CN1761899A - Optical collimator - Google Patents

Abstract

An optical collimator, comprising a sleeve, a partially spherical surface lens, and a capillary holding an optical fiber, the sleeve further comprising an inner hole disposed concentrically to the outer peripheral surface thereof, and the partially spherical surface lens further comprising a cylindrical part fixedly inserted into the inner hole of the sleeve and light transmission spherical faces provided at both ends of the cylindrical part. The optical axis of the light transmission spherical faces is positioned eccentrically to the center axis of the outer peripheral surface of the sleeve. The capillary is fixedly inserted into the inner hole of the sleeve, and holds the optical fiber at a position eccentric to the center axis of the outer peripheral surface of the sleeve to face the tilted end face of the optical fiber toward the partially spherical surface lens.

Description

Optical collimator

Technical field

The present invention relates to a kind ofly have kapillary, the part is the lens of sphere and the optical collimator of sleeve, the optical fiber that has optical communication to use in internal fixation capillaceous, the lens that the part is sphere have columnar portion and printing opacity sphere, sleeve, coaxial with kapillary and the local lens that are sphere.

Background technology

When constructing the optical fiber telecommunications system of high-speed high capacity, to use more optical device, comprising the optical crystal body light signal that from the compound light signal of a plurality of wavelength, takes out any wavelength and that utilize the phase place unanimity that makes light signal etc., in order will to penetrate and the light signal of diffusion to be become directional light or for directional light is concentrated on the optical fiber, and to use a plurality of optical collimators from optical fiber.

As shown in Figure 6, use part in the past is the optical collimator 1 of the lens of sphere, and kapillary 4 and the local lens 3 that are sphere are inserted in the sleeve 2, carries out aligning, and is fixing with bonding agent 6 again, so that the optical position relation is suitably, and as the optical collimator correct operation.This kapillary optical fiber 5 is fixed on inner in, form inclination abrasive surface 4a in order to prevent the light that reflects from the end face 5a of optical fiber 5.

As the technology of this optical system, the central shaft that discloses in the patent documentation 1 for the directional light that makes incident/ejaculation and the optical collimator that has used the local lens that are sphere does not have off-centre, uses the inclination grinding optical element with regulation shape and refractive index.The technology of the optical axis that makes optical fiber and collimation lens and the eccentricity of central axis of the outer peripheral face of the sleeve that supports them is disclosed in patent documentation 2.Disclose in patent documentation 3 that the inclination grinding angle that has ground the optical fiber of end with inclination makes the central shaft translational offsets of optical fiber and lens accordingly and the optical collimator that forms parallel beam.The optical connector that the center of tubular shell is decided to be the center line of the parallel beam that penetrates through globe lens is disclosed in patent documentation 4.And, a kind of optical fiber collimator is disclosed in patent documentation 5, it makes the center off-centre of the optical axis and the lens of optical fiber, and sets offset, so that the center of lens is roughly consistent with the center of the light beam that comes out from optical fiber that is incident to lens.In patent documentation 6, disclose from the optical axis collimating apparatus parallel of the light beam of lens ejaculation with the optical axis of optical fiber.The optical fiber collimator that the optical fiber end face of lens by accommodating substantial cylindrical in lens fixed mount cylindraceous and optical fiber of disclosing in patent documentation 7 constitutes coaxial shape.

Patent documentation 1: the spy opens the 2001-56418 communique

Patent documentation 2: the spy opens flat 9-258059 communique

Patent documentation 3: the spy opens clear 62-235909 communique

Patent documentation 4: the spy opens flat 2-111904 communique

Patent documentation 5: the spy opens the 2002-196180 communique

Patent documentation 6: the spy opens flat 5-157992 communique

Patent documentation 7: the spy opens flat 9-274160 communique

In conventional art structure shown in Figure 6, owing to use kapillary 4, and this kapillary 4 is when being fixed on optical fiber 5 inside, in order to prevent the light that reflects from the end face 5a of optical fiber 5 and be formed with inclination abrasive surface 4a, so can penetrate along direction from the end face 5a of optical fiber 5 with optical axis Y inclination capillaceous according to refraction principle light, its result, the directional light 7 that penetrates from optical collimator 1 has the problem that produces the off-centre of offset δ between the central shaft A of the outer peripheral face of the optical axis Z of directional light and optical collimator 1.

And for example shown in Figure 7, when the optical collimator 1 that uses structure in the past and light function element 8a assemble light functional part 8, because the central shaft A off-centre of the optical axis Z of directional light 7 and the outer peripheral face of optical collimator 1, therefore need make the eccentric direction unanimity of each optical collimator 1 exactly, like this, the non-constant of operation.

In addition, as shown in Figure 8, utilizing internal fixation optical fiber 15 and do not making directional light 17 under the situation of the central shaft A incident/ejaculation of the outer peripheral face of optical collimator 11 with sleeve 12 at the kapillary of implementing on the end face 14a to tilt to grind 14, owing to can not get the reflection loss amount that the effect of grinding produces, so it is very big with the light that the local printing opacity land portions 13c that is the lens 13 of sphere reflects from the end face 15a of optical fiber 15, even add antireflection film in its surface respectively, can not fully stop the light that reflects.And, because this light that reflects has harmful effect to LASER Light Source etc., therefore when constructing the optical fiber telecommunications system of high-speed high capacity, big problem is arranged in the practicality.

Patent documentation 1 is shown in Figure 1 for another example, and under the situation of the inclination grinding optical element that uses both ends of the surface to be ground by parallel oblique, the operation that needs accurate aligning is so that the central shaft incident/ejaculation of the relative optical collimator of directional light, the non-constant of operation.In addition, owing to insert inclination grinding optical element in light path, so the insertion of optical collimator loss increases, the insertion loss of increase becomes a problem when constructing the optical fiber telecommunications system of high-speed high capacity.

In addition, shown in Figure 9 as patent documentation 1 cut under the situation of metal cylindric fixed mount at internal diameter center the Precision Machining that is staggered a little in external diameter and internal diameter center using with the external diameter center with staggering.In addition, owing to be between the lens of sphere at metal cylindric fixed mount, with the kapillary of internal fixation optical fiber and part and have coefficient of thermal expansion differences, so under the bigger situation of this difference, the swell increment or the amount of contraction difference of each constitutive requirements that produce because of variation of temperature when using, and cause optical characteristics confusion (instability).Particularly, owing to produce this expansion or shrink poor, produce on the lens of sphere under the situation that stress concentrates and be in the part, by the fault increase that optical characteristics confusions such as refractive index or dispersion cause, the stability of optical system becomes problem.

For this reason, differ under the bigger temperature conditions with room temperature when high temperature or during low temperature etc., not only on the adhesive portion of sleeve and kapillary and sleeve and the local lens that are sphere, produce and peel off and there is infringement on internal ground to characteristics of components, and produce distortion on the local lens that are sphere and make through the light quantity variation, make the partial wave characteristic variations or can not get stable collimated light.Its result has limited the environment for use of this optical communication with device, and is particularly bigger in the outdoor application restriction; When group is gone in the optical device, require high-precision optical characteristics simultaneously, therefore the temperature range that may use is extremely narrow, and the restriction during use is strict more.

In addition, in patent documentation 2, as shown in Figure 9, a kind of following structure is disclosed, promptly, utilize eccentric adjusting sleeve 22, make optical fiber 25 and the local optical axis X that is the lens 23 of sphere, with the central shaft B off-centre of the outer peripheral face of eccentric adjusting sleeve 22, make the central shaft A of the outer peripheral face of the optical axis Z of directional light 27 of incident/ejaculation and optical collimator 21 not have off-centre.In this case, because the optical axis Z of the central shaft D of the outer peripheral face of the local lens 23 that are sphere and the directional light 27 of incident/ejaculation is inconsistent, even so the diameter of the directional light 27 of incident/ejaculation than the little situation of the external diameter of the local lens 23 that are sphere under, also can be because of the off-centre of both central shafts, the external diameter that makes the part be the lens 23 of sphere can not be reduced to the degree of the diameter of incident/ejaculation directional light 27.Therefore, the optical axis Z of the directional light 27 of incident/ejaculation does not have off-centre with the central shaft of the outer peripheral face of the optical collimator 21 that has used the local lens 23 that are sphere, and, also a big problem when realizing the thin footpath of optical collimator 21.

In addition, as shown in figure 10, under the situation of the optical collimator with long operating distance 31 that is used for mechanical type optical switch etc.,, use the lens 33 that are sphere than the part of larger radius of curvature in order to realize long operating distance.If radius-of-curvature is big, the then local focal length that is the lens 33 of sphere becomes big, in the form of using eccentric adjusting sleeve 32, its result, the off-centre of the central shaft D of the outer peripheral face of the optical axis Z of the directional light 37 of incident/ejaculation and the local lens 33 that are sphere becomes big, simultaneously, the diameter of the directional light 37 of incident/ejaculation also becomes big.Therefore, reduce external diameter that the part is the lens 33 of the sphere difficulty that more and more becomes, the central shaft of the optical axis Z of the directional light 37 of incident/ejaculation and the optical collimator 31 that has used the local lens 33 that are sphere do not have eccentric in, also be difficult to realize the thin footpathization of optical collimator 31.In addition, even do not consider incident/ejaculation directional light 37 diameter and, the off-centre of optical axis Z and the central shaft D of the outer peripheral face of the local lens 33 that are sphere, and make the part be the thin footpathization of diameter of the lens 33 of sphere, then as shown in figure 10, the directional light 37 of incident/ejaculation can produce damaged 37a, it is big to insert loss, so also is a big problem in the practicality.

In addition, as described in patent documentation 2, the central shaft of the directional light of incident/ejaculation and optical collimator does not have under the eccentric situation using eccentric adjusting sleeve, because the central shaft of the outer peripheral face central shaft of the local lens that are sphere and the directional light of incident/ejaculation is inconsistent, so even the diameter of the directional light of incident/ejaculation is than the external diameter of the local lens that are sphere hour, also because the influence of the two eccentricity of central axis, and the external diameter that the part can not be the lens of sphere is reduced to the diameter degree of the directional light of incident/ejaculation, its result, the thin footpathization that can hinder optical collimator.

And for example patent documentation 3 is shown in Figure 1, grinding angle in the inclination of the optical fiber that has ground the end according to inclination forms under the situation of optical collimator of parallel beam the central shaft translation dislocation of optical fiber and lens, because the optical axis of the parallel beam that penetrates is not consistent with the central shaft of optical fiber, therefore, optical collimator aligning operation to each other is very bothersome.

In addition, shown in Figure 2 as patent documentation 4, in the inconsistent structure of optical axis of the core center line of optical fiber and light beam, the optical axis that for example needs to utilize photodetector to make light beam is with after mechanical axis is consistent, carry out machining (with reference to Fig. 3 of patent documentation 4) to tubular shell again.In addition, have in use under the situation of globe lens of tabular surface of ideal dimensions (with reference to Fig. 4 of patent documentation 4), during assembling, must strictly adjust this tabular surface and the formed angle of optical axis of the light beam that penetrates from optical fiber.

Patent documentation 5 is shown in Figure 1 for another example, about the center of optical axis that makes optical fiber and rod lens with distributed refractive index eccentric and set offset so that have distributed refractive index rod lens the center and incide the roughly consistent structure in center of the light beam on these lens, under the situation of the rod lens that utilizes globe lens to replace to have distributed refractive index, because the optical axis and the lens center off-centre of optical fiber, so the optical axis of light beam that penetrates and optical fiber is inconsistent.

In addition, in the structure shown in the patent documentation 6, though it is parallel with the axle of input side support from the light beam that lens penetrate, but it is and inconsistent, parallel beam (with reference to Fig. 3 of patent documentation 6) just spaced apart with the axle of input side support, therefore, need one side to be the center rotation, optical collimator to be carried out aligning to each other on one side with the axle of support.

In addition, in patent documentation 7, though coaxial end of accommodating the lens and the optical fiber of substantial cylindrical in lens fixed mount cylindraceous, constitute optical collimator (with reference to Fig. 1 of patent documentation 7), yet under the situation of the optical fiber end of spherical lens of accommodating substantial cylindrical coaxially and optical fiber, the optical axis and the optical fiber collimator external diameter central shaft of the directional light that penetrates from optical collimator are inconsistent, therefore, adjusting optical collimator to each other the time, the axle that need make it with optical collimator is the center rotation.

Like this, when utilizing in the past optical collimator to carry out to each other aligning operation of optical collimator, only make each optical collimator on 1 V groove for example, with in the position of the operating distance that becomes them and the central shaft of each sleeve outer peripheral face state consistent with each other relatively to, during like this from an optical fiber lead-in light, can not obtain sufficient photoresponse from another optical fiber.Therefore, for automatic aligning device of using optical axis etc., need manually carry out the aligning operation up to the state that obtains sufficient photoresponse.

Summary of the invention

The object of the invention provides a kind of when carrying out the assembling of light functional part etc., do not need in the past optical collimator to be used to make the aligning operation of eccentric direction unanimity of the directional light of incident/ejaculation like that, parallel luminous energy is with respect to the optical collimator of the central shaft incident/ejaculation of the outer peripheral face of optical collimator.

Another object of the present invention be reduce as far as possible sleeve when under the various temperature condition, using, with the local lens of sphere and the optical characteristics variation that coefficient of thermal expansion differences capillaceous causes of being.

A further object of the present invention is when reducing the optical collimator diameter, reduces as far as possible or eliminate the off-centre of optical axis Z of the directional light of the outer peripheral face central shaft of the optical collimator that uses the local lens that are sphere and incident/ejaculation.

In order to achieve the above object, the invention provides a kind of optical collimator, have: sleeve has the endoporus concentric with outer peripheral face; The part is the lens of sphere, has the columnar portion in the endoporus that inserts sleeve and is located at the printing opacity sphere at the two ends of columnar portion, and the optical axis of this printing opacity sphere is positioned at the position with the eccentricity of central axis of the outer peripheral face of sleeve; Kapillary is inserted in the endoporus of sleeve, with the position of the eccentricity of central axis of the outer peripheral face of above-mentioned sleeve on fixed fiber, the end face of the inclination of this optical fiber is the lens of sphere towards the part.

Optical collimator of the present invention, in the above-described configuration, preferably: being the central shaft that the optical axis of the directional light that the printing opacity sphere in the outside of the lens of sphere penetrates is positioned at the sleeve outer peripheral face from the part is in the scope of center, radius 0.02mm, and the central shaft that is positioned at the outer peripheral face of sleeve is angled in the scope of 0.2 degree.

Specifically, preferred as optical collimator of the present invention: as to have lens and kapillary that sleeve cylindraceous, part are sphere.The central authorities of above-mentioned sleeve are provided with endoporus.The part is the lens of sphere, make by the roughly uniform glass of refractive index, two ends in the diameter columnar portion slightly littler than the endoporus of above-mentioned sleeve have the roughly the same printing opacity sphere of the center of curvature, when insertion is fixed in the above-mentioned sleeve endoporus, become optical axis with the quantitative position of the depth of parallelism eccentric gauge of regulation with the outer peripheral face central shaft of above-mentioned sleeve.Kapillary has the external diameter slightly littler than the endoporus of above-mentioned sleeve, when insertion is fixed in the endoporus of above-mentioned sleeve, the optical fiber of end slope is fixed on and the central shaft of the outer peripheral face of the above-mentioned sleeve quantitative position of depth of parallelism eccentric gauge with regulation.And, more preferably: being the central shaft that the optical axis of the directional light that the printing opacity sphere in the outside of the lens of sphere penetrates is positioned at above-mentioned sleeve outer peripheral face from above-mentioned part is in the scope of center, radius 0.02mm, and the central shaft that is positioned at the outer peripheral face of above-mentioned sleeve is angled in the scope of 0.2 degree.

Optical collimator of the present invention when assembling light functional part etc., need not the optical collimator as in the past, makes the aligning operation of eccentric direction unanimity of the directional light of incident/ejaculation.Therefore, can make the optical collimator of directional light easily with respect to the central shaft incident/ejaculation of the outer peripheral face of optical collimator.In addition, can reduce under the various temperature condition as far as possible sleeve when using, with the local lens of sphere and the optical characteristics variation that coefficient of thermal expansion differences capillaceous causes of being.Therefore, can make light functional part with high reliability.

In addition, optical collimator of the present invention, owing to use the part that becomes optical axis with the quantitative position of the depth of parallelism eccentric gauge of regulation with the central shaft of the outer peripheral face of sleeve to be the lens of sphere, so, can make the optical axis of directional light of incident/ejaculation consistent, can reduce the part and be the external diameter of lens of sphere up to the roughly the same degree of diameter that becomes with the directional light of incident/ejaculation with the central shaft of the outer peripheral face of the local lens that are sphere.In view of the above, can realize the thin footpathization of optical collimator.

In addition, by constituting: under the outer peripheral face central shaft that makes above-mentioned each sleeve state consistent with each other, a pair of above-mentioned optical collimator is assemblied in the position of the operating distance that becomes this a pair of above-mentioned optical collimator, when from the optical fiber lead-in light of an above-mentioned optical collimator, obtain-photoresponse more than the 30dB from the optical fiber of another above-mentioned optical collimator, thereby, need not loaded down with trivial details manual aligning operation, can utilize the automatic aligning device etc. of optical axis to carry out the optical axis aligning of a pair of optical collimator of subtend assembling simply, can realize the assembling of optical fiber with the high-level efficiency that never had in the past.

In said structure, during as the material of sleeve, the available stretch method obtains high-precision cylindricity with glass or devitrified glass, and, can stablize, make in a large number expeditiously.In addition, with the sleeve that pulling method is made, flame polish is used on the surface, and need not lapped face, therefore can make cheaply.

In addition, in said structure, during as material capillaceous, can obtain high-precision cylindricity and offset (also claiming an axle deviator), and can stablize and make in a large number expeditiously with pulling method with glass or devitrified glass.In addition, the capillary surface made from pulling method can flame polish, need not lapped face, therefore, and marked down manufacturing.

In addition, in said structure, be controlled at 50 * 10 by lens and the mutual difference of thermal expansion coefficient of kapillary that sleeve, part is sphere ^-7In/the K, and the optical characteristics variation that causes by mutual difference of thermal expansion coefficient can be reduced as far as possible, optical collimator can be realized keeping the variation of ambient temperature stability.

In addition, in the above-described configuration, preferred: kapillary is by the pulling method manufacturing.

Description of drawings

Fig. 1 (A) is the cut-open view of the optical collimator of embodiments of the invention; Fig. 1 (B) is a side view.

The capillaceous cut-open view of Fig. 2 (A) for using in the optical collimator of embodiments of the invention; Fig. 2 (B) is a side view.

Fig. 3 (A) is the cut-open view of the lens of sphere for the part of using in the optical collimator of embodiments of the invention; Fig. 3 (B) is a side view.

Fig. 4 (A) is the cut-open view of the sleeve that uses in the optical collimator of embodiments of the invention; Fig. 4 (B) is a side view.

Fig. 5 (A) has the cut-open view of the optical collimator of long operating distance for an alternative embodiment of the invention; Fig. 5 (B) is a side view.

Fig. 6 (A) is the cut-open view of the direction parallel with optical axis of optical collimator in the past; Fig. 6 (B) is the cut-open view of the direction vertical with optical axis.

Fig. 7 is the cut-open view of the light functional part of use optical collimator in the past.

Fig. 8 (A) is the cut-open view of the optical collimator in the past of the grinding of not tilting on fiber end face; Fig. 8 (B) is a side view.

Fig. 9 (A) is the cut-open view that has used the optical collimator in the past of eccentric adjusting sleeve; Fig. 9 (B) is a side view.

Figure 10 (A) is the cut-open view that has used the optical collimator in the past with long operating distance of eccentric adjusting sleeve; Figure 10 (B) is a side view.

Figure 11 be make a pair of optical collimator with in the position of the operating distance that becomes them and the central shaft state consistent with each other of the outer peripheral face of each sleeve be assemblied in the cut-open view of 1 situation on the V groove relatively to ground.

Embodiment

Below, with reference to accompanying drawing embodiments of the invention are described.

As Fig. 1～shown in Figure 4, the optical collimator 41 of present embodiment has lens 43 and the kapillary 44 that sleeve 42 cylindraceous, part are sphere.The central authorities of above-mentioned sleeve 42 have endoporus 42a.The part is the lens 43 of sphere, two end 43b at the columnar portion 43a that is made by the roughly uniform glass of refractive index have the roughly the same printing opacity sphere 43c of the center of curvature, when insertion was fixed among the endoporus 42a of sleeve 42, the position quantitative with the outer peripheral face central shaft B eccentric gauge of sleeve 42 became optical axis X.Kapillary 44 when insertion is fixed among the endoporus 42a of sleeve 42, is fixed on the quantitative position of central shaft B eccentric gauge with the outer peripheral face of sleeve 42 with optical fiber 45.The part is the lens 43 of sphere and the kapillary 44 of fixed fiber 45, fixing optically suitable position, so that as optical collimator, can move accurately in the endoporus 42a of sleeve 42, directional light 47 is from the outer peripheral face central shaft A incident/ejaculation of optical collimator 41.Promptly, the central shaft B that the optical axis Z that is the directional light 47 that the printing opacity sphere 43c in the outside of the lens 43 of sphere penetrates from the part is positioned at the outer peripheral face of sleeve 42 is in the scope of center, radius 0.02mm, and, become in the scope of 0.2 degree angle with the central shaft B of the outer peripheral face of sleeve 42.

As shown in Figure 2, constitute the kapillary 44 of optical collimator 41, the central shaft E that optical fiber 45 is fixed on its outer peripheral face has on the position of regulation offset.Therefore, when kapillary 44 being inserted among the endoporus 42a that is fixed on sleeve 42,, become the state that has the regulation offset with the central shaft B of the outer peripheral face of sleeve 42 by the optical axis Y of the fixing optical fiber 45 of kapillary 44.In addition, the central shaft B of the outer peripheral face of sleeve 42 is consistent with the central shaft of endoporus 42a.

As shown in Figure 3, the part that constitutes optical collimator 41 lens 43 that are sphere with the quantitative position of the central shaft D eccentric gauge of its outer peripheral face on have optical axis X.Therefore, when the lens 43 that the part are sphere inserted among the endoporus 42a that is fixed on sleeve 42, the part was the optical axis X of the lens 43 of sphere, became the quantitative state of central shaft B eccentric gauge with the outer peripheral face of sleeve 42.

Be the material of the lens 43 of sphere as the part, can by refractive index roughly uniformly optical glass etc. constitute, spherical by being processed into, use and can make globe lens with high focus precision.Size and diameter in order to reduce optical collimator 41 can grind around the globe lens with high sphericity, make the lens 43 that the part is sphere.As the glass that uses in the lens 43 that are sphere in the part, be preferably BK7, K3 in the optical glass, TaF3, LaF01, LaSF015 etc.

At least one the most handy glass or devitrified glass are made in sleeve 42 and the kapillary 44.This sleeve 42 and/or kapillary 44 available stretch method high precision and stability and high efficiency rate, low price ground are made.In addition,, can use flame polish, make smooth with the sleeve 42 of pulling method manufacturing and/or the surface of kapillary 44.

For example, the lens 43 that are sphere in the part are made by optical glass (LaSF015), and its thermal expansivity is 74 * 10 ^-7/ K, sleeve 42 are made by borosilicate glass, and its thermal expansivity is 51 * 10 ^-7/ K, kapillary 44 are made by devitrified glass, and its thermal expansivity is 27 * 10 ^-7Under the situation of/K, during 60 ℃ of variation of ambient temperature, the offset of the central shaft A of the optical axis Z of the directional light 47 that mutual difference of thermal expansion coefficient causes and the outer peripheral face of optical collimator 41 changes below 0.0003mm (0.3 micron).In addition, the ejaculation drift angle of directional light 47 (inclination angle of light beam) changes below 0.01 degree.

Relative therewith, be that (thermal expansivity is 184 * 10 to SUS304 with general stainless steel ^-7/ K) to make under the situation of sleeve 42, mutual difference of thermal expansion coefficient is 100 * 10 ^-7More than/the K, the offset of the central shaft A of the optical axis Z of the directional light 47 that causes thus and the outer peripheral face of optical collimator 41 changes and to be about 0.0009mm (0.9 micron), being changed to about 0.03 degree of the ejaculation drift angle of directional light 47 (light beam inclination angle).With the situation comparison of the sleeve made from borosilicate glass 42, distinguished variation about three times.

Therefore, preferably utilize mutual difference of thermal expansion coefficient 50 * 10 ^-7/ K makes optical collimator 41 with interior material, like this, can obtain the optical characteristics for the vary stable of environment temperature.

The part that constitutes optical collimator 41 shown in Figure 1 is the offset δ of the optical axis Y of the central shaft E of outer peripheral face of the offset δ of the central shaft D of outer peripheral face of lens 43 of sphere and optical axis X and kapillary 44 and optical fiber 45, available following formula 1 expression:

Formula 1:

$\mathrm{\&delta;}=\frac{{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="A20048000690200241.png"\; state="\{\{state\}\}">n</figure-callout>}}_3}{2(n_3-n_2)}\&CenterDot;r\&CenterDot;\tan \left[\right\{\arcsin \left(\frac{n_1}{n_2}\sin \mathrm{\&theta;}\right)\}-\mathrm{\&theta;}]$

Wherein, n ₁: the refractive index of the core of optical fiber 45, n ₂: the refractive index of air (in atmosphere time) n ₃: the part is the refractive index of the lens 43 of sphere, r: the part is the radius-of-curvature of the lens 43 of sphere, θ: angle is ground in the inclination of the end face 45a of optical fiber 45.

The example of each parameter when table 1 is illustrated in the material of the lens 43 that use optical glass LaSF015 to be sphere as the part.

Table 1

Project	Value
		n 1	1.4682
n 2	1.0
		n 3	1.7753
r	1.75mm
		θ	8.0 degree

When utilizing above-mentioned each parameter, when calculating the offset δ on the above-mentioned formula 1, obtain 0.13mm.Therefore, under the situation of parameter shown in the table 1, the part of using in the optical collimator 41 of structure shown in Figure 1 is the lens 43 of sphere and the offset δ of kapillary 44, can be 0.13mm.

As shown in Figure 4, in this embodiment, sleeve 42 is made by glass, and external diameter is 1.4mm, and internal diameter is 1.0mm, and total length is 5.0mm.The central shaft B of the outer peripheral face of sleeve 42 is consistent with the central shaft C of endoporus 42a.In addition, the also available devitrified glass of sleeve 42 is made.In addition, if be the difference of thermal expansion coefficient of the lens 43 of sphere or kapillary 44 50 * 10 with the part ^-7In/the K, then as sleeve, the combined sleeve that also can use metal or pottery to make.

As shown in Figure 3, in this embodiment, the part is the lens 43 of sphere is made by the roughly uniform optical glass LaSF015 of refractive index, and the radius-of-curvature r of printing opacity sphere 43c is 1.75mm.In addition, the part is the central shaft D of outer peripheral face of lens 43 of sphere and the offset δ of optical axis X is 0.13mm.In addition, for reducing the reflection on light signal is sphere in the part the printing opacity sphere 43c of lens 43, and be formed with antireflection film (not illustrating among the figure).

As shown in Figure 2, in this embodiment, kapillary 44 is made by glass, and external diameter is 1.0mm, and total length is 4.3mm.Under the state in the endoporus that optical fiber 45 is fixed on kapillary 44, the offset δ of the central shaft E of the outer peripheral face of kapillary 44 and the optical axis Y of single-mode fiber 45 is 0.13mm.In order to reduce the light that reflects from the end face 45a of the optical fiber 45 of the inside that is fixed on kapillary 44, and the end slope grinding of kapillary 44 is made it to be 8 degree with respect to the plane vertical with optical axis Y, and, on end face 45a, form antireflection film (not illustrating among the figure).

As shown in Figure 1, above-mentioned kapillary 44 and the local lens 43 that are sphere insert respectively among the endoporus 42a of sleeve 42, utilizing epoxy is bonding agents 46 such as resin, the end face 45a and the local printing opacity sphere 43c that is the lens 43 of sphere of optical fiber 45 are fixed on the suitable position apart from 0.25mm that optically is separated by, so that optical collimator is correctly worked.

Secondly, the measurement result of the offset (being also referred to as optical axis off-centre) of the central shaft A of the outer peripheral face of the optical axis Z of the ejaculation drift angle (being also referred to as the light beam inclination angle) of the insertion loss of expression optical collimator 41, reflection loss amount (be also referred to as and return loss), directional light 47 and directional light 47 and optical collimator 41 in the table 2.

Table 2

Insert loss	The reflection loss amount	Penetrate the drift angle	The optical axis off-centre of directional light
				0.2dB below	More than the 60dB	0.1 below the degree	0.015mm below

In these are measured, uses the light of wavelength as 1550nm, in addition, inserting loss and be a pair of optical collimator 41 subtends being assembled and making operating distance is to measure under the state of 17.5mm.Here, so-called operating distance is the space length that is in the part that subtend is assembled relative direction under the situation of a pair of optical collimator 41 between the printing opacity sphere 43c of lens 43 of sphere.

As shown in table 2, given play to performance identical with example in the past or more than it about inserting loss and reflection loss amount, embodiment, in the practicality without any problem.

In addition, the ejaculation drift angle of embodiment with example comparison in the past, is extraordinary value below 0.1 degree.And, the optical axis offset of the directional light 47 of embodiment is below 0.015mm, for example shown in Figure 11, with a pair of optical collimator 41 with the central shaft B of the outer peripheral face of the position of the operating distance that is in them and each sleeve 42 state consistent with each other relatively to carrying under the situation on the V-shaped groove that is provided with on the V groove substrate 49, even do not having under the state of aligning, also can obtain the work of automatic aligning device-response of the above light signal of 30dB.After utilizing various optical systems to measure, basically can obtain-the above light signal response of 10dB, usually processing with respect to input signal have-5dB～-response of 1dB scope, for example, in the optical system of Fig. 2, the insertion of light signal loss is for having obtained enough light signal responses about 1.5dB.Thereby, when utilizing the necessary smooth functional part of assembling optical collimator 41 such as automatic aligning device aligning operation to each other, relatively can significantly improve operating efficiency with example in the past.

Secondly, the assemble method of optical collimator 41 is described.

At first, the base glass material that the heating cross sectional shape is for example similar to kapillary 44, utilize methods such as elongation moulding, the offset of making external diameter and be the central shaft Y of the central shaft E of 1.0 ± 0.5 μ m, outer peripheral face and endoporus is the internal diameter rectangular kapillary bigger slightly than the diameter of optical fiber 45 of 0.13mm, endoporus.Secondly, as shown in Figure 2, optical fiber 45 is inserted in the rectangular kapillary endoporus bonding after, with optical fiber 45 rectangular kapillary is cut into desired length, carry out desired processing, manufacturing external diameter 1.0 ± 0.5 μ m, total length is the kapillary 44 of 4.3mm.When inserting kapillary 44 among the endoporus 42a that is fixed on sleeve 42, with optical fiber 45 be fixed on the central shaft B eccentric gauge of the outer peripheral face of sleeve 42 quantitatively (in this example, eccentric 0.13mm) position, on the outer peripheral face of kapillary 44, make mark or directional plane (orientation flat) processing part (the not expression among the figure) of expression eccentric direction.Kapillary 44 also can mechanical eccentric ground carries out periphery and grinds and make.

In addition, as shown in phantom in Figure 3, the globe lens that can use sphericity height and low-cost easy acquisition is as material, so that the mode of the eccentric 0.13mm of the central shaft D of optical axis X and outer peripheral face grinds to form it cylindric, obtain diameter less than 1.0mm, the radius-of-curvature r that the center of curvature of the printing opacity sphere 43c of two ends 43b is positioned at same position, printing opacity sphere 43c is the lens 43 that the part of 1.75mm is sphere.When the lens 43 that the part are sphere insert among the endoporus 42a that is fixed on sleeve 42, with the central shaft B eccentric gauge of the outer peripheral face of sleeve 42 quantitatively (in this example, offset is 0.13mm) the position on have optical axis X, on the part is the outer peripheral face of lens 43 of sphere, make mark or directional plane processing part (not the illustrating among the figure) of expression eccentric direction.

Secondly, the base glass material that heating cross sectional shape and sleeve 42 are similar extends and is shaped, and is cut into desired length, and manufacturing external diameter as shown in Figure 4 is that 1.4mm, internal diameter are 1.0mm and transparent sleeve 42.In addition, when making the lens that are used for making the part be sphere 43 mark consistent with the eccentric direction of kapillary 44 or directional plane processing part (figure does not illustrate) on the outer peripheral face of this sleeve 42, the assembling of optical collimator 41 is carried out easily.

Secondly, the lens that the part are sphere insert among the endoporus 42a of sleeve 42, and mutual mark correspondence is positioned, and are fixing with bonding agent 46 again.After bonding agent 46 hardens fully, kapillary 44 is inserted among the endoporus 42a of sleeve 42, mutual mark correspondence is positioned; Observe simultaneously on one side and locate, and fix with bonding agent 46 so that the end face 45a of optical fiber 45 and part are the distance of sphere 43c of the lens 43 of sphere is 0.25mm ± 2 μ m.Like this, formed optical collimator shown in Figure 1 41.

Fig. 5 represents the optical collimator with long operating distance 51 of another embodiment.The optical collimator 51 of present embodiment has the cylindric sleeve 52 of central zone endoporus 52a, lens 53 and the kapillary 54 that the part is sphere.The part is the lens 53 of sphere, has the roughly the same printing opacity sphere 53c of the center of curvature at the two ends of the columnar portion of being made by the roughly uniform glass of refractive index; When insertion was fixed among the endoporus 52a of sleeve 52, the position quantitative with the central shaft B eccentric gauge of the outer peripheral face of sleeve 52 became optical axis X.Kapillary 54 when insertion is fixed among the endoporus 52a of sleeve 52, is fixed on the quantitative position of central shaft B eccentric gauge with the outer peripheral face of sleeve 52 with optical fiber 55.The kapillary 54 that the part is the lens 53 of sphere and fixed fiber 55 is fixed on the optically suitable position, with can be in the endoporus S2a of sleeve 52 as optical collimator correct operation.Directional light 57 is from the central shaft A incident/ejaculation of the outer peripheral face of optical collimator 51.Promptly, the optical axis Z that is the directional light 57 that the printing opacity sphere 53c in lens 53 outsides of sphere penetrates from the part, the central shaft B with the outer peripheral face of sleeve 52 be center, radius 0.02mm scope with interior and with the outer peripheral face central shaft B of sleeve 52 be angled 0.2 degree with interior scope in.

The part that constitutes optical collimator 51 shown in Figure 5 is the offset δ of the optical axis Y of the central shaft of outer peripheral face of the offset δ of the central shaft D of outer peripheral face of lens 53 of sphere and optical axis X and kapillary 54 and optical fiber 55, available following formula 1 expression.In the formula, n ₁: the refractive index of the core of optical fiber 55, n ₂: the refractive index of air (in atmosphere time) n ₃: the part is the refractive index of the lens 53 of sphere, r: the part is the radius-of-curvature of the lens 53 of sphere, θ: angle is ground in the inclination of the end face 55a of optical fiber 55.

The example of each parameter when table 3 expression uses optical glass LaSF015 to be the material of lens 53 of sphere as the part.

Table 3

Project	Value
		n 1	1.4492
n 2	1.0
		n 3	1.7753
r	2.75mm
		θ	8.0 degree

Utilize above-mentioned each parameter, the offset δ that is calculated by following formula 1 is 0.20mm.Therefore, under the situation of parameter shown in the table 3, the part of using on the optical collimator with long operating distance 51 of structure shown in Figure 5 is the lens 53 of sphere and the offset of kapillary 54 can be 0.20mm.

In this embodiment, sleeve 52 is made by glass, and external diameter is 1.4mm, and internal diameter is 1.0mm, total length 8.0mm.The outer peripheral face central shaft B of sleeve 52 and the central shaft C of endoporus 52a are consistent.In addition, the also available devitrified glass of sleeve 52 is made.In addition, if be the difference of thermal expansion coefficient of the lens 53 of sphere and kapillary 54 50 * 10 with the part ^-7In/the K, then this sleeve can use the combined sleeve that metal or pottery are made.

In this embodiment, the part is the lens 53 of sphere is made by the roughly uniform optical glass LaSF015 of refractive index, and the radius-of-curvature r of printing opacity sphere 53c is 2.75mm.The part is the outer peripheral face central shaft D of lens 53 of sphere and the offset δ of optical axis X is 0.20mm.In addition, in order to reduce the reflection on light signal is sphere in the part the printing opacity sphere 53c of lens 53, can form antireflection film (not illustrating among the figure).

In this embodiment, kapillary is made by glass, and external diameter is 1.0mm, total length 4.3mm.Optical fiber 55 is fixed under the state in the endoporus of kapillary 54, and the offset δ of the central shaft E of the outer peripheral face of kapillary 54 and the optical axis Y of optical fiber 55 is 0.20mm.In order to reduce the light that reflects from the end face 55a that is fixed on inner optical fiber 55, the end face of kapillary 54 grinds to form 8 degree with respect to the plane inclination vertical with Y on the optical axis, and, on end face 55a, form antireflection film (not illustrating among the figure).

Above-mentioned kapillary 54 and the local lens 53 that are sphere are inserted respectively among the endoporus 52a of sleeve 52, to be bonding agent 56 such as resin with kapillary 54 and the local lens 5 that are sphere be fixed on that suitable distance is on the position of 0.40mm on the optics of printing opacity sphere 53 of the end face 55a that makes optical fiber 55 and the local lens 53 that are sphere with epoxy, so that optical collimator correctly moves.

Secondly, expression has the measurement result of offset (also claiming optical axis off-centre) of the outer peripheral face central shaft A of the optical axis Z of the ejaculation drift angle (being also referred to as the light beam inclination angle) of insertion loss, reflection loss amount (be also referred to as and return loss), directional light 57 of the optical collimator 51 of long operating distance and directional light 57 and optical collimator 51 in the table 4.

Table 4

Insert loss	The reflection loss amount	Penetrate the drift angle	The optical axis off-centre of directional light
				0.3dB below	More than the 60dB	0.1 below the degree	0.015mm below

In these are measured, use the light of wavelength as 1550nm.In addition, inserting loss is with a pair of optical collimator 51 subtends assembling and to make operating distance be to measure under the state of 150mm.Here, so-called operating distance be subtend assemble under the situation of a pair of optical collimator 51 relatively to the part be between the printing opacity sphere 53c of lens 53 of sphere space length.

As shown in table 4, about inserting loss and reflection loss amount, embodiment brings into play performance identical with example in the past or more than it, and is no problem in the practicality.

In addition, the ejaculation drift angle of embodiment with the comparison of example in the past of the optical collimator with long operating distance, is extraordinary value below 0.1 degree.The optical axis offset of the directional light 57 of embodiment is below 0.015mm, for example, with identical situation shown in Figure 11 under, with a pair of optical collimator 51 with the central shaft B of the outer peripheral face of the position of the long operating distance that is in them and each sleeve 52 state consistent with each other relatively to carrying under the situation on the V-shaped groove, even do not having under the state of aligning, for input signal also can obtain the work of automatic aligning device-response of light signal more than the 30dB.For example, in the optical system of Fig. 5, under the best situation, the insertion of light signal loss is for having obtained enough light signal responses about 1.0dB.Thereby, when assemblings such as utilizing the automatic aligning device need have the light functional part of optical collimator 51 aligning operation to each other of long operating distance, with the example in the past with long operating distance relatively, can significantly improve operating efficiency.

In addition, the optical collimator 51 of present embodiment, no matter whether have the long operating distance of 150mm, the external diameter that all part can be the lens 53 of sphere is reduced to 1.0mm, and can realize that external diameter is reduced to the thin footpathization of 1.4mm.Yet, as shown in figure 10, using eccentric adjusting sleeve 32, manufacturing has under the situation of optical collimator 31 of operating distance of 150mm, when the external diameter of the lens 33 that the part are sphere is reduced to 1.0mm, produce damaged 37a in the directional light 37 of incident/ejaculation, the result produces the insertion loss about 1.0dB, is a big problem in the practicality.On the other hand, even the external diameter that makes the part be the lens 33 of sphere in order not produce damaged 37a in the directional light 37 of incident/ejaculation is made 1.25mm,, be that 1.4mm, internal diameter are the eccentric adjusting sleeve 32 of 1.0mm also so physically can not make external diameter because the offset of the optical axis Z of the directional light 37 of the outer peripheral face central shaft X of the local lens 33 that are sphere and incident/ejaculation is 0.20mm.Therefore, must use the eccentric adjusting sleeve 32 of external diameter as 1.8mm.That is, when being scaled axial sectional area, the optical collimator 51 of present embodiment, with optical collimator 31 comparisons in the past, diameter can be reduced to 0.6 times.

Claims (8)

1. optical collimator is characterized in that having:

Sleeve has the endoporus concentric with outer peripheral face;

The part is the lens of sphere, has the columnar portion in the endoporus that inserts above-mentioned sleeve and is located at the printing opacity sphere at the two ends of this columnar portion, and the optical axis of this printing opacity sphere is positioned at the position with the eccentricity of central axis of the outer peripheral face of above-mentioned sleeve;

Kapillary is inserted in the endoporus of above-mentioned sleeve, with the position of the eccentricity of central axis of the outer peripheral face of above-mentioned sleeve on fixed fiber, and the end face of the inclination of this optical fiber is aimed at the local lens that are sphere.

2, optical collimator as claimed in claim 1, it is characterized in that, being the central shaft that the optical axis of the directional light that the printing opacity sphere in the outside of the lens of sphere penetrates is positioned at above-mentioned sleeve outer peripheral face from above-mentioned part is in the scope of center, radius 0.02mm, and the central shaft that is positioned at the outer peripheral face of above-mentioned sleeve is angled in the scope of 0.2 degree.

3, optical collimator as claimed in claim 1 is characterized in that,

Under the outer peripheral face central shaft that makes above-mentioned each sleeve state consistent with each other, a pair of above-mentioned optical collimator is assemblied in the position in the operating distance of this a pair of optical collimator, and when making it from the optical fiber lead-in light of an above-mentioned optical collimator, can from another relatively the optical fiber of the above-mentioned optical collimator of configuration obtain-photoresponse more than the 30dB.

4, optical collimator as claimed in claim 1 is characterized in that, above-mentioned sleeve is made by glass or devitrified glass.

5, optical collimator as claimed in claim 1 is characterized in that, above-mentioned sleeve is a combined sleeve.

6, optical collimator as claimed in claim 1 is characterized in that, above-mentioned kapillary is made by glass or devitrified glass.

7, optical collimator as claimed in claim 1 is characterized in that, above-mentioned sleeve, above-mentioned part are the mutual difference of thermal expansion coefficient of the lens of sphere and kapillary 50 * 10 ^-7In/the K.

8, optical collimator as claimed in claim 1 is characterized in that, above-mentioned kapillary is by the pulling method manufacturing.

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