CN1249483C - Optical system with laser beam uniform irradiation - Google Patents

Abstract

An optical system with laser beam uniform irradiation, comprises: a wave-guide space-dividing a laser beam from a light source into divided beams; a superposition lens by which the divided beams are superposition-irradiated on an irradiation face; a delay plate by which beam intensity on the irradiation face is uniform. The wave-guide makes width of the divided beams more than 1/2 times large of a space interference distance on a laser beam section; the delay plate makes a delay of the adjacent divided beams longer than an interference distance of the time of the laser beam, and reduces interference on the irradiation face. An other optical system comprises: a laser beam dividing component for dividing the laser beam into divided beams; a superposition-irradiation component for superposition-irradiating the divided beams on the irradiation face; a homogenization component for homogenizing beam intensity on the irradiation face. The homogenization component includes an optical delay component which makes a delay of the adjacent divided beams longer than an interference distance of the time of the laser beam, a light rotation component which makes polarization directions of the adjacent divided beams actual orthogonal.

Description

The optical system of laser beam uniform irradiation

Technical field

When the present invention relates to shone thing laser treatment (laser treatment), improved the optical system that the inhomogeneity laser beam uniform irradiation of the intensity distributions of the illuminating laser beam on the shadow surface (laser beam) is used.

Background technology

As the heat treated example that has used laser radiation, we know when making polysilicon film, vapor deposition (vapor deposition) method that goes up by CVD (Chemical Vapor Deposition) method (CVD) etc. at suitable substrate (for example glass substrate) forms non-crystal silicon fiml in advance, carries out the method for polycrystallization with this amorphous silicon film of laser beam flying.U.S. Pat P5 for example, 529,951 disclose in the assembling of SIC (semiconductor integrated circuit), to circuit component part evaporation amorphous silicon, to the place of necessity irradiation excimers (excimer) laser beam, form non-crystal method by again on polysilicon layer.This United States Patent (USP) uses fly lens or prism as the homogenising means in optical system in order to increase the shadow surface zone, makes intensity distributions homogenising in whole subquadrate zone of excimer laser bundle.

We also know the method that makes the silicon fiml polycrystallization on large-area substrate, for example scioptics shine the laser beam condensation from LASER Light Source on amorphous silicon film, when irradiation, laser spots is scanned on silicon fiml, make on one side its fusing partly, in the process of solidifying make silicon crystallization on one side.In the laser beam of using, depend on the beam profile of lasing light emitter in the axial intensity distribution of the light beam of irradiation position, be axisymmetric Gaussian distribution normally to optic axis.The polysilicon film that the irradiation of the light beam by such distribution forms is very low to the homogeneity of the crystallization of surface direction, is difficult in the film crystal pipe manufacturer it is used as Semiconductor substrate.

In addition, know that also making the short beam profile of excimer laser on shadow surface of wavelength is rectangle, skims over the technology that heats on the semiconductor film.In open 11-16851 of Jap.P. and the open 10-333077 of Jap.P., after passing through two cylindrical lens arrays intersected with each other in face perpendicular to optical axis from the laser beam of oscillator, by being configured in the condenser lens in its place ahead, imaging on the semiconductor film surface.Cylindrical lens array is configured to a plurality of small cylindrical lenses parallel to each other, and perpendicular to optical axis, is the optical element that a light beam is divided into many light beams.

Method recited above makes the laser beam that adopts Gaussian distribution or simple pattern by two cylindrical lens arrays, becomes uniform intensity distributions on the both direction of quadrature.The shape of illumination beam on the irradiating surface of semiconductor film etc. has different width on the both direction of quadrature on the semiconductor surface.This method moves in a narrow side's Width scanning by the laser beam that makes irradiation, has been concatenated to form the certain many crystal regions of width with the width that is equivalent to a long side on semiconductor film.

; if cut apart laser beam from LASER Light Source by such cylindrical lens array, synthetic on shadow surface again, the then lasing interference of light on the shadow surface; at irradiation position, formation has the interference figure that beam intensity is high and repeat back and forth in the low place of beam intensity.

Because by the growth of a plurality of light beams that overlapped in the crystallization to the shadow surface of the interference effect that produces on the shadow surface.Promptly, illumination beam on using shadow surface be shaped as rectangular illuminating laser beam heat the non-crystalline semiconductor film, when making its crystallization, because illumination beam is moved at narrow Width, so have a strong impact on the growth of crystallization with the intensity distributions of the length direction of moving direction quadrature, the intensity distributions of this direction is inhomogeneous, interference figure is big, and this grows up for the crystal grain that makes silicon fiml is disadvantageous.

Several removing because the method for the unevenness of the laser radiation intensity that this interference causes proposed.Disclosing by parallel light tube (collimator) in the open 2001-127003 of Jap.P. makes the laser beam from light source become directional light, shining reflecting surface is on the stair-stepping mirror, make the light beam of cutting apart by this multistage mirror by synthetic cylindrical lens array and the cylindrical lens array that converges usefulness, shine on the shadow surface.This optical system is by the ladder between each reflecting surface, for the light beam of cutting apart is provided with the optical path difference longer than interfered with the length of laser beam, prevents the interference between the light beam cut apart in the shadow surface.

In addition, Jap.P. is open disclose for 2001-244213 number make laser beam from light source become directional light by beam collimator after, shine on a plurality of little catoptrons, reflected light from each catoptron is shone on the shadow surface, make its coincidence, so by guaranteeing that optical path difference through the laser beam of each flat mirror reflects interfering more than the length, has prevented interference equally.

The catoptron that the homogenization technology utilization of light beam recited above has a plurality of reflectings surface is provided with optical path difference, prevents because of cutting apart laser beam from same light source, and the interference that takes place when on shadow surface, overlapping, but these optical systems need special catoptron.The particularly special optical system of opening 2001-244213 need make the configuration based on the optical axis bending of the optical system of catoptron.In order to make a plurality of each light beam of cutting apart correctly shine shadow surface, require each catoptron of optical system to satisfy the configuration that certain location concerns.Therefore, it is complicated that the configuration of a plurality of catoptrons becomes, the problem that the degree of freedom of the optical system that existence should be disposed as annealing device reduces.Particularly to whole when cutting apart bundle optical path difference being set, for the big laser generation source of the interference distance of time, it is not only big but also complicate that device becomes, and this is unpractical, and the optics adjustment is also difficult.

Summary of the invention

In view of problem recited above, the object of the present invention is to provide a kind of optical system of laser beam uniform irradiation, this optical system is by making each light beam illumination beam that formation has uniform intensity distributions on shadow surface overlapping on the shadow surface of having cut apart from the laser beam of light source, it can prevent to overlap the interference of cutting apart interfascicular that causes, the homogenising that can seek illumination beam.

Another object of the present invention is to provide a kind of optical system of uniform irradiation, be used in and prevent such interference, make the structure of illumination beam homogenising and adjustment to become simple and easy.

Other purpose of the present invention is to provide a kind of optical system, and it is applicable to the laser heating device that makes its polycrystallization in the amorphous silicon film as shone thing, can be manufactured on the few polysilicon film of lattice imperfection on the crystal region.

The optical system of uniform irradiation laser beam of the present invention comprises: from the laser beam of LASER Light Source in beam cross section, spatially be divided into the laser beam partition member of cutting apart bundle; And be radiated at coincidence irradiation part on the shadow surface cutting apart Shu Chonghe; It is characterized in that: described laser beam partition member is waveguide or cylindrical lens array, described coincidence irradiation part comprises replica lens, and described laser wants partition member to be arranged on the upstream side of described coincidence irradiation part, make the described width of cutting apart bundle greater than, equal 1/2 times of space interference distance of the cross-wise direction of lasing aperture.On shadow surface, overlap by overlapping irradiation part even have the bundle of cutting apart of width of light beam, also alleviated the mutual interference of a plurality of light beams, make being evenly distributed of exposure intensity on the shadow surface.

The optical system of this laser beam uniform irradiation spatially is divided into a laser beam partition member and a light beam of cutting apart of cutting apart bundle to the laser beam from LASER Light Source and overlaps the coincidence irradiation part that is radiated on the shadow surface in being included in beam cross section, also comprise the uniform homogenising parts of the beam intensity that makes on the shadow surface.A kind of described homogenising parts comprise make the described light beam of cutting apart adjacent one another are adjacent and cut apart an intrafascicular side and postponed the also long optical delay components of interference distance than the time of this laser beam with respect to the opposing party, be used to prevent that adjacent divided interfascicular from interfering on shadow surface, make being evenly distributed of exposure intensity.

As other homogenising parts of the present invention, comprise: the polarization angle that makes the adjacent divided interfascicular of being cut apart by the laser beam partition member is the optically-active parts of quadrature in fact.The optically-active parts make each adjacent interference of cutting apart interfascicular that can produce when cutting apart Shu Chonghe by making the polarization angle between the light beam of having cut apart orthogonal, alleviating on the shadow surface, make being evenly distributed of exposure intensity.

The key element of the interference distance of the key element of the interference distance in the space of the cross-wise direction of optical system of the present invention by reducing described laser beam simultaneously and the time of optical axis direction has and can make the exposure intensity extremely advantage of uniform that distributes.

Among the present invention, overlap irradiation part and comprise: make the displacement or stagger each other each other on shadow surface of the laser beam respectively cut apart, form the illumination beam that duplicates.Be divided into a plurality of bundles of respectively cutting apart when overlapping irradiation part by partition member, optically stagger, shine on the shadow surface, reduced the interference of cutting apart interfascicular on the shadow surface.The coincidence irradiation part that is used to make this duplicate displacement or staggers can be implemented simply, can use the parts of the interference that the key element of interference distance of the time of the key element of the interference distance that prevents described space and optical axis direction causes simultaneously.

The optical system of described laser beam uniform irradiation of the present invention as the noncrystal or multicrystal semiconductor film that is formed on the substrate, can be annealed shadow surface as semiconductor film and use optical system.

Description of drawings

Following brief description accompanying drawing.

Figure 1A and 1B are the figure of configuration of optical system of the laser beam uniform irradiation of the expression embodiment that utilized waveguide of the present invention, represent figure that observes from the y direction and the figure that observes from the x direction respectively.

Fig. 2 is the cut-open view of cutting apart form of the laser beam of explanation waveguide.

When Fig. 3 A represents that laser beam is cut apart in waveguide, the configuration of cutting apart bundle in the cross section of the laser beam that should cut apart, Fig. 3 B represents the configuration of cutting apart bundle in the waveguide outgoing end face.

The intensity distributions of Fig. 4 two synthetic illumination beams when cutting apart bundle and on shadow surface, overlapping adjacent one another are that to be expression be partitioned into by waveguide and the figure (during d=s) of visibility.

Fig. 5 is the figure of definition of interference distance s in the space of explanation laser beam.

Fig. 6 is the intensity distributions of the synthetic illumination beam of expression when being divided into cutting apart bundle and overlapping of 7 bundles by waveguide on shadow surface and the figure (during d=s) of visibility.

Fig. 7 is the curve map of the relation of expression optical path difference of laser beam and visibility.

Fig. 8 A and Fig. 8 B are that with Figure 1A with Figure 1B suitable figure of cylindrical lens array as the configuration of the optical system of the laser beam uniform irradiation of other embodiment of laser beam partition member of the present invention used in expression.

Fig. 9 A represents to use cuts apart the usefulness cylindrical lens array as the laser beam partition member, the configuration of cutting apart bundle in the cross section of the laser beam that should cut apart, and Fig. 9 B represents the configuration of cutting apart bundle in the waveguide outgoing end face equally.

Figure 10 is expression by the intensity distributions of cutting apart two synthetic illumination beams when cutting apart bundle and overlapping adjacent one another are of cutting apart with cylindrical lens array on shadow surface and the figure (during d=s) of visibility.

Figure 11 is expression by the intensity distributions of cutting apart the synthetic illumination beam when being divided into cutting apart bundle and overlapping of 7 bundles with cylindrical lens array on shadow surface and the figure (during d=s) of visibility.

It is relevant with embodiments of the invention that Figure 12 A and 12B represent, uses waveguide as partition member, the retardation plate 7 that has utilized light transmission as the optical system of the laser beam uniform irradiation of optical delay components with Figure 1A and the same figure of Figure 1B.

Figure 13 is the variation of optical system shown in Figure 12, and the optical system and the same figure of Figure 12 B of the form of cutting apart bundle that does not reflect and pass through have been interdicted in expression between the reflecting surface of waveguide.

Figure 14 is the figure same with Figure 12 B of configuration of optical system of the laser beam uniform irradiation of expression other embodiment of the present invention, the optical axis of expression incident light and the configuration of waveguide core axle oblique.

Figure 15 is the figure same with Figure 14 that the light beam in the configuration of expression optical axis of incident light and waveguide core axle oblique is cut apart.

Figure 16 A and 16B be the explanation oblique cutting state that disposed the laser beam in the waveguide shown in Figure 15 of the optical axis of incident light and waveguide core axle with Fig. 3 A and the same figure of Fig. 3 B.

Figure 17 is the figure of configuration of optical system of the laser beam uniform irradiation of expression other embodiment of the present invention, and it is configured to the plane of incidence and the waveguide core axle oblique of waveguide.

Figure 18 A and 18B represent the optical system about the laser beam uniform irradiation of other embodiment of the present invention, the cylindrical lens array of cutting apart usefulness has been used retardation plate with Fig. 8 A and the same figure of Fig. 8 B.

Figure 19 is illustrated in and duplicates the figure same with Figure 18 B that has disposed two retardation plates with the front and back of cylindrical lens array.

Figure 20 is the figure same with Figure 18 B that carries out focal spot modulation with cylindrical lens array to duplicating.

Figure 21 A and Figure 21 B represent the optical system about the laser beam uniform irradiation of other embodiment of the present invention, and the use waveguide as partition member, use optically-active plate as the homogenising examples of members, is respectively and Figure 1A and the same figure of Figure 1B.

Figure 22 is the variation of the optical system of Figure 21 B, and the figure same with Figure 21 B of the optical system of the form of cutting apart bundle that does not reflect and pass through interdicted in expression between the reflecting surface of waveguide.

Figure 23 is configuration and same figure Figure 21 B of optical system of the laser beam uniform irradiation of expression other embodiment of the present invention, the optical axis of expression incident light and the configuration of waveguide core axle oblique.

Figure 24 is the figure same with Figure 23 that the light beam in the configuration of expression optical axis of incident light and waveguide core axle oblique is cut apart.

Figure 25 is the variation of Figure 21, and expression comprises the optical system of the laser beam uniform irradiation of half-wave plate and optical length compensating unit.

Figure 26 is the variation of the example of Figure 23, and expression comprises the optical system of the laser beam uniform irradiation of half-wave plate and optical length compensating unit.

Figure 27 A and 27B represented to use cut apart with cylindrical lens array and half-wave plate with Figure 1A and the same figure of Figure 1B.

Figure 28 represents having cut apart the bundle alternate configurations figure same with Figure 27 B of optical system of half-wave plate and retardation plate shown in Figure 27 A and the 27B.

Figure 29 is illustrated in and duplicates the figure same with Figure 27 B that has disposed two retardation plates with the front and back of cylindrical lens array.

Figure 30 A and 30B are about other embodiment of the present invention, expression coincidence irradiation part makes respectively cuts apart bundle displacement each other on shadow surface, the figure of the configuration of the optical system of the laser beam uniform irradiation that promptly staggers, duplicates represents respectively from the figure of y direction observation and the figure that observes from the x direction.Figure 30 C is the figure of profile of the illumination beam intensity of the optical system shown in presentation graphs 30A and the 30B.

Figure 31 A, 31B and 31C represent the optical axis of incident light and the configuration of waveguide core axle oblique respectively with Figure 30 A, 30B and the same figure of 30C.

Figure 32 A and 32B be have on shadow surface, make the coincidence irradiation part cutting apart beam displacement, duplicate respectively with Fig. 8 A and the same figure of Fig. 8 B.

Figure 33 A and 33B be have on shadow surface, make the coincidence irradiation part cutting apart beam displacement, duplicate respectively with Figure 18 A and the same figure of Figure 18 B.

Figure 34 has the figure same with Figure 27 that makes the coincidence irradiation part of respectively cutting apart beam displacement, duplicating on shadow surface.

Embodiment

The laser beam partition member of optical system of the present invention makes that the single laser beam sent from LASER Light Source is partitioned into, and a plurality of bundles of cutting apart are cut apart bundle and are overlapped and shine on the shadow surface by overlapping parts, making.Here the laser beam partition member is about a plurality of bundles of cutting apart, making each width of light beam is more than 1/2 times of interference distance in the space of the cross-wise direction on the lasing aperture, in view of the above, prevent the interference of cutting apart interfascicular on shadow surface, the intensity distributions of illumination beam can homogenising.

Before light beam was cut apart, two cut apart bundle when being adjacent one another are in the cross section of this laser beam, cut apart the interference of interfascicular easily, but respectively cut apart more than 1/2 times of interference distance that beam width is the space by making, and just can reduce mutual interference.

The above-mentioned width of light beam of respectively cutting apart bundle is defined as the width of cutting apart bundle in the exit facet of laser beam partition member, the interference distance of this time space is meant when the laser beam from light source projects the position of this exit facet, the interference distance in the space in the cross section.The back will be described in detail, and the interference distance in this space is meant that laser beam is divided into two, then because the interference that takes place when on shadow surface, overlapping once more, and the minimum overlay distance of two light beams of the visibility of describing later (visibility) when becoming 1/e.

In the present invention, the ratio of interference distance of cutting apart the space of the cross-wise direction in beam width and the beam cross section is more than 1/2, still More than better, 1 or more better.That is, the width of being cut apart by the laser beam partition member of cutting apart bundle wishes to be set at the interference distance in space

More than, particularly more than 1 times.

The upper limit of cutting apart beam width is determined by the number of cutting apart of cutting apart laser beam, but the quantity of the light beam of cutting apart is 5 at least, wishes more than 7.Although it is just effective more to cut apart the planarization of the big more intensity of laser beam to irradiation of number, do not wish to cut apart that number is big is lower than 1/2 to the described ratio of cutting apart beam width and the interference distance in space is become.Practical to cut apart number be 5～7, cuts apart beam width and be set at more than 1 times for the interference distance in space.

The laser beam partition member cuts apart to come the laser beam of self-excitation light source, and stipulates described laser beam width, but this partition member can use waveguide or cylindrical lens array.They all are only to be divided into described several bundle of cutting apart of cutting apart perpendicular to any one the steering handle laser beam in the face of optical axis.

Waveguide can utilize ducted body with reflecting surface respect to one another and solid light penetrating object.The waveguide of hollow can utilize the object that in the space two minute surfaces is disposed at certain intervals relatively.

Solid waveguide is transparent tabular, and two sides' interarea as minute surface, is used for two sides' end face the light penetrating object of incident and outgoing.Such waveguide can utilize optical flat usually.

In waveguide, in the laser beam partition member, comprise the outgoing laser beam that is used to make self-excitation light source and incide collector lens between reflecting surface in the waveguide.

Can obtain from the exit facet of waveguide: do not reflect and see through the bundle of cutting apart in the waveguide at reflecting surface; The bundle of cutting apart with two groups that on relative reflecting surface, reflect at every turn.Incident beam in the every increase of number of times of reflecting surface reflection once, cutting apart bundle just increases by two.

And be that to make column, cross section be that a plurality of cylindrical lenses of lens-shaped are arranged in parallel within and optical axis in fact on the direction of quadrature as the cylindrical lens array of laser beam partition member.Can cut apart bundle corresponding to what each small cylindrical lens obtained.In the laser beam partition member that uses cylindrical lens array, wish to comprise parallel light tube to cylindrical lens array incident directional light.

Other forms of optical system of the present invention comprise the homogenising parts in optical system, comprise optical delay components and optically-active parts in the homogenising parts.

In the present invention, optical delay components have make adjacent divided bundle in the light beam of cutting apart by described laser beam partition member a side with respect to the opposing party, the function that the interference distance of the time of this laser beam of retardation ratio is also long, in view of the above, on shadow surface, reduce and even prevent interference between the adjacent divided bundle.

Optical delay components is preferably utilized and is postponed the light penetrating object that light beam is used, i.e. retardation plate was inserted into by respectively cutting apart in the light path that bundle spatially separates each other that described laser beam partition member is cut apart.At this moment,, insert retardation plate in the adjacent divided intrafascicular at least any one party, optical path difference optically is set between adjacent divided bundle respectively cutting apart bundle conversely to the time from the single laser beam projection of light source.

The optical path difference that retardation plate makes the adjacent light beam of cutting apart is bigger than the interference distance of the time of this laser beam, and in view of the above, what prevent to separate a plurality ofly cuts apart that bundle shines shadow surface, the interference of cutting apart interfascicular when it is overlapped.Optical path difference is that the difference that light beam sees through the refractive index of the refractive index of length, retardation plate and air decides by the thickness of retardation plate.

Since the laser beam of self-excitation light source be benchmark, retardation plate insert from this laser beam isolated adjacent cut apart bundle every one arrangement, produce optical path difference each other, thereby produce phase differential.

Among the present invention, the homogenising parts also comprise the optically-active parts, the optically-active parts make the adjacent polarization angle of cutting apart interfascicular that is partitioned into by laser beam partition member quadrature in fact, overlap on shadow surface, form the illumination beam of the profile with needed uniform intensity distributions.In the present embodiment, by making the polarization angle between the light beam of cutting apart orthogonal, reduce, make being evenly distributed of exposure intensity when each adjacent interference of cutting apart interfascicular that can produce when cutting apart Shu Chonghe on shadow surface.

Since the laser beam of self-excitation light source be benchmark, the optically-active plate insert from this laser beam isolated adjacent cut apart bundle every one arrangement, make between plane of polarization, to produce about 90 ° angle each other.

An example of optically-active parts is to use quartzy crystallization plates, and the plane of polarization that this crystallization plates makes the light beam that sees through is with respect to almost 90 ° of the optically-actives of the opposing party's the plane of polarization of cutting apart bundle.Such optically-active parts are called half-wave plate.Here, so-called quadrature in fact, comprise from a side the plane of polarization of cutting apart bundle and the opposing party cut apart the plane of polarization quadrature of bundle the time angle have ± 30 ° skew is good.Like this, even the plane of polarization of two light beams is non-orthogonal, but oblique also can reduce the substantial interference between two light beams.

Other optically-active parts can also utilize Fresnel rhombohedron (fresnel rhomb).

In addition, because only at an adjacent divided intrafascicular described side's the intrafascicular insertion optically-active parts of cutting apart, the bundle of cutting apart with respect to the opposing party produces optical path difference thus, this light path official post produces the skew that these cut apart the image space of bundle on shadow surface.Therefore, at cutting apart of described the opposing party of intrafascicular insertion optical length compensating plate, wish to make the opposing party's who does not insert described optically-active parts the optical length of cutting apart bundle identical in fact with this side's the optical length of cutting apart bundle.In view of the above, described side on the shadow surface and the opposing party's the imaging distinctness of cutting apart bundle can be made, the homogenising of the illumination beam intensity distributions of synthesizing can be helped.

About the configuration that is retardation plate and optically-active plate of described homogenising parts, overlapping irradiation part comprises copying to duplicating on the shadow surface (as transmitting) lens from restrainting cutting apart of laser beam partition member, when having formed replica lens a plurality of when cutting apart regional that bundle spatially separated, the homogenising parts of retardation plate etc. are inserted in such separated region.For example when the laser beam partition member was waveguide, retardation plate was configured on the focal position of respectively cutting apart Shu Huiju by replica lens.

About the simplification of homogenising parts, wish the structure of waveguide or configuration do not produce do not reflect and pass through cut apart bundle.This configuration as described later, by predetermined group cut apart single retardation plate of intrafascicular insertion or optically-active plate, intrafascicularly do not insert in cutting apart of another group, can alleviate the interference on the shadow surface.It has the easy advantage of configuration that can make single optical delay components.

For this reason, only wish not reflect and by cutting apart of waveguide of intrafascicular insertion baffle in interior reflective surface at incoming laser beam.

Other form can adopt and make to the laser beam of the waveguide incident structure for the incident asymmetricly of waveguide core axle.Therefore, in the waveguide, make for the central shaft oblique between the reflecting surface of the optical axis of the incoming laser beam of waveguide and described waveguide, in view of the above, can not be created in do not reflect on which reflecting surface and pass through cut apart bundle.

Other form is used solid light penetrating object recited above in waveguide,, adopt the structure of the central shaft oblique of the plane of incidence of this waveguide and waveguide, can make the incident light refraction with the plane of incidence of oblique.Can make incident beam at least once, constitute and cut apart bundle in the reflecting surface reflection.In these forms, do not reflect the structure of just passing through of cutting apart bundle with blocking and compare, have and can in irradiation, utilize all advantages of cutting apart bundle.

When the laser beam partition member is cylindrical lens array, because the outgoing of each cylindrical lens array one sidelight road is separated from one another, so other configuration of homogenising parts can be configured in retardation plate or optically-active plate on the light path of light beam.At this moment, can several little retardation plates or optically-active plate be configured in the one-tenth row of cutting apart by cylindrical lens array light beam in one.

Like this, a plurality of parts of cutting apart bundle see through the homogenising parts, overlap irradiation part and are radiated on the shadow surface cutting apart Shu Chonghe, and the shape of the laser of irradiation is projected as rectangle or linearity, and the intensity distributions of the length direction of the light beam of irradiation becomes the same.

In the embodiments of the invention, overlap irradiation part and also comprise: on shadow surface, make and respectively cut apart laser beam and stagger each other, duplicate, form the function of illumination beam.Overlapping irradiation part is radiated at the Shu Chonghe of cutting apart that separates by partition member on the shadow surface, make it on shadow surface, become rectangle or linearity, but in the present embodiment, by several bundles of cutting apart are staggered at the length direction of the shape of illumination beam, particularly eliminated the strength distribution of the intensity that the both sides of length direction produce.Such coincidence irradiation part preferably can utilize the cylindrical lens with lens aberration.

The optical system of the laser beam uniform irradiation of these embodiment of the present invention is applicable to: be used for covers the amorphous silicon that forms or the film heat fused of polysilicon by CVD (Chemical Vapor Deposition) method etc. on glass substrate, carry out polycrystallization or make during the annealing (annealing) that grows into thicker crystallization installs.Here, annealing is not only the solid film irradiating laser, directly carries out crystallization or crystallization again, also comprises: with laser radiation solid film is temporarily melted, after the process of setting of molten film in make its crystallization.

In the present invention, lasing light emitter comprises solid state laser and semiconductor laser, and laser beam comprises the first-harmonic and the higher hamonic wave of Solid State Laser and semiconductor laser.Particularly working as shadow surface is the silicon semiconductor film, especially during amorphous silicon film, except the first-harmonic of the solid state laser of Nd:YAG laser instrument, Nd:YLF laser instrument, Yb:YAG laser instrument etc., wish to utilize second higher hamonic wave (2 times of ripples) or the 3rd higher hamonic wave (2 times of ripples) irradiation.When these higher hamonic waves were wavelength region may in 350～800nm, described amorphous film can moderately absorb light beam, heat fused efficiently.

Particularly use in the optical system in above-mentioned annealing, on silicon film surface, form the irradiating laser of the wire of thin wide cut shape, by with the light beam line orthogonal directions on scan, when illumination beam passes through, width scan silicon thin film with this light beam, evenly, heating hastily, when light beam is placed cooling by the back, can in process of setting, make its crystalline growth, the interference figure of light beam is few, and intensity distributions is even, so can make the shape of the length that each crystallization has wide cut and the crystal silicon film of high crystalline uniformly.

Embodiment 1

In embodiments of the invention 1, Figure 1A and Figure 1B represent the optical system of laser beam uniform irradiation, but represented this optical system on shadow surface, be formed on the y direction, converged example into the illumination profile of the linearity of wire in the x direction with uniform distributed expansion.

Optical system comprises laser beam partition member 3 and overlaps irradiation part 6 (61,62).In the present example, in laser beam partition member 3, utilize waveguide 4, laser beam 1 is divided into restraints 16a～16e cutting apart of requirement, these are cut apart bundle is imaged as the linearity profile on shadow surface 90 illumination beam 19 by overlapping irradiation part 6.

In the present embodiment, the laser beam 1 that is used to make from laser oscillator that comprises laser beam partition member 3 incides the optical system in the waveguide 4, comprise the extender lens 31, y direction collimation lens 32 and the x direction collimation lens 33 that are used to produce parallel beam, also be included in y direction optically focused below and make it incide the collector lens 34 of the cylindrical lens in the waveguide 4.

Parallel first type surface respect to one another has reflecting surface 41,42 in the waveguide 4, and reflecting surface 41,42 is vertical with the y direction in the figure.Laser beam 1 run through two between reflecting surface the plane of incidence 43 and the light shaft positive cross of exit facet 44 and laser beam.The laser beam 1 of incident is by being divided between the reflecting surface: from exit end penetrate cut apart Shu Chengfen, any one reflections of reflecting surface 41 and 42 once (m=1) two cut apart bundle (m=+1, m=-1) composition, two reflectings surface reflections twice (m=2) cut apart bundle (m=+2, m=-2) composition, reflect a pair of each composition of cutting apart bundle from the exit end ejaculation more than three times and even three times respectively in addition.

Come the bundle of cutting apart of self-waveguide 4 to project on the shadow surface 90 by overlapping irradiation part 6 coincidences.Overlapping irradiation part 6 copies to the y direction replica lens 61 (cylindrical lens) on the shadow surface and constitutes at the collector lens 62 (cylindrical lens) of x direction optically focused by cut apart bundle at the y steering handle.The replica lens 61 of y direction is by x direction collector lens 62, on shadow surface 90, light beam is extended the length of regulation in the y direction, x direction collector lens 62 makes light beam converge in the x direction to be wire, in view of the above, to have obtained the illumination beam 19 of linearity profile on shadow surface.

More specifically, Fig. 2 represented to use the laser beam partition member waveguide, cut apart the form of the laser beam that penetrates from laser oscillator (not shown), but from the laser beam of laser oscillator collector lens 34, through focal point F by cylindrical lens ₀Incide in the waveguide 4.In waveguide 4, the part of incident beam does not have not what the reflecting surface reflection just saw through cuts apart bundle (order of reflection=0), reflected the bundle of cutting apart once reflecting surface 41 respect to one another or 42 and 2 kinds (m=± 1) have been arranged in the y direction, in the y direction 2 kinds (m=± 2) are arranged too at reflecting surface 41 and 42 bundles of cutting apart that reflect twice, respectively cut apart bundle and penetrate from exit facet 44.Perpendicular to optical axis and comprise focal point F ₀Face on, the virtual image focal point F of respectively cutting apart bundle that penetrates from exit facet 44 is arranged _{+ 1}, F _-1, F _{+ 2}, F _-2, can observe and respectively cut apart bundle from these virtual image focal point F _{+ 1}.... the opening through exit facet 44 is penetrated.

In Fig. 2, if the collector lens 34 of supposition when not having waveguide, the profile of light beam that the laser beam of expanding by focus projects to the face at exit facet 44 places is circle, and the laser beam 14 of this projection can be decomposed into and a plurality of bundle corresponding compositions of classifying respectively of cutting apart.Each composition in the cross section of laser beam 1 is on the cross section, if the y direction by m=-2 ,-1,0 ,+1 ,+2 order cuts apart, then should be noted that the composition that penetrates from the exit facet 44 of waveguide 4 promptly cut apart bundle the y direction be order of reflection=+ 2 ,+arrangement of 1,0 ,-1 ,-2 order.

In Fig. 2, the m=0 that has only represented to penetrate from the exit facet 44 of waveguide 4 ,+1 ,+configuration of cutting apart bundle of 2 composition, the bundle of cutting apart of m=+1 and m=+2 penetrates for the opposite towards each other direction of the median surface of reflecting surface.And m=-1 ,-2 cut apart bundle for m=+1 ,+central plane of 2 reflecting surface is positioned at symmetry direction, but omitted in the drawings.

Fig. 3 A is from focal point F laser beam ₀Do not reflect in waveguide 4, project to the figure of cutting apart the width graphic of cutting apart bundle of the laser beam 14 on the corresponding flat of exit facet 44 of waveguide 4.It is that the laser beam 14 of following the circular contour of Gaussian distribution is divided into 7 examples of restrainting by waveguide.

In waveguide 4, overlapping repeatedly on the adjacent divided Shu Zaiqi exit facet 44.Therefore, based on cutting apart of laser beam 1 and the boudary portion of composition adjacent one another are in Fig. 3 B, consistent with the part repeatedly of cutting apart bundle of the exit facet of waveguide.For example, in Fig. 3 A, the boundary portion iii overlapping repeatedly in the exit facet 44 of waveguide (shown in Fig. 3 B) of the boundary portion III of the composition of m=+1 and the m=0 that is close to it.

If such bundle of cutting apart repeatedly passes through y direction replica lens 61 and x direction collector lens 62, coincidence projects on the shadow surface 90, then interferes in the illumination beam on shadow surface, and intensity has formed wavy distribution.

Fig. 4 has represented from two compositions cutting apart bundle, for example two of order of reflection m=+1 and m=0 compositions overlap the example of the intensity distribution of the illumination beam 19 on the shadow surface 90 when shining on the shadow surface 90 by y direction replica lens 61 and x direction collector lens 62 etc.But adjacent divided bundle boundary portion iii and III seriously interfere with each other on original laser beam, and same on original laser beam away from each other cut apart bundle boundary portion IV and ii showed and interfere the change of the intensity distributions that causes little.In Fig. 4, on transverse axis, get and cut apart width d, on the longitudinal axis, get relative beam intensity.Just, Fig. 4 distributes intensity of laser beam to be approximately Gaussian distribution, the situation when cutting apart width d and equating with the interference distance s in space.

The degree of the interference that the coincidence on the shadow surface causes depends on the ratio of the interference distance s of the laser beam space of cutting apart width d and this position.Here, the interference distance s in space is defined as when the intensity distributions of the beam cross section of laser beam keeps Gaussian distribution, as shown in Figure 5, regulation beam diameter D is that intensity becomes optical axis intensity 1/e ²Circle (1/e when (here, e is the end of natural logarithm) ²Circle) diameter D is the 1/e of the both sides when single laser beam is branched into two ²At this moment in the heart distance in the circle is the state that makes its interference after public from make their optical axises at shadow surface, and optical axis is staggered each other, and in overlapping irradiation area, the visibility of interference fringe is reduced to 1/e.Here, visibility be the difference of the maximum intensity of the intensity distributions after interfering and minimum intensity divided by maximum intensity and minimum intensity and and the value that obtains is the yardstick of the expression degree of interfering.

When the cutting apart width d and be d=s/2 of laser beam, in the lap of the illumination beam in the approximating zone of adjacent divided bundle, visibility is near 1, away from the lap of illumination beam in zone in visibility be 1/e.In the middle zone, reduce gradually from 1 to 1/e.In preferred embodiment, cutting apart width d is more than the d=s/2, and at this moment visibility is reduced to below the 1/e in the lap of the illumination beam in away from zone.

The width d of cutting apart of laser beam is When above, away from the lap of illumination beam in zone in visibility be reduced to 1/e ²In illustrated embodiments, away from the lap of illumination beam in zone in visibility be reduced to 1/e ⁴Below.

Make that to cut apart width d be d=s, as shown in Figure 2, by waveguide 4 laser beam is divided into 7 bundles, Fig. 6 expresses the intensity distributions when overlapping on shadow surface, showed the intensity distributions of quite being improved.In the figure, the period T of the interference fringe of generation is by T=λ/sin Δ θ decision.Here, λ is a wavelength, and Δ θ is that two of generation interference are cut apart the poor of the incident angle of bundle on shadow surface 19.

Embodiment 2

In the present embodiment, utilize cylindrical lens array as another kind of light beam partition member.Originally for example shown in Fig. 8 A and the 8B, the optical system of laser beam uniform irradiation comprises and is used to make the optical system that incides cylindrical lens array 5 from the laser beam 1 of laser oscillator, comprise the extender lens 31, y direction collimation lens 32 and the x direction collimation lens 33 that are used to produce parallel beam, come the parallel beam of self-focus lens 33 to incide cylindrical lens array 5.

In cylindrical lens array 5, cylindrical lens refers to x direction in the drawings and is column, towards optical axis the cross section convex lens is layered in the lens of y direction, but legend is made of 5 grades of so small cylindrical lens 5a～5e, in view of the above, has formed five and has cut apart bundle.

Incide other the duplicating that is configured in the place ahead from the bundle 15a～15e of cutting apart of cutting apart the cylindrical lens array 5 that light beam uses with cylindrical lens array 51 to the y direction, come self-replication to project on the shadow surface 90 by collector lens 62 (cylindrical lens), form and to have illumination beam 19 even in the y direction, that converge very carefully the wire profile in the x direction at x direction optically focused with the bundle of cutting apart of cylindrical lens array 51.Object lens 63 are configured in and duplicate with between cylindrical lens array 51 and the collector lens 62.

Fig. 9 A and 9B represented cylindrical lens array 5 laser beam cut apart form.With foregoing different cutting apart of being undertaken by waveguide, when the light beam of cutting apart with each small cylindrical lens overlaps on shadow surface, do not return, just superimposed, therefore, even two adjacent bundles of cutting apart overlap on shadow surface by duplicating with cylindrical lens array 51 and x direction collector lens 62, the intensity distributions after synthesizing does not have difference yet in the interference of y direction.

When Figure 10 represents to cut apart width d and equates with the interference distance s in above-mentioned space, two intensity distributions of cutting apart the coincidence of bundle on shadow surface adjacent one another are are certain in the y direction, its visibility is certain, is 1/e.

Figure 11 represents that cutting apart width d is d=s about be divided into the bundle of cutting apart of 7 bundles by the described cylindrical lens array 5 of cutting apart usefulness, the intensity distributions when on shadow surface, overlapping, but the y direction has showed goodish distribution.

Embodiment 3

Homogenising parts described in the optical system of present embodiment comprise optical delay components, and this optical delay components makes the either party of cutting apart intrafascicular adjacent divided bundle who is formed by described waveguide also long with respect to the interference distance of the time of this laser beam of the opposing party's retardation ratio.Cut apart between the bundle for two that send for the zone adjacent one another are that prevents laser beam and interfere, optical delay components is cut apart the optical path difference more than the interference distance of the time that is provided with between the bundle two of zone adjacent one another are.

Present embodiment has provided the retardation plate 7 that the utilized light transmission optical system as optical delay components.Shown in Figure 12 A and Figure 12 B, optical system has been used: utilized the laser beam partition member 3 of waveguide 4, as two cylindrical lenses (61,62) of the quadrature that overlaps irradiation part 6, as the retardation plate 7 of optical delay components.In this example, waveguide 4 is same with the waveguide of embodiment 1, cuts apart bundle 16a～16e to what laser beam 1 was divided into requirement, by overlap irradiation part 6 these cut apart bundle on shadow surface 90 as the illumination beam 19 of linearity profile and imaging.

In Figure 12 B, in a plurality of bundle positions separated from one another of cutting apart, be easy to generate the cutting apart in any one of bundle of interference each other, the retardation plate 7 (being optical flat 2) that inserts light transmission forms optical path difference as optical delay components in adjacent cutting apart between the bundle.In this example, the light beam of being cut apart by waveguide 4 is duplicated by y direction replica lens 61, on shadow surface, form illumination beam by x direction collector lens 62, but between y direction replica lens 61 and x direction collector lens 62, in each light beam, form focus f by y direction replica lens 61, glass plate as retardation plate 7 is inserted in focal position f in any one party of adjacent light beam or its front and back, optical path difference is set.In the example of figure, cut apart at 5 intrafascicular every the glass plate of an intrafascicular insertion as retardation plate 7, in the space between retardation plate adjacent one another are 7,7, other cut apart the bundle pass through.By the retardation plate 7 of such arrangement, overlap in the illumination beam on shadow surface, the interference that does not produce adjacent divided interfascicular is so can obtain the uniform profile of intensity distributions in fact.

The optical path difference Δ a of glass plate is by the thickness a of glass plate, the refractive index n of glass ₁, air refractive index n ₀(, common n ₀=1) provides.Δa＝(n ₁-n ₀)/n ₁。

The optical path difference Δ a of glass plate is set at more than the interference distance Δ L of time.Be Δ a Δ L.And the interference distance of the time of laser beam is by Δ L=c Δ t λ ²/ Δ λ provides.Here, c is the light velocity, and Δ t can interfere the time, and Δ λ is the wavelength width (spectrum width) that laser has, and the Wavelength of Laser width is narrow more, and interference distance is long more.

For instance, in the Nd:YAG laser instrument, about the light beam of central wavelength lambda=1.06 μ m, so spectrum width Δ λ=0.12～0.30mm is interference distance Δ L=3.8～9.4mm of time.

Represented that in Fig. 7 two distances of cutting apart the visibility of bundle on shadow surface and the optical path difference of cutting apart the interfascicular setting that go out from the Region Segmentation adjacent one another are of laser beam (are optical path difference Δ relation a).When optical path difference was the interference distance Δ L of time, visibility dropped to 1/e, further increased by making from the optical path difference of cutting apart interfascicular, and visibility further reduces.

The thickness of glass a of the optical path difference more than the interference distance Δ L of time is provided adjacent divided interfascicular and provides from these relations.The thickness of retardation plate wishes to be set at the optical path difference more than 2 times that the interference distance Δ L of time is set by retardation plate, more wishes to be more than 4 times.For example, light source is described Nd:YAG laser instrument, when the retardation plate 7 to optical delay components has used quartzy (refractive index n ₁=1.46) time, be 3.8～9.4mm for the interference distance Δ L of time, quartz glass thickness a is 12～30mm.

Figure 13 is the variation of present embodiment 3, and expression is from the configuration of the optical system of x direction observation.Except the difference of the configuration of optical delay components 7, be the optical system of the laser beam uniform irradiation identical basically with the optical system of Figure 12 A and Figure 13 B, but this example interdicted between the reflecting surface of described waveguide, do not reflect and pass through cut apart bundle.

That is the light beam of the straight ahead during, from the order of reflection m=0 of the waveguide 4 shown in described Fig. 2, Fig. 3 A and Fig. 3 B is by baffle 79 blockings that are configured in the focal position f after the y direction replica lens.Because the light beam crested body 79 of the straight ahead of m=0 stops, does not arrive shadow surface, so it there is not contribution to interfering.Therefore, as optical delay components 7, only insert any one party of cutting apart bundle group (m=+1 ,-2) or (m=-1 ,+2) of balanced configuration, sets of beams the opposing party does not dispose optical delay components 7, in view of the above, alleviate the interference of cutting apart interfascicular on the shadow surface, and optical delay components 7 can be utilized the single retardation plate 7l of cutting apart the unified transmission of bundle group (m=+1 ,-2) that makes a side, for example glass plate or glass bar have the advantage that can simplify optical system.

The optical system of other variation comprises waveguide 4 and optical delay components 7, the laser beam partition member that constitutes by waveguide that only provides do not contain in waveguide 4, do not reflect and straight ahead cut apart bundle, all bundles of cutting apart are reflected once at least, and prevent that plural reflection from cutting apart the identical number of times of bundle reflection. as shown in figure 14, such laser beam partition member can adopt the optical axis of incident optical system of laser beam partition member with respect to the central shaft of the waveguide structure with given angle oblique configuration.

Shown in Figure 15, circle 16A and Figure 16 B, 1. the peripheral composition that is set at the light beam of the collector lens 34 that incides the cylindrical lens in the waveguide 4 incides the plane of incidence of waveguide 4, in the reflecting surface reflection once, and from the exit facet outgoing; From other beam components of collector lens 34 2., 3., 4. be reflected twice respectively, three times, four times, other compositions are reflected by more times, penetrate from exit facet.By exit facet one side of the light beam that penetrates, cuts apart, represent with the numeral 1～8 of order of reflection m at Figure 15.

In Figure 16 A and Figure 16 B, the coincidence of cutting apart bundle in the configuration of cutting apart bundle of the beam cross section in the plane on the exit facet 44 and the exit facet has been described.The order of order of reflection has been represented the order of the configuration of cutting apart bundle in the lasing aperture.Therefore, the bundle of cutting apart of the sequence difference 1 of order of reflection is interfered on shadow surface each other easily, so dispose the slow parts of retardation plate 7 as the space in any one party of cutting apart bundle of sequence difference 1.As shown in figure 14, the focus f position that is configured in y direction replica lens of this retardation plate, reflection even number number of times (for example, m=2,4,6) cut apart the cut apart Shu Qun of Shu Qun for odd number number of times (m=1,2,3), secund, so by reflection even number number of times m=2,4,6 cut apart the single retardation plate 72 of insertion among the Shu Quanti, can prevent the adjacent bundle interference each other of cutting apart simply.

In Figure 16 A and Figure 16 B, as described in the above embodiments, the width d of cutting apart bundle be set to greater than, equal the space interference distance s 1/2, wish 1/ More than, particularly greater than, equal 1 s.

Figure 17 represents not to be formed on other variation of cutting apart bundle of straight ahead in the waveguide 4.In this example, make the optical axis 40 of waveguide 4 consistent with the optical axis 30 of collector lens 34, but the plane of incidence 43 by making waveguide 4 not with light shaft positive cross, with suitable angle oblique, make incident beam 13 refractions on the plane of incidence 43 of oblique, also can obtain there is not 0 secondary reflection, and have 1 time, 2 times, 3 inferior reflections cut apart bundle.In the present example, by focus f position in y direction replica lens, even number secondary reflection (for example m=2,4,6) cut apart bundle or odd number secondary reflection (for example m=1,3,5) cut apart retardation plate 71 of intrafascicular concentrated insertion, the optical path difference of adjacent divided interfascicular just can be set.

Embodiment 4

The cylindrical lens array that present embodiment represents to use described embodiment 2 as partition member with described retardation plate as the optical delay components of cutting apart bundle that postpones to separate by this cylindrical lens array, prevent the example of interfering.

Among Figure 18 A and Figure 18 B, cutting apart bundle 15a～15e of being partitioned into inserting retardation plate 7 in the y direction as optical delay components from the cylindrical lens array 5 of cutting apart usefulness.Each retardation plate 7 of this example is inserted into every one cuts apart the cutting apart among bundle 15a, 15c, the 15d of bundle, does not insert in cutting apart among bundle 15b, the 15d of other.In view of the above, limited the interference on the adjacent divided interfascicular shadow surface 90 of (for example, cut apart between bundle 15a and the 15b, or cut apart bundle 15b and 15c), can make the intensity distributions homogenising of the interference that produces by the illumination beam that overlaps.

Figure 19 is the variation of the optical system of the laser beam uniform irradiation shown in Figure 18 A and the 18B, but the duplicating with the focal position in the place ahead of cylindrical lens array 51 of bundle and its place ahead of cutting apart of cutting apart the cylindrical lens array 5 of usefulness locates to dispose respectively a pair of retardation plate 73 and 74.In the present example, because disposed two retardation plates 73 and 74, be conjugate relation so can make the face that is replicated of retardation plate and duplicate surface in the front and back of duplicating with cylindrical lens array 51, in view of the above, have the advantage of the diffractive effect minimum that can make on the shadow surface.

Figure 20 is the variation of the optical system of the laser beam uniform irradiation shown in Figure 18 B, just, the duplicating with the micro lens 512 of cylindrical lens array 51 of bundle of cutting apart of having inserted retardation plate 7 is made as and has different focal lengths with the micro lens 511 with cylindrical lens array 51 of duplicating of cutting apart bundle that does not insert retardation plate 7, and it is the same that their imagings on shadow surface are become.By by cut apart with cylindrical lens array 5 on the y direction, arrange, cut apart obtain cut apart cutting apart intrafascicular insertion every one and adjusting the retardation plate 7 that optical length is used of bundle, for the bundle of cutting apart that does not insert retardation plate, produced the skew of focal position f, but the offset that comes compensate for focus f with the focal length that duplicates with each micro lens of cylindrical lens array 51, in view of the above, can make the intensity distributions homogenising of respectively cutting apart bundle of imaging on the shadow surface.

Embodiment 5

In the present embodiment, use the optically-active parts, prevent the interference of adjacent divided bundle on shadow surface, realize homogenising as the homogenising parts.This optical system represents to comprise waveguide as the laser beam partition member, as the cylindrical lens array that overlaps irradiation part with as the optical system of the laser beam uniform irradiation of the optically-active parts of homogenising parts.This optical system is formed on the shadow surface, with uniform distributed expansion, is the illumination profile of the wire linearity that converge in the x direction in the y direction.Laser beam partition member 3 utilizes waveguide 4, and laser beam is divided into the bundle of cutting apart of desired quantity, by overlapping irradiation part cutting apart bundle is imaged as linearity on shadow surface profile.

In the optical system of present embodiment, described homogenising parts comprise: make by described waveguide cutting apart of forming intrafascicularly adjacent one another are adjacently cutting apart intrafascicular any one party with respect to the opposing party, the angle of plane of polarization is the optically-active parts of quadrature in fact.These optically-active parts make from the plane of polarization of cutting apart bundle in zone adjacent one another are orthogonal, prevent to cut apart bundle interference each other.

The optically-active parts carry out optically-active, and the relative angle that makes plane of polarization is quadrature in fact, thereby make two adjacent one another are to cut apart bundle and reach the degree that does not interfere in fact each other, wish to utilize the half-wave plate that is made of quartz.

In Figure 21 A and 21B, form focus f in the place ahead of the y direction replica lens 61 (cylindrical lens) in the place ahead of waveguide 4, half-wave plate 8 as the optically-active component configuration in this focal position.In the present example, it is intrafascicular to come five of self-waveguide 4 to cut apart, and only cuts apart intrafascicular insertion half-wave plate 7 order of reflection m=0, m=+2 and m=-2 three, does not intrafascicularly insert in cutting apart of other order of reflection of m=+1 and m=-1.This structure be arranged in the y direction cut apart bundle in one, insert half-wave plate.In view of the above,, only cut apart and insert half-wave plate 8 in the intrafascicular any one party, make its polarization angle with respect to restrainting quadrature in fact cutting apart of the opposing party at two adjacent one another are with reference to Fig. 2 and Fig. 3 A.In view of the above, cut apart intrafascicularly two of combination in any adjacent one another are,, also can not interfere even on shadow surface 90, overlap.Therefore, with the described restriction of cutting apart width,, improved the homogeneity of illumination beam by the coincidence of the different light beam of plane of polarization in fact.

Present embodiment makes the bundle of cutting apart that is arranged in the y direction insert half-wave plate 8 in one as the homogenising parts, so be necessary between half- wave plate 8,8 gap to be set, make other cut apart bundle and sees through the configuration of this half-wave plate and construct some complexity.

In order to address this problem, in structure shown in Figure 22, the light beam of the straight ahead of the baffle 89 blocking order of reflection m=0 at the f place, focal position of outgoing one side by being configured in y direction replica lens 61 particularly.The light beam of the straight ahead of m=0 does not arrive shadow surface, so it there is not contribution to interfering.Therefore, as the optically-active parts, a half-wave plate 8 is inserted in any one party of cutting apart Shu Qun (m=+1 ,-2) or (m=-1 ,+2) for light beam (m=0) balanced configuration of straight ahead, the opposing party's the bundle group of cutting apart does not dispose the optically-active parts.In view of the above, alleviated and having cut apart bundle 19 to each other interference on the shadow surface 90, and optically-active parts 8 can utilize the half-wave plate 82 that bundle group (m=+1 ,-2) sees through together of cutting apart that makes a side, have the advantage that to simplify optical system.

Baffle 89 can utilize the solid that absorbs or make the laser beam reflection, and for example graphite, pottery, metal etc. also can be assembled into one baffle 89 and described single optically-active parts 82, are configured in the focal position f of y direction replica lens 61.

The described variation of Figure 22 has been interdicted by baffle 89 and has been restrainted m=0 cutting apart of center, but because the light beam m=1 at the center of blocking has sizable energy, so do not utilize it can cause decrease in efficiency, is uneconomic in this.

Therefore, in the next variation, the optical axis of incident laser is with respect to the central shaft oblique of 41,42 of waveguide and its reflectings surface, as described Figure 14～Figure 16 of embodiment 3 represented like that, be not created on 41,42 of reflectings surface do not reflect and pass through cut apart bundle.At this moment, destroyed with the symmetry of cutting apart bundle that order of reflection m divides, as shown in figure 23, the light beam of waveguide is cut apart the bundle (m=1) of cutting apart that is separated into from primary event and is reflected (in the present example to several, to 6 times (m=6)) cut apart bundle, prevent that plural reflection from cutting apart the identical number of times of bundle reflection.And as can be seen from Figure 23, odd number secondary reflection m=1,3,5 and even number secondary reflection m=2,4,6 to cut apart that bundle concentrates at focal position f be one group, so need not abandon utilizing the unreflected bundle (m=0) of cutting apart shown in Figure 22, use just energy easy configuration odd number secondary reflection m=1 of single optically-active parts 8,3,5 or even number secondary reflection m=2,4,6 cut apart bundle, as shown in figure 23, by being that the Shu Zuzhong of cutting apart of even number number of times inserts single optically-active parts 82 only in reflection, the plane of polarization that just can make adjacent divided bundle group is quadrature in fact, has to realize preventing the advantage that interferes with each other simply.

Other variation as described Figure 23, optical system shown in Figure 24 constitutes waveguide 4 by solid light penetrating object, form the plane of incidence 43 of this waveguide 4, make the central shaft of it and waveguide 4 non-orthogonal, but oblique suitably, laser beam 12 from the described collector lens 34 of described light source one side is incided on the oblique plane of incidence 43, and refraction.The result, the light beam of incident is reflected once between reflecting surface 41,42 at least, same with Figure 23, do not generate do not reflect and pass through cut apart bundle (m=0), can set the bundle of cutting apart that order of reflection increases again and again, at this moment be divided into the bundle of cutting apart of cutting apart bundle or odd number secondary reflection that has only the even number secondary reflection with single half-wave plate, can unify to make and restraint group's polarization cutting apart of these divisions.At this moment because with the optical axis of the coaxial configuration collector lens 34 of the central shaft of waveguide, so the Design for optical system assembling is easy, and can realize and the same effect of Figure 23.

In described embodiment, the optically-active parts are in described example, and the intrafascicular insertion half-wave plate of cutting apart adjacent prevents to interfere with each other.But half-wave plate has simultaneously prolonged this in fact cuts apart the optical length of bundle, so inserting cutting apart bundle and do not insert and producing the poor of optical length cutting apart of half-wave plate between the bundle of half-wave plate.Like this, if two kinds of optical length differences of cutting apart bundle, then the image space of the illumination beam on the shadow surface is offset each other, and it is not distinct that the beam intensity profiles on the shadow surface becomes, particularly during line taking shape profile, and the expansion of Width intensity distributions.Below, expression is inserted for this reason optical length compensating plate, is prevented to produce the example of optical path difference.

Figure 25 uses the waveguide shown in Figure 21 B to cut apart light beam, at the focal position f of y direction replica lens 61, as mentioned above, is cutting apart intrafascicular insertion half- wave plate 8,8 every one.This example to the opposing party of not inserting half-wave plate cut apart bundle insert prolong optical length retardation plate 83 as the optical length compensating unit.This example uses optical flat as retardation plate 83, and its thickness setting is to make the optical length that produces with being produced by half-wave plate identical.On shadow surface, do not produce these and cut apart interfascicular optical path difference each other, can guarantee the vividness of illumination profile.

Figure 26 is an example of having used retardation plate 83 in the example of Figure 23, focal position f in y direction replica lens 61, in cutting apart in bundle (m=2,4, the 6) group of even number secondary reflection, as mentioned above, the single half-wave plate 82 of unified insertion, do not insert single retardation plate 83 the cutting apart in bundle (m=1,3, the 5) group of odd number secondary reflection the opposing party, eliminated the optical path difference between the beam bundles.The special advantage of this example is to make single half-wave plate 82 and single retardation plate 83 integrated, is configured in the position of described focus f simply.

Embodiment 6

Present embodiment represent to use the optically-active parts as the homogenising parts, use the example of cylindrical lens array as the optical system of the laser beam uniform irradiation of laser beam partition member.

In Figure 27, illustrate and be used for making the optical system that incides cylindrical lens array 5 from the laser beam 1 of laser oscillator (not shown), this optical system comprises extender lens 31, y direction collimation lens 32 and the x direction collimation lens 33 that is used to produce parallel beam, comes the parallel beam of self-focus lens 33 to incide cylindrical lens array 5.Cylindrical lens array 5 refers to x direction in the drawings and is column, towards optical axis the cross section convex lens is layered in the lens of y direction, but is made of 5 grades of small cylindrical lens 5a～5e, in view of the above, has formed five and has cut apart bundle 15a～15e.

The bundle of cutting apart on the y direction from the cylindrical lens array 5 of cutting apart usefulness incides other the duplicating with cylindrical lens array 51 that is configured in its place ahead, the bundle of making by oneself with cylindrical lens array 51 of cutting apart projects on the shadow surface 90 by the collector lens 62 (cylindrical lens) at x direction optically focused, forms to have illumination beam 19 even in the y direction, that converge very carefully the wire profile in the x direction.Object lens 63 are configured in and duplicate with between cylindrical lens array 51 and the collector lens 62.

Half-wave plate 8 is inserted into from the cylindrical lens array 5 of cutting apart usefulness in cutting apart bundle 15a～15e that the y direction is cut apart as the optically-active parts, but half-wave plate 7 is inserted into every one cut apart and restraints among 15a, 15c, the 15d, does not insert in cutting apart among bundle 15b, the 15d of other.In view of the above, adjacent divided interfascicular (for example, is cut apart between bundle 15a and the 15b, cut apart bundle 15b and 15c or other adjacent cut apart interfascicular), polarization angle is quadrature in fact, has suppressed the interference on shadow surface 90, the intensity distributions homogenising that the interference of the illumination beam 19 of coincidence is produced.

Other variation has been expressed the example that half-wave plate also comprises the optical length compensating unit, Figure 28 is in the optical system shown in Figure 27 A and Figure 27 B, insert the example of the vitreum of retardation plate 83 in the bundle (15b, 15d in the present example) as the optical length compensating unit in cutting apart of the corresponding the opposing party who does not insert the optically-active parts.As mentioned above, a described side's the bundle of cutting apart has been configured half-wave plate 8 as the optically-active parts, cuts apart the optical length of bundle but the insertion of half-wave plate 8 has prolonged this.If two kinds cut apart next optical length difference, the image space on the shadow surface is skew each other just, and it is not distinct that profile becomes.In order to revise, the retardation plate 83 that prolongs optical length in cutting apart of the opposing party of intrafascicular insertion is the parts of optical length by way of compensation.This example is set at the optical flat of retardation plate 83 and produces and the identical thickness of optical length that is produced by half-wave plate 8.Because half-wave plate 8 and retardation plate 83 are alternately arranged in the configuration of Figure 27, so alternately and connect half-wave plate 8 and retardation plate 83 integratedly, can form the homogenising parts of one.

Figure 29 is duplicating with in the cylindrical lens array 51 in the optical system of laser beam uniform irradiation shown in Figure 27, the micro lens of cutting apart bundle 512 that has inserted half-wave plate 7 is made as with the micro lens of cutting apart bundle 511 that does not insert half-wave plate 7 has different focal lengths, it is the same that their imagings on shadow surface 90 are become.By by cut apart with cylindrical lens array 5 cut apart, be arranged in the y direction cut apart bundle cut apart the half-wave plate 8 that intrafascicular insertion rotatory polarization face is used every one, for the bundle of cutting apart that does not insert half-wave plate, produced the skew of focus f position, but this example skew of the focal length compensate for focus position of duplicating each micro lens of using cylindrical lens array 51, in view of the above, can make the intensity distributions homogenising of respectively cutting apart bundle of imaging on the shadow surface.

Embodiment 7

The optical system of Biao Shi laser beam irradiation overlaps irradiation and cuts apart the coincidence irradiation part of bundle and constitute by cutting apart from the laser beam partition member of the laser beam of LASER Light Source with on shadow surface in the present embodiment, overlapping irradiation part is duplicating on shadow surface when respectively cutting apart bundle, respectively cutting apart bundle staggers on shadow surface each other, i.e. displacement each other forms illumination beam.

Present embodiment utilizes waveguide to make the laser beam partition member, overlaps irradiation part the bundle of cutting apart from the laser beam partition member is shone on the shadow surface 90 with being offset each other, in view of the above, prevents to cut apart interfering with each other of bundle, the homogenising of seeking illumination beam on the shadow surface.

In the present embodiment, among Figure 30 A and Figure 30 B, the laser beam partition member comprises that the laser beam 1 that is used to make from laser oscillator incides the optical system in the waveguide 4, comprise the extender lens 31, y direction collimation lens 32 and the x direction collimation lens 33 that are used to produce parallel beam, also be included in optically focused on the y direction and make it incide the collector lens 34 of the cylindrical lens in the waveguide 4.

In the waveguide 4, parallel first type surface respect to one another has reflecting surface 41,42, and reflecting surface 41,42 is vertical with the y direction in the figure, the plane of incidence 43 and exit facet 44 and optic axis quadrature (parallel with the y direction).By Fig. 2 and 3 of described embodiment 1 as can be known, be separated at reflecting surface from the laser beam 1 of the plane of incidence 43 incidents and do not reflect and the composition (m=0) that passes through and at the composition of reflecting surface reflection, the composition of reflection is separated into only the reflection once composition, the Shu Chengfen of cutting apart that reflects twice (m=2) and reflect three times of (m=1).

Come the bundle of cutting apart of self-waveguide 4 to overlap and project on the shadow surface 90, copy to the y direction replica lens 61 (cylindrical lens) on the shadow surface and constitute by cut apart bundle at the y steering handle at the collector lens 62 (cylindrical lens) of x direction optically focused but overlap irradiation part 6 by overlapping irradiation part 6.

The replica lens 61 of y direction is by x direction collector lens 62, on shadow surface 90, extends the length of regulation in the y direction, and x direction collector lens 62 makes light beam converge in the x direction to be wire, in view of the above, to have obtained the illumination beam 19 of linearity profile on shadow surface.

In the present embodiment, shown in Figure 30 B, as overlapping irradiation part, utilization is configured in the aberration of replica lens 61 in the place ahead of waveguide 4, on shadow surface 90, make and respectively cut apart bundle 16a～16s each other in the irradiation of staggering a little of y direction, in view of the above, as Figure 30 face of land that C illustrates shows, the coincidence at both ends of the y direction of synthetic illumination beam 19 is staggered, and the intensity distributions that makes it is stepped, has alleviated big interference, in uniform range of exposures, can obtain and disturb few uniform illumination beam of intensity.

The example of Figure 31 A and Figure 31 B such as embodiment's 3 is shown in Figure 14, form waveguide 4 by transparent solid, make its axial with it oblique of the plane of incidence 43, make the laser beam refraction of incident, reflect the once light beam of (m=1) from the exit facet ejaculation by reflecting surface, reflect the light beam of twice (m=2), reflect 3 times (m=3) so that the light beam of 6 times (m=6), be radiated on the shadow surface 90 cutting apart bundle by y direction collector lens 61 and x direction collector lens 62, but it is same with Figure 30 A and Figure 30 B, utilize the lens aberration of y direction collector lens 61, make and cut apart on the bundle shadow surface 90 in the drawings, in the irradiation of staggering of y direction, in view of the above, prevented to cut apart bundle interference each other, the homogenising of seeking illumination beam on the shadow surface.

Below variation explanation be in use comprises the optical system of laser beam partition member of cylindrical lens array, by overlapping irradiation part duplicates the laser beam of respectively cutting apart, form with being offset mutually the laser beam irradiation of illumination beam on shadow surface optical system.

Figure 32 A and Figure 32 B comprise extender lens 31, y direction collimation lens 32 and the x direction collimation lens 33 of amplifying laser bundle, parallel beam is incided cut apart in the cylindrical lens array 5 of usefulness.By cylindrical lens array 51, y direction object lens (cylindrical lens) 63 and the x direction collector lens 62 of light beam 15a～15e that cylindrical lens array 5 is cut apart, on shadow surface, obtain the illumination beam 19 of the wire profile that extends in the y direction by duplicating usefulness.And, regulate this object lens 63, the bundle 16a～16e of cutting apart from the laser beam partition member is shone on the shadow surface 90 with staggering each other, obtain illumination beam 19, in view of the above, prevent to cut apart interfering with each other of bundle on the shadow surface, seek the intensity homogenising of illumination beam in the y direction.At this moment, shown in Figure 30 C, the both ends of the y direction of illumination profile show stair-stepping intensity distributions, can obtain showing equally distributed illumination beam scope betwixt.

Shown in Figure 33 A and Figure 33 B, the variation of present embodiment is being cut apart with cylindrical lens array 5 and is being duplicated with configuration retardation plate 7 between the cylindrical lens array 51 and reduce the interference of adjacent divided bundle on shadow surface on the lasing aperture as optical delay components.In this example, what the skew of respectively cutting apart bundle when forming the coincidence that produces because of object lens 63 caused interfering alleviates, work with the effect that multiplies each other that alleviates of the interference of respectively cutting apart interfascicular that produces because of optical delay, have the advantage that can further reduce the change of interfering the intensity distributions that causes.

In the present embodiment, in optical delay components, restraint configuration light transmission retardation plate 7 intrafascicular cutting apart every one in a plurality of the cutting apart of arranging.See through retardation plate 7 by the light beam that makes the adjacent any one party of cutting apart bundle, the optical path difference more than the adjacent interference distance of cutting apart interfascicular formation space.

Below, illustrate in the homogenising parts and to utilize the side that makes the described adjacent divided bundle of cutting apart bundle with respect to the opposing party's the polarization direction example of the polarization member of quadrature in fact.Example shown in Figure 34 make laser beam from the lasing light emitter to the extender lens between 31 in advance by optically-active plate 71, cutting apart among bundle 15a～15e of cutting apart inserting half-wave plate 8 by cutting apart in the y direction as the optically-active parts with cylindrical lens array 5.But half-wave plate 8 is inserted into every one cut apart and restraints among 15a, 15c, the 15d, does not insert in cutting apart among bundle 15b, the 15d of other.In view of the above, adjacent divided interfascicular (for example, is cut apart between bundle 15a and the 15b, cut apart bundle 15b and 15c or other adjacent cut apart interfascicular), polarization angle is quadrature in fact, has suppressed the interference on shadow surface 90, can make the intensity distributions homogenising based on the interference of the illumination beam 19 that overlaps.In the present example, in a light beam, inserted half-wave plate 7 in that the y direction is divided, polarized light by duplicating with lens lighting to shadow surface 90, but, here respectively cut apart the y direction of bundle on shadow surface and stagger overlappingly by regulating object lens 63, making, prevent to cut apart the interference of interfascicular.The stagger intensity distributions of the illumination beam 19 of light beam irradiates on shadow surface 90 time of expression, but at the both ends of the illumination beam 19 of y direction, intensity distributions is reduced to stepped, interferes few even distribution but the major part except both ends has obtained.

Claims (15)

1. the optical system of a laser beam uniform irradiation comprises:

From the laser beam of LASER Light Source in beam cross section, spatially be divided into the laser beam partition member of cutting apart bundle; And

Be radiated at coincidence irradiation part on the shadow surface cutting apart Shu Chonghe;

It is characterized in that:

Described laser beam partition member is waveguide or cylindrical lens array,

Described coincidence irradiation part comprises replica lens, and

Described laser wants partition member to be arranged on the upstream side of described coincidence irradiation part,

Make the described width of cutting apart bundle greater than, equal 1/2 times of space interference distance of the cross-wise direction of lasing aperture.

2. optical system according to claim 1, wherein: described laser beam cut apart width greater than, equal the space interference distance.

3. the optical system of a laser beam uniform irradiation comprises:

From the laser beam of LASER Light Source in beam cross section, spatially be divided into the laser beam partition member of cutting apart bundle;

Be radiated at coincidence irradiation part on the shadow surface cutting apart Shu Chonghe; And

Make the uniform homogenising parts of beam intensity on the shadow surface;

It is characterized in that:

Described laser beam partition member is waveguide or cylindrical lens array,

Described coincidence irradiation part comprises replica lens, and

Described laser wants partition member to be arranged on the upstream side of described coincidence irradiation part,

Described homogenising parts comprise optical delay components, and an adjacent one another are adjacent side of cutting apart bundle who is used to make the described light beam of cutting apart is long with respect to the interference distance of the time of this laser beam of the opposing party's retardation ratio.

4. optical system according to claim 3, wherein: described optical delay components is a retardation plate, it so that separate on this space adjacently cut apart intrafascicular any a branch of mode that sees through and be configured in restrainted spatially in the separate areas a plurality of cutting apart.

5. optical system according to claim 4, wherein: described laser beam partition member is the waveguide with one dimension direction of reflecting surface respect to one another, described coincidence irradiation part comprises the bundle of cutting apart from the laser beam partition member is copied to replica lens on the shadow surface, and each retardation plate is configured near the focal position of the replica lens of cutting apart bundle.

6. optical system according to claim 5, wherein: the optical axis of configuration incident laser is with respect to the central shaft oblique between waveguide and its reflecting surface, make between reflecting surface, do not produce do not reflect and pass through cut apart bundle, any one that makes two groups of illumination beams adjacent one another are is by single retardation plate.

7. optical system according to claim 4, wherein: described laser beam partition member is the cylindrical lens array of cutting apart usefulness that one dimension is cut apart laser beam;

Described retardation plate is configured spatially to have separated in a plurality of zones of cutting apart bundle that formed by the described cylindrical lens array of cutting apart usefulness, and any one that makes adjacent divided bundle sees through.

8. the optical system of a laser beam uniform irradiation comprises:

From the laser beam of LASER Light Source in beam cross section, spatially be divided into the laser beam partition member of cutting apart bundle;

Be radiated at coincidence irradiation part on the shadow surface cutting apart Shu Chonghe; And

Make the uniform homogenising parts of beam intensity on the shadow surface;

It is characterized in that:

Described laser beam partition member is waveguide or cylindrical lens array,

Described coincidence irradiation part comprises replica lens, and

Described laser wants partition member to be arranged on the upstream side of described coincidence irradiation part,

Described homogenising parts comprise the optically-active parts, are used for making a side that adjacent one another are adjacent of the described light beam of having cut apart cut apart bundle with respect to the opposing party's polarization direction quadrature in fact.

9. optical system according to claim 8, wherein: described optically-active parts are the optically-active plates that are configured spatially to have separated in a plurality of zones of cutting apart bundle, are used to make separate on this space adjacent to cut apart any one polarization direction quadrature in fact of bundle.

10. according to Claim 8 or 9 described optical systems, wherein: described laser beam partition member is the waveguide with one dimension direction of reflecting surface respect to one another, described coincidence irradiation part comprises the bundle of cutting apart from the laser beam partition member is copied to replica lens on the shadow surface, and described optically-active component configuration is near the focal position of the replica lens of cutting apart bundle.

11. optical system according to claim 10, wherein: the optical axis of incident laser is with respect to the central shaft oblique between waveguide and its reflecting surface, make between reflecting surface, do not produce do not reflect and pass through cut apart bundle.

12. according to Claim 8 or 9 described optical systems, wherein: described laser beam partition member is the cylindrical lens array of cutting apart usefulness that one dimension is cut apart laser beam, described optically-active parts are configured spatially to have separated in a plurality of zones of cutting apart bundle that formed by the cylindrical lens array of cutting apart usefulness, make the polarization direction quadrature of any one party of adjacent divided bundle with respect to the opposing party.

13. according to Claim 8 or 9 described optical systems, wherein: disposed and be inserted into cutting apart of described the opposing party of intrafascicular optical length compensating plate, be used to make the opposing party's the optical length of cutting apart bundle identical in fact with a described side's the optical length of cutting apart bundle.

14. the optical system of a laser beam uniform irradiation comprises:

From the laser beam of LASER Light Source in beam cross section, spatially be divided into the laser beam partition member of cutting apart bundle; And

Be radiated at coincidence irradiation part on the shadow surface cutting apart Shu Chonghe;

It is characterized in that:

Described laser beam partition member is waveguide or cylindrical lens array,

Described coincidence irradiation part comprises replica lens, and

Described laser wants partition member to be arranged on the upstream side of described coincidence irradiation part,

Described coincidence irradiation part makes respectively to be cut apart bundle displacement each other on shadow surface, duplicates, and forms illumination beam.

15. optical system according to claim 14, wherein: described laser beam partition member comprises the waveguide of the one dimension direction with reflecting surface respect to one another or cuts apart the cylindrical lens array of usefulness, and described coincidence irradiation part is the cylindrical lens with lens aberration.

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