Reverse isolation polarized light beam combiner

Abstract

The invention discloses a reverse isolation polarized light beam combiner. The reverse isolation polarized light beam combiner comprises a double-fiber collimator, a magnetic ring, a first wedge-shaped double-refraction crystal, a Faraday rotation sheet, a second wedge-shaped double-refraction crystal and a single-fiber collimator, wherein the first wedge-shaped double-refraction crystal, the Faraday rotation sheet and the second wedge-shaped double-refraction crystal are arranged in the magnetic ring from back to front in turn along the direction of a light path; the double-fiber collimator, the magnetic ring and the single-fiber collimator are arranged in turn from back to front along the direction of the light path; a 45-degree included angle is formed between a main plane of the first wedge-shaped double-refraction crystal and a main plane of the second wedge-shaped double-refraction crystal; and the rotation angle of the polarization direction to linearly polarized light by the Faraday rotation sheet is 45 degrees. The reverse isolation polarized light beam combiner has a function of reverse isolation; and by using the reverse isolation polarized light beam combiner, the working stability of a light source can be improved, so that an amplifier has better gain stability. Meanwhile, the reverse isolation polarized light beam combiner has the advantages of small volume and low cost.

Description

technical field [0001] The invention relates to an optical device used in the field of optical fiber communication, in particular to a reverse-isolated polarization beam combiner which integrates two functions of a polarization beam combiner and an optical isolator. Background technique [0002] Erbium-doped fiber amplifier is the key equipment in the long-distance optical fiber communication system. It is used to compensate the optical power loss on the transmission line, but its amplified wavelength only covers the range of about 80nm from the C-band to the L-band. Raman fiber amplifiers can be used for amplification, so Raman fiber amplifiers are an important supplement to erbium-doped fiber amplifiers. [0003] The Raman fiber amplifier uses the stimulated Raman scattering effect in the fiber to perform optical amplification. The wavelength of the amplified signal light depends on the wavelength of the pump light. The selection of the amplification wavelength is relative...

AI Technical Summary

Problems solved by technology

However, the polarization beam combiner does not have the function of reverse isolation

If the reflected light on the optical fiber line returns to the pump light source, it will interfere with the working stability of the light source, thereby affecting the gain stability of the amplifier, so an optical isolator is needed to isolate the reflected light on the line

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