CN1393724A

CN1393724A - Light isolator

Info

Publication number: CN1393724A
Application number: CN 01114861
Authority: CN
Inventors: 李俊佑; 余泰成; 邓兆展; 陈建呈
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2001-06-21
Filing date: 2001-06-21
Publication date: 2003-01-29

Abstract

A light isoaltor is composed of two optical fibre collimators, sleeve tube, an isolating center and an external metal tube. The isoalting center consists of two polarizers, a polarizing rotary crystal and a magnetic ring whose length is slightly less than or equal to the total length of the two polarizers and the rotary crystal. Regulating the relative position between the assembly of sleeve tube, magnetic ring and a collimator and the another collimator in external metal tube can obtain the optimal insertion loss and isolation degree.

Description

Optoisolator

The invention relates to a kind of optoisolator, especially a kind of magnet ring length is shorter, low cost of manufacture and can clean the optoisolator of quarantine center's plane of crystal in assembling process in advance.

In optical communication system, flashlight can be through many different optical interface in transmission course, reflection in various degree all can appear in its each optical interface of process, and the return light may that reflection is produced may be returned light source along original optical path, and then cause the light source works instability, produce problems such as frequency drift, signal attenuation variation, thereby influence overall optical communication system operate as normal.For fear of return light may devices such as light source are exerted an influence, must suppress return light may, to guarantee the work quality of optical communication system with optoisolator.Optoisolator is a kind of forward transmission light to be had than low insertion loss, and reverse transfer light is had the nonreciprocity optical passive component of very high attenuation, in order to suppress return light may in the optical communication system to adverse effect that light source caused.

As shown in Figure 1, existing optoisolator 1 comprises first, second fiber optic collimator device 10, a quarantine center 30 and metal outer pipe 40, this fiber optic collimator device 10 is made up of with the contact pin 14 of fixed fiber 15 0.25 pitch GRIN Lens 13 (0.23 pitches that adopt in the reality) more, fiber optic collimator device 10 is a directional light with the Beam Transformation of transmitting in the optical fiber, to improve the coupling efficiency between optical device.This quarantine center 30 places first, between the second fiber optic collimator device 10, comprise first polarizer 33, polarization rotating crystal 32, second polarizer 31 and magnet ring 34, wherein

polarizer

31,33 can be divided into the light beam by it mutually perpendicular o light in polarization direction and e light, this polarization rotating crystal 32 is to utilize the Faraday effect of magneto-optical crystal, promptly the polarization rotating crystal of being made by magneto-optical crystal is under the action of a magnetic field, the vibration plane of the polarized light by this polarization rotating crystal 32 is rotated, the optically-active angle of existing optoisolator polarization rotating crystal is 45 degree, becomes miter angle and the optical axis of this second polarizer 31 and the optical axis of first polarizer 33 are interlaced.When the light signal forward transmitted, light signal is through the first fiber optic collimator device, 10 collimations, after entering first polarizer 33, light beam is divided into o light and e light, its polarization direction is orthogonal, when they through 45 the degree polarization rotating crystal 32 time, the vibration plane of outgoing o light and e light is separately to same direction rotation 45 degree, because the crystallographic axis of second polarizer 31 just in time is 45 degree with respect to first polarizer 33, so o light and e light are converged to together by 31 refractions of second polarizer, and be coupled in the output optical fibre 15 through the GRIN Lens 13 of the second fiber optic collimator device 10, thereby forward light with minimum loss by optoisolator 1.Because the nonreciprocity of Faraday effect, when the light beam reverse transfer, at first through second polarizer 31, be divided into plane of polarization becomes 45 degree with the first polarizer crystallographic axis o light and e light, when this two polarized light through 45 the degree polarization rotating crystal 32 time, its vibration plane is still towards direction rotation 45 degree consistent with forward light sense of rotation, two separating light beam o light of retroeflection and e light have carried out mutual conversion each other with respect to first polarizer, 33 its character thus, promptly the o light from 31 outgoing of second polarizer becomes the light for e with respect to first polarizer, and become light with respect to first polarizer 33 for o from the e light of second polarizer, 31 outgoing, the difference of character such as the rate of penetrating of shaking owing to o light e light makes two separating light beams no longer converge along original optical path and enters input optical fibre, further be separated into than wide-angle by first polarizer 33 on the contrary, and can not be coupled in first input optical fibre 15, and then reach the purpose of reverse isolation.

The quarantine center 30 of existing optoisolator 1 places between this two fiber optic collimators device 10.This fiber optic collimator device 10 is standard fiber collimating apparatuss, the contact pin 14, a GRIN Lens 13, a sleeve pipe 12 and the metal inner pipe 11 that comprise a band optical fiber 15, this contact pin 14 and GRIN Lens 13 all are fixed in this sleeve pipe 12, and the some of GRIN Lens 13 protrudes out sleeve pipe 12, and this metal inner pipe 11 is set in outside this sleeve pipe 12; This quarantine center 30 comprises first polarizer 31, polarization rotating crystal 32, second polarizer 33 and magnet ring 34, and wherein this first polarizer 31, polarization rotating crystal 32 and second polarizer 33 place magnet ring 34 and fixing successively.During assembling, protrude out the part 131 coating glue of sleeve pipe 12 in the GRIN Lens 13 of a fiber optic collimator device 10, magnet ring 34 is entangled this gluing part, and this fiber optic collimator device 10 is fixed together with quarantine center 30, then, this combination and another fiber optic collimator device are placed metal outer pipe 40, adjust both relative positions, fix when best simultaneously when inserting loss and isolation.But, for this fiber optic collimator device 10 is connected with quarantine center 30, and each assembly has relative accurate localization, this magnet ring 34 needs long length to regulate degree of freedom to make things convenient for socket GRIN Lens 13 and to increase, so need long magnet ring will improve the cost of overall optical isolator, and the long not easy to clean so that insertion loss that increases optoisolator of magnet ring 34 during assembling.Simultaneously, use viscose to be connected in the above described manner can to make in the cover termination process to produce the glue that overflows, pollute lens and the surface of the polarizer that links to each other and influence the insertion loss of whole isolated device.

The object of the invention is to provide a kind of magnet ring length shorter, the optoisolator of convenient cleaning quarantine center's plane of crystal of row again and low cost of manufacture in the assembling process.

Technical characterictic of the present invention is: it mainly comprises two fiber optic collimator devices, a sleeve, a quarantine center and a metal outer pipe.This jacket casing is connected to the wherein end of a fiber optic collimator device; Quarantine center comprises first polarizer, polarization rotating crystal, second polarizer and magnet ring, and the total length of this magnet ring is slightly less than or equals the summation of two polarizers and polarization rotating crystal length, to shorten the length of magnet ring.During assembling, this magnet ring is pasted on the end face of sleeve or places sleeve, and this combination and another fiber optic collimator device are placed metal outer pipe, adjusts both relativenesses, fixes when best simultaneously when inserting loss and isolation.The magnet ring length of this optoisolator reduces, and can go before encapsulation again and clean quarantine center, thereby can reduce to insert loss, and reduce the manufacturing cost of overall optical isolator, and this design simultaneously can reduce the generation of bad excessive glue.

Compare with existing optics combination, the present invention has following remarkable advantage: because of magnet ring length reduces, can clean quarantine center once more before the encapsulation, thereby can reduce to insert loss, and will reduce the manufacturing cost of overall optical isolator, this design simultaneously can reduce bad excessive glue and produce.

Below in conjunction with accompanying drawing embodiments of the invention are elaborated:

Fig. 1 is the cross section view of existing optoisolator.

Fig. 2 is the cross section view of first embodiment of the invention optoisolator.

Fig. 3 is the cross section view of second embodiment of the invention optoisolator.

See also Fig. 2, the cross section view of optoisolator first embodiment of the present invention, this optoisolator 2 comprise two fiber optic collimator devices 10, a sleeve 8, a quarantine center 60 and a metal outer pipe 40.

This two fiber optic collimators device 10 includes a contact pin 14, a GRIN Lens 13, a sleeve pipe 12 and a metal inner pipe 11.Wherein this contact pin 14 comprises first end 18, second end 19 and an endoporus 16, this endoporus 16 is provided with a chamfering 181 near first end, 18 places and inserts in the endoporus 16 to make things convenient for optical fiber 15, and the end face of this optical fiber 15 is flushed with second end 19, this second end 19 is worn into certain angle, and is coated with anti-reflective film in this end face 19.This sleeve pipe 12 is roughly a hollow tube; can be made by glass material, in order to suit fixedly GRIN Lens 13 and contact pin 14, the some of this GRIN Lens 13 protrudes out for outside the sleeve pipe 12; this metal inner pipe 11 is roughly isometric with sleeve pipe 12, is used to overlap tubing 12 with protection assembly wherein.

This sleeve 8 is that one of them GRIN Lens 13 of socket two fiber optic collimator devices protrudes out for the outer part of sleeve pipe 12, and sleeve 8 is protruded out for outside the GRIN Lens 13, for strengthening being connected of sleeve 8 and fiber optic collimator device 10, available viscose glue is pasted on sleeve 8 on sleeve pipe 12 end faces of this fiber optic collimator device 10.

This quarantine center 60 places between the two fiber optic collimator devices 10, it comprises first polarizer 61, polarization rotating crystal 62, second polarizer 63 and magnet ring 64, this first polarizer 61, polarization rotating crystal 62 and second polarizer 63 are to place magnet ring 64 successively, wherein this first polarizer 61 and second polarizer 63 are all birefringece crystal, interlaced one-tenth 45 degree of the optical axis of two birefringece crystals when placing magnet ring 64, this polarization rotating crystal 62 is the Faraday crystal, and its optically-active angle is roughly 45 degree.The total length of this magnet ring 64 can be slightly less than or equal the summation of two

polarizers

61,63 and polarization rotating crystal 62 length, to shorten the length of magnet ring 64.During assembling, the magnet ring 64 that is set with first polarizer 61, polarization rotating crystal 62 and second polarizer 63 is sticked in the end face of sleeve 8, this moment can be with regard to

quarantine center

60 and 10 preset in advance of fiber optic collimator device, to obtain best isolation effect.Then, again this combination and another fiber optic collimator device 10 are placed metal outer pipe 40, adjust both relative positions, when insert loss and isolation when best simultaneously encapsulation be fixed into optoisolator.Because magnet ring 64 length of this optoisolator reduce, therefore can go again before the encapsulation and clean quarantine center's 60 planes of crystal, reducing to insert loss, and reduction optoisolator manufacturing cost.Simultaneously, magnet ring 64 is glued at sleeve 8 end faces, and the glue that can prevent to overflow produces, and reduces defective products.

See also Fig. 3, it is the cross section view of optoisolator second embodiment of the present invention, compare with the optoisolator 2 of first embodiment, the sleeve 8 ' of this optoisolator 3 is longer than the sleeve 8 of optoisolator 2, and this quarantine center's 60 ' size is less, and this quarantine center 60 ' is that suit is fixed in the sleeve 8 '.

Claims

1. an optoisolator comprises two fiber optic collimator devices and a quarantine center, and wherein each fiber optic collimator device comprises a contact pin, lens and a sleeve pipe, and this sleeve pipe is that suit is fixed these lens and this contact pin, and the part of lens protrudes out outside the sleeve pipe; This quarantine center places between the two fiber optic collimator devices, and it comprises first polarizer, polarization rotating crystal, second polarizer and magnet ring, and this first polarizer, polarization rotating crystal and second polarizer place magnet ring successively.It is characterized in that this optoisolator also comprises a sleeve, the lens of this jacket casing fiber optic collimator device located therein protrude out the outer part of sleeve pipe, and the magnet ring that is set with first polarizer, polarization rotating crystal and second polarizer is pasted on this sleeve end face.

2. optoisolator as claimed in claim 1 is characterized in that contact pin one end face of two fiber optic collimator devices is worn into a special angle, and is coated with anti-reflective film in this end face.

3. optoisolator as claimed in claim 1 or 2, the lens that it is characterized in that this two fiber optic collimators device are GRIN Lens.

4. optoisolator as claimed in claim 1 or 2 is characterized in that the sleeve pipe of this two fiber optic collimators device is made by glass material, is roughly a hollow tube.

5. optoisolator as claimed in claim 1 is characterized in that this sleeve made by glass material.

6. optoisolator as claimed in claim 1 is characterized in that first polarizer and second polarizer can be birefringece crystal, and the polarization rotating crystal is a Faraday rotator.

7. optoisolator as claimed in claim 1 is characterized in that the total length of this quarantine center's magnet ring can be slightly less than or equal two polarizers and polarization rotating crystal length summation.

8. an optoisolator comprises two fiber optic collimator devices and a quarantine center, and wherein each fiber optic collimator device comprises a contact pin, lens and a sleeve pipe, and this sleeve pipe is that suit is fixed these lens and this contact pin, and the part of lens protrudes out outside the sleeve pipe; This quarantine center places between the two fiber optic collimator devices, and it comprises first polarizer, polarization rotating crystal, second polarizer and magnet ring, and this first polarizer, polarization rotating crystal and second polarizer place magnet ring successively.It is characterized in that this optoisolator also comprises a sleeve, the lens of this jacket casing fiber optic collimator device located therein protrude out the outer part of sleeve pipe, and the magnet ring that is set with first polarizer, polarization rotating crystal and second polarizer is installed in this sleeve.

9. optoisolator as claimed in claim 8 is characterized in that contact pin one end face of two fiber optic collimator devices is worn into a special angle, and is coated with anti-reflective film in this end face.

10. optoisolator as claimed in claim 8 or 9, the lens that it is characterized in that this two fiber optic collimators device are GRIN Lens.

11. optoisolator is characterized in that the sleeve pipe of this two fiber optic collimators device is made by glass material as claimed in claim 8 or 9, is roughly a hollow tube.

12. optoisolator as claimed in claim 8 is characterized in that this sleeve made by glass material.

13. optoisolator as claimed in claim 8 is characterized in that first polarizer and second polarizer can be birefringece crystal, the polarization rotating crystal is a Faraday rotator.

14. optoisolator as claimed in claim 8 is characterized in that the total length of this quarantine center's magnet ring can be slightly less than or equal two polarizers and polarization rotating crystal length summation.