CN103309059A

CN103309059A - Polarization direction rotator and optical assembly thereof

Info

Publication number: CN103309059A
Application number: CN2012100698103A
Authority: CN
Inventors: 蒋艳锋; 梁韬; 何伟强; 高国祥; 张晓峰
Original assignee: Shenzhen Neo Photonic Technology Co Ltd
Current assignee: Shenzhen Neo Photonic Technology Co Ltd
Priority date: 2012-03-16
Filing date: 2012-03-16
Publication date: 2013-09-18

Abstract

The invention provides a polarization direction rotator, which comprises a Faraday optical rotary device and an optical filter, which are arranged along a forward direction optical lambda 5 incident optical axis successively, wherein an included angle theta is arranged between the optical filter and the incident optical axis. As the polarization direction rotator is only provided with the Faraday optical rotary device and the optical filter at lower price, and not provided with a polarizer and an analyzer in comparison with a traditional isolator, the backward and forward direction lights differ by 90 degrees in polarization direction.

Description

A kind of polarization direction spinner and optical assembly thereof

Technical field

The present invention relates to a kind of optic communication device, relate in particular to a kind of polarization direction spinner and optical assembly thereof.

Background technology

In two-forty, needing to stop backlight that laser light source is produced with optoisolator in the Optical Fiber Transmission of long distance disturbs, optoisolator is a kind of Passive Optical Components that allows forward light to pass through, its principle of work is based on the nonreciprocity of faraday's rotation, optoisolator as shown in Figure 1, flashlight for forward entrance, by becoming linearly polarized light behind the polarizer 1, linearly polarized light is by Faraday device 2 then, this device can be that the Faraday medium adds magnet ring, it also can be the single Faraday medium that is magnetized, Faraday device 2 makes 45 ° of the polarization direction right rotation of flashlight or anticlockwises, and just low-loss by with the analyzer 3 of polarizer placement at 45.And the linearly polarized light that backlight forms by analyzer 3 is during through Faraday device 2, also 45 ° of right rotation or anticlockwises of yawing moment, thereby make backlight polarization direction and the polarizer 1 direction quadrature, so backlight can not pass through the polarizer 1, so just block the transmission of backlight fully.But this structured light spacer structures volume is big, cost is high.

Summary of the invention

For overcoming above shortcoming, the invention provides a kind of simple in structure, the polarization direction spinner that cost is low.

For realizing above goal of the invention, the invention provides a kind of polarization direction spinner, comprising: along being provided with successively on forward light λ 5 incident light axis: a Faraday device and an optical filter, this optical filter and described incident light axis are provided with an angle theta.

Described Faraday device is the single Faraday medium that a Faraday medium adds magnet ring or is magnetized.

As another goal of the invention that the present invention uses, the present invention also provides a kind of simple in structure, cost is low, anti-backlight disturbs optical assembly.

For reaching above goal of the invention, the present invention also provides a kind of optical assembly that is provided with above-mentioned polarization direction spinner, comprising: a laser instrument and a single fiber, described polarization direction spinner is between described laser instrument and single fiber light end face.

As the another goal of the invention that the present invention uses, the present invention also provides a kind of simple in structure, cost is low, anti-backlight disturbs optical assembly.

For reaching above goal of the invention, the present invention also provides a kind of optical assembly that is provided with above-mentioned polarization direction spinner, comprise: a laser instrument, a single fiber and an optical receiver, described polarization direction spinner is between described laser instrument and single fiber light end face, and described optical receiver is positioned on the described optical filter reflection optical axis.

Because the polarization direction rotary device of said structure only has a Faraday device and the lower optical filter of a price, compare with traditional isolator and to have saved the polarizer and analyzer, can allow the polarization direction of backlight differ 90 ° with respect to forward polarisation of light direction.This polarization direction spinner is used for the laser optical assembly, because laser instrument has the insensitive characteristic of backlight of the polarization direction having been rotated 90 °, so laser instrument still can keep stable duty.On laser optical assembly basis, only increase by an optical receiver and constitute the single fiber bidirectional component, take full advantage of the optical filter reflex in the rotary device of polarization direction, single fiber is imported light reflex to optical receiver and receive the output electric signal, thereby constitute a kind of simple in structure, cost is low, transmitting terminal is stable optical assembly.

Description of drawings

Fig. 1 represents prior art optical isolator structure synoptic diagram;

Fig. 2 represents polarization direction of the present invention spinner structural representation;

Fig. 3 represents optical filter P light shown in Figure 2 and S light transmittance graph figure separately;

Fig. 4 represents to be provided with the optical assembly structural representation of polarization direction shown in Figure 2 spinner;

Fig. 5 represents to have the optical assembly structural representation of polarization direction shown in Figure 2 spinner.

Embodiment

Describe most preferred embodiment of the present invention in detail below in conjunction with accompanying drawing.

Polarization direction spinner 100 as shown in Figure 2, comprise: along being provided with successively on forward light λ 5 incident light axis: a Faraday device 10 and an optical filter 20, this optical filter 20 is provided with an angle theta with incident light axis, the occurrence of this angle theta is determined as required, Faraday device 10 can be that the Faraday medium adds magnet ring, also can be the single Faraday medium that is magnetized.For forward light λ 5, Faraday device 10 makes 45 ° of the right rotation of incident light polarization direction or anticlockwises.When the polarization of incident light direction of Faraday device 10 and the plane of incidence angle at 45 of optical filter 20, this angle can be also can be counterclockwise clockwise, its polarization direction right rotations or anticlockwise are 45 ° behind the incident light process Faraday device 10, thereby become P light or the S light of optical filter.As long as the wavelength value of the forward light λ 5 of optical filter 20 is between λ 1～λ 2, most P light or S light pass through as can be known by the polarization selectivity characteristic of optical filter 20, its correspondence be the reflection of most S light or P light, incident light λ 5 just can remain unchanged by optical filter 20 and polarization direction.Equally, for the wavelength value of the backlight λ 5 of optical filter 20 also between λ 1～λ 2, its polarization direction also is any direction, but the P light or the S light that have only the polarization direction to be parallel to the big direction of optical filter 20 transmissivities just can most ofly pass through optical filter 20, backlight λ 5 after the transmission understands 45 ° of right rotation or anticlockwises equally through Faraday devices 10 rear polarizer directions, and postrotational backlight λ 5 polarization directions and incident light λ 5 polarization directions differ 90 °.By as shown in Figure 3, the P light of optical filter 20 and S light is transmittance graph figure separately, λ 1 expression satisfy P light or S light transmission more than or equal to 95% or other number percent simultaneously S light or P light transmission smaller or equal to 0.1% or the minimum wavelength value of other number percent; λ 2 expression satisfy P light or S light transmission more than or equal to 95% or other number percent simultaneously S light or P light transmission smaller or equal to 0.1% or the maximum wavelength value of other number percent.λ 3, λ 4 expression P light and S optical transmission rate be all smaller or equal to 0.1% or the flashlight of the wavelength coverage of other number percent, the wavelength value light signal of λ 6 between λ 3～λ 4.The size of λ 1, λ 2, λ 3, λ 4 is relevant with the transmissivity size of optical filter 20 defineds.

Be provided with optical assembly---the laser assembly of polarization direction shown in Figure 2 spinner 100 as shown in Figure 4, comprise: a laser instrument 200 and a single fiber 300, one polarization direction spinners 100 are between laser instrument 200 and single fiber 300 smooth end faces.The forward light λ 5 of laser instrument 200 emissions is by behind the polarization direction spinner 100, reenter the light end face output that is incident upon single fiber 300, and the polarization direction of λ 5 backlights that single fiber 300 smooth end face reflections are returned differs 90 ° according to the polarization direction that is polarized direction spinner 100 rotation backs and forward light λ 5 described above, and laser instrument 200 is insensitive to this polarization state backlight, so do not influence the job stability of laser instrument.

Be provided with the optical assembly of polarization direction shown in Figure 2 spinner 100 as shown in Figure 5---single fiber transmitted in both directions optical assembly, comprise: a laser instrument 200, a single fiber 300 and an optical receiver 400, one polarization direction spinner 100 is between laser instrument 200 and single fiber 300 smooth end faces, and optical receiver 400 is positioned on optical filter 20 reflection optical axis of polarization direction spinner 100.At first the forward light λ 5 of laser instrument 200 emission successively is incident to single fiber 300 smooth end faces outputs behind the Faraday device 10 by polarization direction spinner 100 and the optical filter 20, and its principle of work and Fig. 4 are identical, do not repeat at this.And from another road light signal λ 6 backlights opposite with forward light λ 5 directions of the far-end incident of single fiber 300, as shown in Figure 3, the wavelength value of λ 6 between λ 3～λ 4, can not see through the optical filter 20 of polarization direction spinner 100, reflexing to optical receiver 400 through this optical filter changes electric signal output.This structure single fiber transmitted in both directions optical assembly utilizes polarization direction of the present invention spinner to replace the higher isolator of common price, a shared optical filter is provided again, its performance satisfies the high-stability requirement of the passive net optical line terminal of high speed fully, but has reduced cost, and structure is also simplified more.

Claims

1. a polarization direction spinner (100) is characterized in that, comprising: along being provided with successively on forward light λ 5 incident light axis: a Faraday device (10) and an optical filter (20), this optical filter (20) is provided with an angle theta with described incident light axis.

2. polarization direction spinner according to claim 1 (100) is characterized in that, described Faraday device (10) is the single Faraday medium that a Faraday medium adds magnet ring or is magnetized.

3. one kind is provided with the optical assembly of polarization direction spinner (100) according to claim 1, it is characterized in that, comprise: a laser instrument (200) and a single fiber (300), described polarization direction spinner (100) are positioned between described laser instrument (200) and single fiber (300) the light end face.

4. one kind is provided with the optical assembly of polarization direction spinner (100) according to claim 1, it is characterized in that, comprise: a laser instrument (200), a single fiber (300) and an optical receiver (400), described polarization direction spinner (100) is positioned between described laser instrument (200) and single fiber (300) the light end face, and described optical receiver (400) is positioned on described optical filter (20) reflection optical axis.