207 results about "Single mode waveguides" patented technology

A tapered rib waveguide tapering from a large, multi-mode optical waveguide to a smaller, single-mode optical waveguide, the tapered rib waveguide comprising two portions (4,5) formed of the same material: a lower portion (4) which tapers laterally from the large waveguide to the smaller waveguide and an upper portion (5) formed on the lower portion (4), which tapers to a point (or other form of termination), the dimensions of the two portions (4,5) being such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide.

An improved fiber-optic communications system comprises a multi-mode waveguide carrying an optical signal, a single-mode waveguide optically coupled to and receiving the optical signal from the multi-mode waveguide and an adiabatic coupler optically coupled between the multi-mode waveguide and the single-mode waveguide. The multi-mode and single-mode waveguides may be optical fibers. The adiabatic coupler may comprise a tapered core surrounded by a cladding. Alternatively, the adiabatic coupler may comprise a core surrounded by a cladding, wherein the refractive index of at least one of the core and the cladding varies over the length of the adiabatic coupler.

In one embodiment, a waveguide lens of the invention has a pair of planar waveguides, e.g., a single-mode waveguide connected to a multimode waveguide. The widths of the two waveguides and the length of the multimode waveguide are selected such that particular mode coupling between the waveguides and multimode interference (MMI) effects in the multimode waveguide cause the latter to output a converging beam of light similar to that produced by a conventional waveguide lens. Advantageously, waveguide lenses of the invention may be used to implement low-loss, low-crosstalk waveguide crossings and/or compact waveguide turns. In addition, waveguide lenses of the invention can be readily and cost-effectively incorporated into waveguide devices designated for large-scale production.

A semiconductor laser device capable of providing high output power operation is provided which has a structure in which high output power and kink suppression can be simultaneously attained as well as these characteristics can be realized by a short chip length. In a waveguide structure of an MMI laser diode, a taper waveguide is intentionally inserted between a single mode waveguide and a multimode waveguide, and further, a single mode waveguide is used as a passive waveguide. These individual units or combination thereof can solve the above-described problems.

An optical waveguide including a single-mode waveguide in which an induced radiation ray generated by exciting the ion propagates in a single-mode in both of a thickness direction and a width direction in the single-mode waveguide; and multi-mode waveguides disposed along both of side surfaces of the single-mode waveguide in which the ray propagates in a single-mode in a thickness direction of the multi-mode waveguide and propagates in a multi-mode in a width direction. In accordance with the present invention, the exciting ray is easily absorbed because the ray propagates to cross the single-mode waveguide without a skew-mode propagation, and the laser and the photo-amplifier which can obtain a higher output in the single-mode is provided.

The invention discloses a mode add-drop multiplexing and demultiplexing device based on a grating-assisting type coupler. The device comprises three add single-mode waveguides, an add mode converter, a bus multi-mode waveguide, two add Bragg waveguide gratings, a drop mode converter, three drop single-mode waveguides, two drop Bragg waveguide gratings, two add coupling areas and two drop coupling areas. The Bragg waveguide gratings are arranged between the bus multi-mode waveguide and the add and drop single-mode waveguides, and the energy exchange between the multi-mode waveguide and the single-mode waveguides is realized due to the micro-interference function of the refraction rate. The device has the advantages that the coupling is realized between the single-mode waveguides and the multi-mode waveguide in different modes; the coupling coefficient is adjustable, the bandwidth is large, the number of information carrying channels is multiple, and the like; the design structure is simple, and the size is compact; the device manufacturing process is compatible with a CMOS (complementary metal oxide semiconductor) process, so the integration and the extension are easy, the low-cost manufacturing is convenient, and the device can be widely applied to the on-chip and high-density integrated type optical interconnection system.

An optical device is disclosed which includes a single-mode waveguide (700) which supports a first optical mode in a first region and a second optical mode in a second region. The waveguide includes a guiding layer (703) having at least one wing (750) extended outwardly from the guiding layer (703). The guiding layer (703) may desirably have a rib waveguide (706, 707) cross sectional shape at the wings. The wings (750) decrease in width along the length of the guiding layer to convert a rib waveguide mode at the wings to a channel waveguide mode.

The invention discloses an adjustable-bandwidth filter based on a silicon-based waveguide optical grating. The filter comprises a two-stage optical grating filter. A left downloading end of the first-stage optical grating filter is connected with an input single-mode waveguide of the second-stage optical grating filter. A right direct-connection end of the second-stage optical grating filter is connected with the lower port of a right asymmetric gradual-change directional coupler of the first-stage optical grating filter, thereby achieving the signal recycling. The cascading of the filter is employed for adjusting the range of an overlapping range of two-stage optical grating spectral lines through a thermode, thereby forming the filter. The filter employs the asymmetric gradual-change directional coupler, so the filter is large in tolerance and is small in insertion loss. Based on the optical grating filters, the bandwidth adjustment range is not limited by FSR. The asymmetric gradual-change directional coupler is used for enabling a signal of the direct-through end of the second optical grating filter to be uploaded and synthesized in a no-loss manner, thereby achieving no bandwidth loss. The filter is manufactured through the technology of planar integrated optical waveguides, is formed through one-time etching, is low in cost, is high in performance, and is small in loss.

The invention relates to a photorefractive long-period waveguide grating filter, which comprises input tail fiber and output tail fiber. The photorefractive long period waveguide grating filter further comprises a photorefractive long period waveguide grating that comprises a substrate. The substrate is a LiNbO3 crystal that is tangential in X or Y direction and conductive in Z direction and a cladding is arranged on the substrate. A Z-directional single mode waveguide is arranged on the cladding. A photorefractive holographic grating is manufactured on the single mode waveguide. Two end surfaces of the single mode waveguide are respectively connected with the input tail fiber and the output tail fiber. The invention further provides a manufacturing method of the photorefractive long-period waveguide grating filter. The photorefractive long-period waveguide grating filter has a simplified structure, is convenient to manufacture and has higher recycle rate of materials.

An interface device includes a body portion having a single-mode waveguide portion including a substantially optically transparent material, a cladding portion defined by channels contacting the waveguide portion, the cladding portion including a substantially optically transparent polymer material, an engagement feature operative to engage a portion of a wafer, and a guide portion operative to engage a portion of an optical fiber ferrule.

The present invention discloses a filter based on axial direction apodized grating. Input single mode waveguide is connected with the upper end port of the left end of an asymmetrical gradual changing directional coupler through input gradual changing waveguide, and the lower end port of the left end of the asymmetrical gradual changing directional coupler is connected with bending waveguide to realize reflection signal download; and the upper end port of the right end of the asymmetrical gradual changing directional coupler is connected with the left end of an antisymmetrical multimode waveguide grating, and the right end of the antisymmetrical multimode waveguide grating is connected with the output single mode waveguide through output gradual changing waveguide. The separation of grating reflection signals employs the asymmetrical gradual changing directional coupler with large tolerance and small insertion loss to realize download of the grating signals; based on a grating filter, the filter based on axial direction apodized grating is large in tolerance and wide in bandwidth regulation range and cannot be limited by the FSR so as to realize filters with various different bandwidth demands; and moreover, the axial direction position regulation of grating teeth realizes apodization so as to realize a grating filter with large sideband suppression ratio and greatly improve the performance of the grating filter.

A semiconductor optical amplifier wherein poalization independent gain, high saturation input light intensity, and high saturation gain are obtained. The semiconductor optical amplifier of the present invention comprises a 1x1 multi mode interference (MMI) light waveguide region and a couple of single mode waveguide regions, each of which is connected with each end of the multi mode region. The length of the multi mode waveguide region is about 340 mu m and the length of the single mode waveguide regions is about 20 mu m. The width of the multi mode waveguide region is about 12 mu m while the widths of the single mode waveguide regions 2,3 are about 1 mu m.

An optical characterization device has a guiding body and a diffractive structure integrated with it. The guiding body delivers radiation to the diffractive structure at a preselected angle and the diffractive structure diffracts at least a portion of radiation guided to it to give spatial resolution according to wavelength. A position sensitive detector detects the position of the spatially resolved radiation and thus the radiation can be characterized according to wavelength. Embodiments can be used to monitor and adjust the wavelength of a radiation source, using a feedback connection. By using the integrated approach, a very small structure can be realized and the structure can be relatively simply fabricated and assembled. The guiding body might be either capable of supporting multimode propagation of the radiation or might be a single mode waveguide. Where it is capable of supporting multimode propagation, an input to the guiding body acts to select a mode for propagation of the radiation.

A 1×N fanout waveguide detector is disclosed. The detector includes a multiple-mode interference (MMI) cavity with input and output ends. A single-mode waveguide is optically coupled to the input end of the MMI cavity so that the optical power in the guided mode is distributed over N modes. The MMI cavity forms N interference nodes at or near its output end. N waveguide detectors are optically coupled to the output end at or near the N interference nodes. The waveguide detectors each have a waveguide that is evanescently coupled to an intrinsic region of a PIN detector. The width of the detector waveguide core, which can be sub-micron, defines the carrier collection distance between the electrodes of the PIN detector. Further, the length of the detector waveguide can be selected to maximize optical absorption to provide optimum quantum efficiency. The waveguide detectors are connected in parallel to provide a high-output photocurrent.

The invention discloses a blended crossing device for a silicon-based nanowire. The crossing device comprises two groove waveguide mode switching units, two slab waveguide mode switching units, a sine switching waveguide and a crossing multimode waveguide, wherein the two groove waveguide mode switching units and the two slab waveguide mode switching units are respectively connected through the sine switching waveguide and the crossing multimode waveguide, each groove waveguide mode switching unit is opposite to one slab waveguide mode switching unit, each groove waveguide mode switching unit comprises a groove waveguide for inputting an optical signal and a mode switcher, each mode switcher is connected between each groove waveguide and the sine switching waveguide, each slab waveguide mode switching unit comprises a slab waveguide and a single-mode waveguide for outputting the optical signal, and each single-mode waveguide is connected between each slab waveguide and the sine switching waveguide. The crossing device has the advantages of high transmission efficiency, compact structure, low loss, low manufacturing difficulty, relatively low cost and the like.

The invention discloses an add/drop filter based on an antisymmetric multimode Bragg waveguide grating. When TE light is input from a single-mode input waveguide, a drop asymmetric Y-branch waveguide converts the TE light into a TE fundamental mode of a multimode waveguide; the antisymmetric Bragg waveguide grating carries out back-coupling on the incident light meeting phase matching condition wavelength to form reflected light; the reflected light is converted into a TE mode of a drop single-mode waveguide when passing through the drop asymmetric Y-branch waveguide, and the TE mode is output from the drop end; transmission light passes through an add asymmetric Y-branch waveguide and is output from a single-mode output waveguide; similarly, add light is input from an add single-mode input waveguide; the add asymmetric Y-branch waveguide converts the add light into a TE first-order mode of the multimode waveguide; and the antisymmetric Bragg waveguide grating enables the reflected light meeting the phase matching condition wavelength to be converted into a TE mode of the single-mode output waveguide when the reflected light passes through the add asymmetric Y-branch waveguide, and the TE mode is output from the output end. The add/drop filter realizes signal adding/dropping function, and can be applied to an on-chip super-integrated optical interconnection system.

The invention discloses a mode beam-splitting converter based on a grating-assisted coupler. The converter comprises a single-mode input waveguide, an input mode converter, a bus multi-mode waveguide, a downlink Bragg waveguide grating, an output mode converter, a single-mode output waveguide, a downlink single-mode waveguide and a downlink coupling zone, wherein the input mode converter converts a TM (transverse magnetic) mode in the single-mode input waveguide into a TE (transverse electric) first-order mode in the bus multi-mode waveguide, and by the aid of the Bragg waveguide grating assisted coupler, the TE first-order mode of the multi-mode waveguide and the TE mode of the single-mode waveguide exchange energy. The converter realizes separation of the TE mode and the TM mode which are transmitted in the waveguide, converts the TM mode into the TE mode and has the advantages of simple structure, compactness, large work bandwidth, low crosstalk and the like, the production technology has CMOS (complementary metal-oxide-semiconductor) technology compatibility, the device is easy to integrate and extend, low-cost production is facilitated, and the device can be widely applied to on-chip high-density-integrated optical interconnection systems.