CN201569820U

CN201569820U - Optical isolator

Info

Publication number: CN201569820U
Application number: CN2009201338787U
Authority: CN
Inventors: 谢红; 聂淼; 李益民
Original assignee: O Net Communications Shenzhen Ltd
Current assignee: O Net Technologies Shenzhen Group Co Ltd
Priority date: 2009-07-21
Filing date: 2009-07-21
Publication date: 2010-09-01
Anticipated expiration: 2019-07-21

Abstract

The utility model discloses an optical isolator, which relates to the field of optical communication and comprises a Faraday rotator and a 45-degree polaroid. The optical isolator is characterized in that: the Faraday rotator rotates the polarization state of incident polarized light by 45 degrees, the transmission axis of the 45-degree polaroid makes the included angle of 45 degrees with the horizontal direction, and the 45-degree polaroid is arranged behind the Faraday rotator. Compared with the prior art, the utility model has the advantages of small structure, low cost and the like.

Description

A kind of optoisolator

Technical field

The utility model relates to the device in a kind of optical communication field, particularly a kind of optoisolator spare.

Background technology

Optoisolator is the laser instrument that is applied to optical communication the earliest, and it mainly acts on is that the light of forward transmitted is passed through, and the light of reverse transfer is isolated.Isolator is divided into optical-fiber type and free space type two big classes as if the environment by its use; Isolator also can be by polarization relevant and polarization irrelevant classify, all have for two kinds at line style and free space type to comprise that the polarization relationship type isolator of general free space type is used more, mainly is used in the encapsulation of LASER Light Source.

Wherein, the structure of isolator is: one 0 ° of polarizers, 45 ° of Faraday rotators and another 45 ° of polarizers, its ultimate principle is: during forward transmitted, light enters 45 ° of polarizers from the laser instrument emitted light beams after by 0 ° of polarizer and 45 ° of Faraday rotators, because the light transmission shaft of 45 ° of polarizers just is 45 °, 45 ° of polarized lights receive by collimating apparatus or optical fiber; Because the effect of the irreversible rotation of Faraday rotator makes by polarization state direction behind the Faraday rotator vertically with 0 ° of polarizer optical axis, so during reverse transfer, light can not enter collimating apparatus, plays the effect to the backlight isolation when the light reverse transfer.This structure exists volume big, is not easy to be integrated in the optical transceiver module defectives such as cost height.

Summary of the invention

A kind of optoisolator of the utility model, have simple in structure, the advantage that cost is low.

To achieve these goals, a kind of optoisolator of the utility model, form by Faraday rotator and 45 ° of polaroids, it is characterized in that: Faraday rotator rotates 45 ° with the polarization state of incident beam, the light transmission shaft of 45 ° of polaroids and horizontal direction angle at 45, described 45 ° of polaroids place after Faraday rotator.

Wherein, preferred version is: comprise that also a quarter-wave plate places after 45 ° of polaroids, its optical axis and 45 ° of polaroid light transmission shafts are at 45.

Wherein, preferred version is: described Faraday rotator, 45 ° of polaroids and quarter-wave plate form one by chemical assistant reaction gummed or glue bond mode.

Because it is adopted above-mentioned optoisolator, not only simple in structure but also cost is low.

Description of drawings

Engaging accompanying drawing below further specifies embodiments of the invention:

Fig. 1 is the structure principle chart of first embodiment of the utility model optoisolator.

Fig. 2 is the structure principle chart of second embodiment of the utility model optoisolator.

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing.

As shown in Figure 1, this isolator 10 comprises that a Faraday rotator 11 is coupled on one 45 ° of polaroids 12, its principle of work is, the light beam L1 that laser instrument 16 emits, has polarization state 101, this light beam L1 is through behind the Faraday rotator 11, and light beam L1 has polarization state 102, and this Faraday rotator 14 is set to 45 ° of polarization state rotations.

Wherein, Faraday rotator 11 can be from the magnetic material, or non-from the magnetic material, if be non-, also comprise an outside magnetic tube 111 from the magnetic material, described light beam L1 has rotated 45 ° through Faraday rotator 11 polarization states, it has polarization state 102, and by 45 ° polarizer 12, light beam L1 only is 45 ° light beam L1 by polarization state like this behind the light beam L1, this light beam has polarization state 103, and then collimated device or optical fiber 13 receiving beams receive.

The light beam L2 that returns like this can be any polarization state, has polarization state 104, the polarizing beam L2 that has among the light beam L2 through 45 ° passes through described 45 ° of polaroids 12, light beam L2 has polarization state 105, light beam L2 is after by 45 ° of Faraday rotator 11 rotations, light beam L2 has polarization state 106, return the polarization state of light direction like this and become 90 ° of direction return laser light devices with optical axis, because the light beam of this vertical polarization attitude does not impact laser instrument, back light does not cause performance impact to laser instrument like this, thereby has played buffer action.

Fig. 2 is the structure principle chart of second embodiment of the utility model optoisolator, as shown in Figure 2: present embodiment optoisolator 20 comprises Faraday rotator 21, one 45 ° of polaroids 22 and a quarter-wave plate 23, described Faraday rotator 21, one 45 ° of polaroids 22 and a quarter-wave plate 23 are coupled as one, its principle of work is: the light beam L1 that emits from laser instrument 26, it has polarization state 201, through Faraday rotator 21, after this light beam L1 rotates through Faraday rotator 21, light beam L1 has polarization state 202, and this Faraday rotator 21 is set to 45 ° of polarization state rotations.

Wherein, Faraday rotator 21 can be from the magnetic material, or it is non-from the magnetic material, if be non-from the magnetic material, also comprise an outside magnetic tube 211, described light beam L1 has rotated 45 ° through Faraday rotator 21 polarization states, it has polarization state 202, and the light beam L1 with polarization state 202 passes through 45 ° polarizer 22, and light beam L1 only is 45 ° light beam by polarization state like this, this light beam L1 has polarization state 203, the light beam L2 that then has polarization state 203 is via quarter-wave plate 23, and is by the light beam L1 of wave plate 23, (left-handed from linearly polarized light, or dextrorotation) change circularly polarized light beam L2 into, have polarization state 204 collimated devices in back or optical fiber 23 and receive.

The light beam L2 that returns like this can be circular polarization state, has polarization state 205, the sense of rotation of the circularly polarized light of light beam L2 is than forward (the left-handed change dextrorotation that changes, or dextrorotation becomes left-handed), after passing through quarter-wave plate 23 again, 90 ° deflection has taken place than the forward transmission in light beam L3, light beam L2 has polarization state 206, light beam L3 is through described 45 ° of polaroids 22, the light beam L2 that passes through has polarization state 207, light beam L3 is after by 45 ° of Faraday rotator 21 rotations, light beam L3 has polarization state 208, returns the polarization state of light direction like this and becomes 90 ° polarization state direction return laser light device than the forward transmission direction, because the light beam of this vertical polarization attitude does not impact laser instrument, back light does not cause performance impact to laser instrument like this, thereby has played buffer action.

The utility model has the advantage of: owing to adopted above-mentioned optoisolator, not only simple in structure but also cost is low.

Claims

1. optoisolator, form by Faraday rotator and 45 ° of polaroids, it is characterized in that: Faraday rotator rotates 45 ° with the polarization state of incident beam, the light transmission shaft of 45 ° of polaroids and horizontal direction angle at 45, and described 45 ° of polaroids place after Faraday rotator.

2. optoisolator according to claim 1 is characterized in that: comprise that also a quarter-wave plate places after 45 ° of polaroids, its optical axis and 45 ° of polaroid light transmission shafts are at 45.

3. optoisolator according to claim 1 and 2 is characterized in that: described Faraday rotator, 45 ° of polaroids and quarter-wave plate form one by chemical assistant reaction gummed or glue bond mode.