235 results about "Multimode interference" patented technology

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.

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 hybrid optoelectronic device and method of producing the hybrid device in which the hybrid device includes a substrate with an input region configured to accept input light, a sol-gel glass multimode interference region coupled to and contiguous with the input region and configured to accept and replicate the input light as multiple self-images, and a sol-gel glass output region contiguous with the multimode region and configured to accept and to output the multiple self-images. Alternatively, the hybrid optoelectronic device includes a substrate with a photoelectronic device, a surface resonator including a light-emitting part of the photelectronic device and configured to resonate light from the photoelectronic device to produce a laser light, and a grating outcoupler contiguous with the surface resonator and configured to diffract the laser light outward from the grating outcoupler and to electrically vary an index of refraction of the outcoupler and change a direction of the diffracted laser light.

An optical device comprises a semiconductor structure including first and second ridge waveguides, each waveguide comprising a ridge extending across a surface of the semiconductor structure. The ridge of the first waveguide has a first height above a first region of the surface, and the ridge of the second waveguide has a second, greater, height above a second region of the surface. The semiconductor structure includes a multimode interference (MMI) region situated between the first and second ridge waveguides, which provides a transition between them. At least a part of the MMI region is tapered in width and/or at least a part of the first and/or second ridge waveguide is tapered in width in a direction extending away from the MMI region.

The present invention provides an optical apparatus having a multimode interference coupler configured to optically couple a strip waveguide to a slot photonic crystal waveguide. The multimode interference coupler has a coupling efficiency to the slot photonic crystal waveguide greater than or equal to 90%, a width that is approximately equal to a defect width of the slot photonic crystal waveguide, a length that is equal to or less than 1.5 μm, and interfaces with the slot photonic crystal waveguide at an edge of a period that gives a termination parameter of approximately zero. The optical apparatus may also include an insulation gap disposed between the multimode interference coupler and the slot photonic crystal waveguide, wherein the length of the multimode interference coupler is reduced by approximately one half of a width of the insulation gap.

An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.

The invention discloses a mixed polarization beam splitter based on photon crystal/multimode interference coupler, comprising multimode interference coupler whose one end is connected with input waveguide and TE output waveguide and whose other end is connected with TM output waveguide and which is inserted with photon crystal layer. And the invention combines the multimode interference coupler with the photon crystal, uses the photon crystal layer to reflect and transmit TE and TM, respectively, and then respectively collects energies of TE and TM polarization through the self-imaging principle of multimode interference region and outputs them from different output waveguides so as to implement polarization beam splitting. And its structure is compact and the whole device can be 50 mu m *20 mu m sized, and output and input use the traditional waveguides, and it is extremely easy to integrate with other devices.

The invention discloses a cross waveguide based on a linear tapered multimode interference principle. The cross waveguide comprises a vertical portion and a horizontal portion, each of the vertical portion and the horizontal portion is composed of a front straight waveguide area, a front tapered waveguide area, a tapered multimode interference area, a rear tapered waveguide area and a rear straight waveguide area which are sequentially connected, the horizontal portion and the vertical portion are perpendicularly crossed, and a crossed area is located in the tapered multimode interference area. The cross waveguide based on the linear tapered multimode interference principle has the advantage of being low in loss and crosstalk and small in size.

A multimode interference splitter/combiner that includes a monolithic device for photonically coupling an input optical waveguide to first and second output optical waveguides. The input waveguide may be optically coupled to a first end of a MMI portion, while the first and second output waveguides may be optically coupled to a second end of the MMI portion. The input waveguide is coupled to a planar facet of the MMI portion so that the input waveguide may have a propagation axis that is oriented at an angle with respect to the planar facet of the MMI portion. A desired splitting ratio may be achieved by adjusting the angle between the input waveguide and the MMI portion.

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.

The present invention comprises an arrayed waveguide grating member, a taper multimode interference coupler and a taper optical attenuator to uniform and flatten a passband in an optical device.

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.

The invention relates to an InP-based mode division multiplexer/demultiplexer structure based on a multimode interference coupler. The structure mainly comprises three parts which are a multimode interference coupler based mode conversion and separation structure, Pi/2 phase shift structure and a multimode interference coupler based 3dB coupler structure. In the Pi/2 phase shift structure, a transmission mode in a waveguide is enabled to be changed in phase shift through tuning the thickness of a waveguide core layer, and the phase shift change reaches Pi/2 when the length of the waveguide is a certain specific value. The mode multiplexer/demultiplexer structure has the advantages of compact structure, small device size, large channel bandwidth, low insertion loss and low channel crosstalk, and is simple in production process and high in production tolerance, thereby being very suitable for monolithic integration with devices such as a semiconductor laser, a modulator, an amplifier, a detector and the like, and being a key device for studying a mode division multiplexing technology based monolithic integration few-mode optical communication transmitting and receiving module.

The invention discloses a multimode interference biological chemical sensor based on silicon slot waveguides, which is characterized by comprising an input waveguide (1), two output waveguides, namely, a first output waveguide (3) and a second output waveguide (4), and a multimode interference waveguide (5), wherein the input waveguide (1) is used for inputting optical signals, the input waveguide (1) is connected with the first output waveguide (3) and the second waveguide (4) through the multimode interference waveguide (5), the multimode interference waveguide (5) is tapered, single wavelength optical signals are input through the input waveguide (1) and subjected to multimode interference in an area of the multimode interference waveguide (5), input lights are subjected to self-imaging length regeneration on the basis of the self-imaging effect of multimode interference, and the self-imaging length is selected as the length of the sensor. The multimode interference biological chemical sensor based on silicon slot waveguides has the advantages of compact structure, insensitive polarization, high bandwidth, good fabrication tolerance and large working range.

A Mach ¿C Zehnder light intensity modulator with microring in non ¿C balance coupling type is prepared as connecting one end of two interference arms to one end of beam splitting couple structure with its one end being connected to input waveguide and another end of two said arms to one end of beam combining interference structure with its another end being connected to output waveguide; setting light microring on one side of any interference arm ; applying Y branch, X node, directional coupler or multimode interference coupler on two said structures separately .

An InP-based wavelength division-mode division multiplexing few-mode communication photon integrated emission chip includes: multiple single-mode semiconductor lasers with different wavelengths, the semiconductor lasers serving as light sources; multiple multimode interference couplers (MMI) having different functions and used for optical power distribution, mode conversion and multi-wavelength multimode multiplexing; and multiple modulator structures for modulation of basic mode signals. The above parts are connected through straight waveguides or bent waveguides. The excellent characteristics of the multiple multimode interference couplers are that the couplers exhibit great design and technical tolerance, have great optical bandwidth, are insensitive to polarization, are small in size, etc. The multimode interference couplers are utilized to serve as multi-wavelength multimode couplers for the first time, wavelength division multiplexing and mode division multiplexing are combined, and thus the fiber transmission capacity is further improved.

An embodiment of the invention discloses a frequency mixer, which comprises a polarized light input waveguide, a local oscillator light input waveguide, a first output waveguide array, a second output waveguide array, a first multimode interference area, a second multimode interference area and a first photonic crystal array, wherein the polarized light input waveguide is coupled to the first multimode interference area, polarized light comprises first polarization state light and second polarization state light, which are orthogonal to each other; the local oscillator light input waveguide is coupled to the first multimode interference area, the first multimode interference area is coupled to the second multimode interference area, and the first multimode interference area and the second multimode interference area are used for carrying out frequency mixing on the polarized light and the local oscillator light; the first photonic crystal array is coupled in the first multimode interference area and is used for separating the polarized light to the first polarization state light and the second polarization state light. The frequency mixer has the advantages of smaller size and capabilities of reducing the complexity of the device, improving the integration level and saving the device cost. In addition, a frequency mixing method and an optical receiver are also disclosed.

An Mach-Zehnder interferometer (500) incorporates a tunable multimode interference coupler comprising a tunable MMI coupler (504) with a tuning electrode (524) on a surface of a tunable MMI region (516) and an electrically-insulating region provided within the tunable MMI region. The MMI region is tuned in response to detection of a photocurrent measured by integrated photodetector section (510, 512). Such a tunable MZO is particularly advantageous in enabling a controlled split tio of an optical splitter.