copper sulfate or nickel sulfate at elevated temperature and pressure in a closed vessel. This pretreated material is then subjected to conventional alkaline pulping, preferably soda or two-stage soda-oxygen pulping.

Abstract: A method is described for increasing the yield of pulp obtained from an alkaline pulping process. A lignocellulosic material, such as wood chips, is first pretreated with an aqueous solution containing from 0.1 to 10% by weight of monoethanolamine, methylamine or dimethylamine and from 0.01 to 1% by weight of copper nitrate or nickel nitrate at elevated temperature and pressure in a closed vessel. This pretreated material is then subjected to conventional alkaline pulping, preferably soda or two-stage soda-oxygen pulping.