CN2482105Y

CN2482105Y - Circulator

Info

Publication number: CN2482105Y
Application number: CN 01238200
Authority: CN
Inventors: 吴砺; 凌吉武; 刘淑云; 詹翠莲; 陈铭星
Original assignee: Casix Inc
Current assignee: Casix Inc
Priority date: 2001-06-07
Filing date: 2001-06-07
Publication date: 2002-03-13
Anticipated expiration: 2011-06-07

Abstract

The utility model discloses a novel circulator which consists of dual fiber collimators (3, 4), single fiber collimators (15, 16), and a three-port circulator with the close structure formed by the three optical function combinations A, B, and C, namely, a double prism, a Wollaston prism, a one seconds wave plate, and a faraday rotary plate in sequence arranged between the dual fiber collimators (3, 4) and the single fiber collimators (15, 16). Because the utility model adopts the dual fiber collimators, the volume of the whole apparatus already realizes miniaturization, the utility model has another characteristic that the Wollaston prism and an optical prism are totally adopted, compared with a large double refraction crystal adopted by a traditional circulator, the cost can be greatly reduced, thereby having very great practical value and potential.

Description

A kind of novel circulator

This novel optical circulator field that relates to optical-fibre communications especially refers to a kind of tight type, optical circulator cheaply.

In optical circulator, the structure of pursuing tight type, small size is the main trend of various designs recent years.Most typical structure is a patent, and its structure light path principle as shown in Figure 1.

This novel typical feature is to have adopted wollaston prism and double-fiber collimator, with 1 in traditional circulator design, 2,3 passage independent separate states merge and utilize identical several crystal jointly, materials such as crystal have so not only been saved, and two collimating apparatuss of original two ports are merged into same collimating apparatus, thus reduced device volume greatly, realized the tight miniaturization of circulator.Its shortcoming is because its material therefor costs an arm and a leg, and has seriously limited its application.If can effectively reduce its cost, just can be widely used.

The purpose of this utility model provides a kind of can significantly reducing cost, and takes into account a kind of novel circulator of its compactedness and small size simultaneously.

The purpose of this utility model is achieved in that a kind of novel circulator by double-fiber collimator single fiber collimating apparatus and three optical functions that between the two biprism, wollaston prism, 1/2 wave plate and faraday's revolving fragment form are set make up the three-port circulator that A, B, C form tight structure successively, wherein

A: form by wollaston prism, biprism, two revolving fragment and two 1/2 wave plates of drawing successively;

B: form by biprism and wollaston prism successively;

C: form by two 1/2 wave plate faraday revolving fragments, prism and wollaston prisms successively.

Because this novel double-fiber collimator that adopted, so the entire device volume has been realized miniaturization, these novel another part characteristics are all to adopt wollaston prism and optical prism, adopt the bulk birefringece crystal to compare with traditional endless row device, can significantly reduce cost, thereby have very big practical value and potentiality.

Reaching accompanying drawing now in conjunction with the embodiments further describes

Fig. 1 has United States Patent (USP) light channel structure principle;

Fig. 2 the utility model port one → port 2 light path front views.

Fig. 3 the utility model port one → port 2 light path vertical views.

Fig. 4 the utility model port 2 → port 3 light path front views.

Fig. 5 the utility model port 2 → port 3 light path vertical views.

Fig. 6 the utility model mechanical assembly drawing.

As this novel schematic diagram 2, Fig. 3, Fig. 4, shown in Figure 5, Fig. 2 wherein, Fig. 3 is respectively the light path front view of port one → port 2, vertical view.Fig. 4, Fig. 5 are respectively front view, the vertical view of port 2 → port 3.

As Fig. 2 is the light path front view of circulator port one → port 2, arranges light here and can be decomposed into the parallel paper of polarization state, two kinds of vertical papers.2,17,1 is optical fiber cable, is respectively port one, port 2, port 3.The 3 pairs of optical fiber kapillaries and 4 lenticules constitute double-fiber collimator, 5A, the wollaston prism of 5B for constituting by two orthogonal birefringence wafers of optical axis, 6 is biprism, 7 is faraday's revolving fragment, and 8A, 8B are two 1/2 wave plates of splicing mutually, its optical axis respectively becomes 22.5 ° of angles with the handing-over seam, shown in the 8B of Fig. 2 top.9 is a biprism, 10A, 10B is a wollaston prism, its angle of wedge direction respectively with

wollaston prism

5A, 5B is vertical mutually, 11A, 11B are 1/2 wave plate of same 8A, 8B structure, its optical axis is for the splicing seams symmetry and become 22.5 ° of angles, and 12 is faraday's revolving fragment, and 13 is biprism, 14A, 14B are a wollaston prism, and lenticule 15 constitutes the single fiber collimating apparatus with single fiber head 16.

Analysis chart 2 optical path change at first, light enter from port one that double-fiber collimator is collimated to be directional light, will be decomposed into the orthogonal polarized light of two bundles, a branch of parallel paper, a branch of vertical paper from the directional light of collimating apparatus outgoing by wollaston prism (5A, 5B).If the angle of wedge of wollaston prism is α, the two bundle orthogonal light of polarization state two-beams behind wollaston prism β that has angle then, two angle of wedge sheet optical axis directions of wollaston prism are as shown in Figure 2.The pass of α and β is: β=arcsin{n _e.sin[α-arcsin (n ₀/ n _e.sin α)] }+arcsin{n _o.sin[arcsin (n _e/ n ₀Sin α)-α] (1)

During to biprism 6, being proofreaied and correct by biprism 6 is the light that two bundles are parallel to each other through the two-beam of

wollaston prism

5A, 5B, and establishing the biprism angle of wedge is two angle same δ, and then δ and β pass is:

δ＝arctg{(sin(β/2))/{ncos{arcsin[(sin(β/2))/n]}-1)}(2)，

Wherein n is the refractive index of biprism glass.The distance of

wollaston prism

5A, 5B and biprism 6 is separated for the hot spot that guarantees two-beam and is not caused on middle edge that Insertion Loss is as the criterion during by biprism 6.That will talk about below constitutes optical block with aforementioned said function by biprism 13 and

wollaston prism

14A, 14B, and distance corresponding between them equates.Faraday's revolving fragment 7,1/2

wave plate

8A, 8B is combined into one.Wherein, for faraday's revolving fragment 7, frontlighting road direction is seen the time by counterclockwise rotating 45 °, 1/2

wave plate

8A, 8B optical axis direction and between them splicing be seamed into 22.5 °, it is the light of identical polarization direction that this wave plate combined body is restrainted the orthogonal phototransformation of polarization states to two.2 (c) represent the sense of rotation and the 1/2 wave plate 8A of faraday's revolving fragment 7 respectively among Fig. 2, the optical axis direction of 8B (along the light path working direction), 2 (b) represent that respectively light enters faraday's revolving fragment 7 preceding polarization directions among Fig. 2, enter faraday's revolving fragment 7 rear polarizer directions and enter 1/2

wave plate

8A, 8B rear polarizer direction, we can be

wollaston prism

5A, 5B, biprism 6, faraday's revolving fragment 7,1/2

wave plate

8A, 8B makes up A as optical function, can be decomposed into the directional light behind a branch of collimation on the two bundle spaces and be separated from each other, the optical function combination that polarization is identical, the function of A can regard that forming two restraints polarization orthogonal in the light of paper as in Fig. 2.The optical function piece II of two-beam through being made of biprism 9 and

wollaston prism

10A, 10B, the identical light light path in front view of this two bundle polarization does not change, and is embodied in light path generation deviation in the vertical view 3, describes when this will narrate Fig. 3 below.The identical light of two bundle polarization states passes through 1/2

wave plate

11A, 11B, to become the mutual orthogonal polarized light of two bundles behind faraday's revolving fragment 12 again, just polarization state with by wollaston prism 5A, just in time opposite during 5B, 1/2 wave plate 11A wherein, the 11B structure is with 1/2 wave plate 8A, the 8B optical axis direction is also identical, 2 (d) represent 1/2 wave plate 11A respectively among Fig. 2, the sense of rotation of the optical axis direction of 11B and faraday's revolving fragment 12,2 (e) represent to enter 1/2 wave plate 11A respectively among Fig. 2, light polarization before the 11B, light beam is by 1/2

wave plate

11A, 11B rear polarizer attitude and by faraday's revolving fragment 12 rear polarizer attitudes.Light is by 1/2

wave plate

11A, 11B and faraday's revolving fragment 12 backs arrive biprism 13, reflected into the orthogonal light beam that crosses of two bundle polarization states by biprism 13 then, a wollaston prism 14A of its intersection, the optical axis direction of 14B respectively with wollaston prism 5A, the optical axis direction of 5B becomes 90 °, as shown in Figure 2.In general, 6,13 is the biprism that two angles of wedge equate,

wollaston prism

14A, 14B get with the angle of wedge that equates with

wollaston prism

5A, 5B, and also desirable certainly different value is as long as can realize identical function, but there is no need here to do like this, the identical angle of wedge will bring the convenience in the processing.Here can be with 1/2

wave plate

11A, 11B, faraday's revolving fragment 12, biprism 13,

wollaston prism

14A, 14B are regarded one group of optical function spare C as, and it is combined into the identical light of two bundle polarizations with the orthogonal light of a branch of polarization state again.Single

fiber collimating apparatus

15,16 constitutes the single fiber collimating apparatus, receives the light by wollaston prism 114A, 14B.Circulator is realized from port one to port 2 function like this.

We see Fig. 3 again, and this is from vertical view analysis 2 light courses from the port one to the port.Pass A group optical module from the port one emergent light with certain drift angle, from vertical view, the two-beam that separates on Fig. 2 becomes a projection that overlaps here, and deviation does not take place.9 is biprism, and establishing the angle of wedge is γ, and when the port one of double-fiber collimator, 2 advance the light time simultaneously, is θ by biprism 9 two-beam angles, and it is γ＞θ that γ and θ close, usually γ=2 θ.Arriving biprism 9 light beams is the light of same polarization state, it enters wollaston prism 10A after prismatic refraction, 10B, light beam reflects once more, wollaston prism 10A, and the 10B optical axis direction is seen shown in Figure 3, if wollaston prism 10A, the angle of wedge of 10B is λ, and the value of λ and double-fiber collimator twin-beam angle theta, biprism 9 wedge angle gamma are directly related, and its relational expression can be written as:

nsin{γ-[arcsin(sin(φ/2))/n]}＝sin(φ/2) (3)

φ=arcsin[(n wherein _o-n _e) tan λ], n is the refractive index of biprism 9.

We are analysis chart 4, two groups of index paths of Fig. 5 again, and its expression light enters the index path that arrives optical fiber 1 (port 3) from optical fiber 17 (port 2).Organize optical element from the directional light of single fiber collimating apparatus 15 outgoing by C, this moment, C group optical element function was with identical from the light of the lenticule 4 outgoing optical function during by A group optical element, and the polarization state when frontlighting road direction that different is is seen polarization state and organized optical element by A is just vertical.Promptly for Fig. 4, the parallel paper of its polarization state, just in time perpendicular with the situation of Fig. 2.By the two-beam of C group optical element, not change of direction on Fig. 4 during again by B group optical element.(4 (b) among Fig. 4, be respectively along optical path direction and see faraday's revolving fragment 12,1/2 wave plate 11A, the sense of rotation of 11B and optical axis direction, two-beam was by faraday's revolving fragment 12 preceding polarization directions when three of 4 (c) figure were respectively the frontlighting road among Fig. 4, by faraday's revolving fragment 12 polarization rears to, by polarisation of light direction behind 1/2 wave plate 11A, the 11B).Light enters A group optical element after organizing optical element by B, (two identical light beams of polarization can be converted into the orthogonal optical module of polarization state), be combined into a branch of light through Wo Lasi

prism

5B, 5A again and enter lenticule 4, to optical fiber 1, it is port 3, this moment, A group function was organized function with the C among Fig. 2, promptly closed Shu Zuoyong.Fig. 4 represents the sense of rotation of optical axis direction and the 7 pairs of light polarizations of faraday's revolving fragment of 1/2

wave plate

8A, 8B when optical path direction respectively, three figure of 4 (e) represent that respectively two bundle polarized lights advance before 1/2 wave plate 8A, the 8B among Fig. 4, enter after 1/2 wave plate 8A, the 8B and advance light beam polarization direction after faraday's revolving fragment 7.

Fig. 5 represents that light overlooks index path from port 2 input during by C group, B group, A group optical element.The similar Fig. 3 of this light path, different is by among Fig. 5 during optical module C polarization state perpendicular to paper, by Wo Lasi prism 10B, the downward deviation of 10A rear polarizer light, again by the biprism 9 back light deviation that makes progress, behind A, light beam closes bundle and enters optical fiber 1, and promptly port 3.

In conjunction with Fig. 3, Fig. 5 as can be seen, the effect of

wollaston prism

10A, 10B is in the light path: when light when port one is imported, in Fig. 3, show as parallel paper light, by the time still be parallel paper, upwards be angled to horizon light, when light during from port 2 input, in Fig. 5, show as vertical paper light by the time still be vertical paper, deviation downwards.Like this, the structure of this patent realizes the function of three-port circulator, and promptly port one → port 2; Port 2 → port 3.

Because this novel double-fiber collimator that adopted, so the entire device volume has been realized miniaturization, another characteristics of this patent are all to adopt wollaston prism and optical prism, adopt the bulk birefringece crystal to compare with the traditional endless device, can significantly reduce cost, thereby have very big practical value and potentiality.

This new mechanical wiring layout as shown in Figure 6,1,2,17 is optical fiber cable, is respectively circulator port 3, port one,

port

2,23,24 is an optical fiber cable rubber sheath, and 18,22 are the end sleeve pipe, and 3 is double-fiber collimator, 20 is scolding tin, and 19 is metal-coating, 10A, 10B; 14A, 14B; Respectively be one group of wollaston prism, 6,9,13 is biprism, and 7,12 for carrying faraday's revolving fragment in magnetic field, 5A, 5B; 8A, 8B; 11A, 11B are 1/2 wave plate, and 25 is the Metal Packaging sheet.The fixing epoxy glue bonding that all adopts of optical element and shell.

Claims

1. a novel circulator is made up of double-fiber collimator (3,4) single fiber collimating apparatus (15,16) and setting optical element between the two, it is characterized in that also being provided with between the collimating apparatus three-port circulator that forms tight structure by biprism, wollaston prism, 1/2 wave plate and three optical function combinations of faraday's revolving fragment A, B, C successively, wherein

A: successively by wollaston prism (5A, 5B), biprism (6), two revolving fragment (7) that draws

And two 1/2 wave plates (8A, 8B) are formed;

B: form by biprism (9) and wollaston prism (10A, 10B) successively;

C: successively by two 1/2 wave plate (11A, 11B) faraday's revolving fragments (12), biprism (13)

Form with wollaston prism (14A, 14B).