Magneto-optical variable optical attenuator

Abstract

The invention discloses a magneto-optical variable optical attenuator, which sequentially comprises an input collimator, a first birefringent crystal, a first half-wave plate, a first Faraday rotatingplate, a second Faraday rotating plate, a polarizing film, a second half-wave plate, a second birefringent crystal and an output end collimator in the propagation direction of light, wherein the periphery of the first Faraday rotating plate and the periphery of the second Faraday rotating plate are sleeved with a variable magnetic field applying mechanism; and a magnetic field direction of the variable magnetic field applying mechanism is parallel to the horizontal axis. According to the magneto-optical variable optical attenuator, the polarization state of light passing through the Faraday rotating plates is changed by changing the magnetic field intensity passing through the Faraday rotating plates, so that the polarization state of light passing through a polarizing film serving as a polarization analyzer is changed. The polarizer absorbs light that is not parallel to the polarization direction thereof, thus the function of adjusting light intensity attenuation is realized. The magneto-optical variable optical attenuator is simple in structure, easy to assemble, convenient to control, high in working reliability, low in product cost and less in stray light.

Description

technical field [0001] The invention belongs to the technical field of optical devices, and in particular relates to a magneto-optical adjustable optical attenuator. Background technique [0002] In the optical fiber communication system, there are many scenarios that need to reduce the power of the optical signal, such as: the optical receiver is very sensitive to the overload of the optical power, the input power must be controlled within the input range of the optical receiver to prevent its saturation; the front of the optical amplifier The balance between the input power of different channels can prevent the input power of one or some channels from being too large and the gain saturation of the optical amplifier. [0003] The optical attenuator can attenuate the expected power of the optical signal according to the user's requirements. Optical attenuators include mechanical optical attenuators, magneto-optical adjustable optical attenuators, MEMS optical attenuators, t...

AI Technical Summary

Problems solved by technology

This implementation is prone to increase the stray light in the optical path, causing unnecessary return loss and crosstalk

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