Mode multiplexer/demultiplexer, mode demultiplexing method and mode multiplexing method

Abstract

A mode multiplexer / demultiplexer, a mode demultiplexing method and a mode multiplexing method relate to the technical field of optical communication devices. The mode multiplexer / demultiplexer comprises a multimode interference waveguide which is asymmetric and variable in width, a multimode waveguide which is connected to the left side of the multimode interference waveguide, and two transmissionwaveguides which are connected to the right side of the multimode interference waveguide, wherein a first port is formed in the left end of the multimode waveguide, and a second port is formed in thesingle-mode waveguide at the right end of each transmission waveguide. The mode multiplexer / demultiplexer has the advantages that internal interference points can be adjusted by adjusting the shape of the multimode interference waveguide, mode multiplexing and demultiplexing are achieved, the structural process tolerance is large, the size is small, no fine waveguide structure exists, the machining precision requirement is not high, and the manufacturing cost is low.

Description

technical field [0001] The invention relates to the technical field of optical communication devices, in particular to a mode multiplexing and demultiplexing device, a mode demultiplexing method and a mode multiplexing method. Background technique [0002] Mode multiplexing / demultiplexing is an important device in applications such as optical communication and optical signal processing. Its function is mainly mode multiplexing or demultiplexing, and can be used in mode multiplexing or polarization multiplexing. There are two main types of mode multiplexers / demultiplexers currently in use: directional couplers or asymmetrical Y-branches. [0003] For the directional coupler, there are two device structures, one is the ordinary straight waveguide directional coupler, in this structure the two waveguides of the directional coupler must strictly meet the phase matching conditions, it is very sensitive to the process, and the process tolerance is low. The second structure is a d...

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Problems solved by technology

The second structure is a directional coupler with a trapezoidal waveguide structure. Although this structure does not require high process precision, it needs to be very long and relatively large in order to obtain better performance.

[0004] For the asymmetric Y branch, it also uses the coupled mode theory. Although this kind of device can be made very small, there are small slits in the Y branch, which have a great impact on the performance of the device, so it is necessary to obtain a good The performance of the device must be made with very high-precision equipment, and the cost is very high

[0005] The existing mode multiplexer / demultiplexer has the problems of small process tolerance, large size, high processing precision and high processing cost

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