Three-port optical circulator

Abstract

The invention discloses a three-port optical circulator. The three-port optical circulator comprises a double-optical-fiber collimator, a first beam splitting / combining crystal, a first-group polarization state converter, a light beam loop circuit device, a second-group polarization state converter, a second beam splitting / combining crystal and a single-optical-fiber collimator which are sequentially arranged on the longitudinal axis of the optical circulator. The light beam loop circuit device is formed by machining three wedge angle faces on a single birefringent crystal and serves as a crystal polarization beam splitting prism formed by three light-transmitting end faces, the optical axis of the crystal polarization beam splitting prism is located in an incident plane and forms an included angle with the longitudinal axis, and azimuth angles alpha1, alpha2 and alpha3 of the light-transmitting end faces and an azimuth angle theta of the optical axis are matched with light beam staggered-coupled angles beta of the double-optical-fiber collimator. Due to the fact that the single crystal prism is adopted as the light beam loop circuit device, a light loop device formed by combining multiple conventional optical elements is omitted, the size is decreased, assembly is facilitated, the product performance is effectively improved, and meanwhile the cost is also reduced.

Description

【Technical field】

[0001] The invention relates to an optical passive device of an optical fiber communication system, in particular to a three-port optical circulator. 【Background technique】

[0002] A three-port optical circulator is an optical passive device including three ports. A beam of light input from the first port of the circulator will be output from the second port, but the light input from the second port will not be transmitted from the first port. output, but from the third port output. Installing the optical circulator at one end of the optical fiber can separate the two beams of light that are transmitted in opposite directions in the same optical fiber to different ports at the end of the optical fiber. Therefore, the optical channel that can only transmit in one direction can be quickly and easily changed into an optical channel for bidirectional transmission, thereby doubling the optical transmission capacity. Therefore, optical circulators are widely u...

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