Optical mixer

Abstract

The invention discloses an optical mixer, and relates to the field of coherent optical communication. The optical mixer comprises an optical cross connector, multimode bend waveguide, two input beam splitters and two output beam splitters; the two input beam splitters are used for conducting beam splitting on signal light and local oscillator light and then transmitting the signal light and the local oscillator light to the optical cross connector through the multimode bend waveguide; the optical cross connector is used for conducting cross transmission on the output light of the two input beam splitters and then transmitting the output light to the two output beam splitters through the multimode bend waveguide; the multimode bend waveguide has the effect that base mode light enters the multimode bend waveguide and then generates multimode interference, and the base mode light is emitted at an outlet of the multimode bend waveguide; and the two output beam splitters are used for receiving the light which is emitted by the optical cross connector and transmitted by the multimode bend waveguide, and outputting the base mode light. The yield of the optical mixer can be increased whilethe bandwidth of the optical mixer is increased and the insertion loss of the optical mixer is lowered.

Description

technical field [0001] The invention relates to the field of coherent optical communication, in particular to an optical mixer. Background technique [0002] The optical mixer is a crucial device in coherent optical communication. It is used for the demodulation of coherent signals. The phase error of each channel outlet of the optical mixer must be very small. [0003] There are generally two types of optical mixers currently in use: [0004] 1. An optical mixer based on a 4×4 (4 input terminals and 4 output terminals) or 2×4 (2 input terminals and 4 output terminals) multimode interferometer, when the optical mixer is used , due to the characteristics of the 4×4 or 2×4 multimode interferometer itself, the bandwidth of the optical mixer will be small and the insertion loss will be large. [0005] 2. Optical mixers based on optical crossover and 1×2 and 2×2 beam splitters, the optical components of the optical mixer are connected by single-mode waveguides; however, the eff...

AI Technical Summary

Problems solved by technology

[0005] 2. Optical mixers based on optical crossover and 1×2 and 2×2 beam splitters, the optical components of the optical mixer are connected by single-mode waveguides; however, the effective refractive index of single-mode waveguides affects the waveguide Width changes are very sensitive, and process errors cause unavoidable fluctuations in the actual width of the waveguide, which eventually leads to a large fluctuation in the phase error of the optical mixer based on the single-mode waveguide, which in turn makes the yield of the optical mixer lower.

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