High-efficiency low-loss all-fiber fusion mode selection coupler

Abstract

The invention discloses a high-efficiency low-loss all-fiber fusion mode selection coupler comprising a less-mode fiber and a single-mode fiber with a coating layer respectively peeled off; the single-mode fiber is specially made; the refractive index of the fiber core of the single mode fiber under a specific wavelength is smaller than the quality of the fiber core refractive index of the less-mode fiber under the same wavelength; the high purity high order mode in the less-mode fiber can be excited without pre-tapering the single-mode fiber or less-mode fiber; a model switching function anda mode separating function are provided. The selection coupler can pack through a packing material. The single-mode fiber and less-mode fiber employ the all-fiber fusion coupling mode, the structure is compact, and the formed mode selection coupler is high in coupling efficiency, high in polarization purity, small in insert loss, and simple in making process.

Description

technical field [0001] The invention belongs to the technical field of optical fiber couplers, and in particular relates to a high-efficiency and low-loss all-fiber fusion mode selective coupler. Background technique [0002] At present, the optical fiber used in the communication field is a single-mode optical fiber, but the single-mode optical fiber that can only transmit one mode is rapidly approaching the limit of its transmission capacity. To solve this capacity limit, various methods including wavelength division multiplexing (WDM) and polarization division multiplexing (PDM) have been proposed. In recent years, mode division multiplexing (MDM) has become the focus of improving the data carrying capacity of optical fibers. The optical fiber used in this method is a few-mode optical fiber capable of transmitting several high-order spatial modes, rather than a single-mode optical fiber limited to one spatial mode. One of the most important issues in a mode-division mult...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the disadvantages of the mode selective coupler in the prior art, such as low coupling efficiency, large insertion loss and complicated process, the present invention provides a high-efficiency, low-loss all-fiber fusion mode selective coupler, and all components of the mode selective coupler adopt All-fiber coupling mode, compact structure, not affected by external factors, can work continuously and stably, and the mode selection coupler has high coupling efficiency, low insertion loss and simple process

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