The equal bundle device of excimer laser shapingTechnical field
The utility model is the equal bundle device of a kind of shaping of excimer laser, belongs to Laser Processing and applied technical field thereof.
Background technology
Excimer laser is to use laser instrument the most widely in the lasing source of ultraviolet band.Because excimer laser itself belongs to cold laser, no thermal effect, and be simultaneously good directionality, wavelength purity height, output power greatly, the pulse laser that easily absorbed by material, also be applied to many fields of Laser Processing, medical science, scientific research in recent years more and more widely.At present, use excimer laser more widely, its wave band mainly is 193nm argon fluoride (ArF), 248nm KrF (KeF), 308nm chlorination xenon (XeCl) and 351nm xenon fluoride (XeF).But because the principle of work of excimer laser is limit, the laser of output is high-order multi-mode light beam, generally the xsect energy distribution directions X of output beam is Gaussian Energy Distribution, Y-direction is the rectangular light spots of nearly Gaussian Energy Distribution, energy distribution is very inhomogeneous, and this has brought difficulty for the application of excimer laser.
In order to address this problem, just need carry out shaping and homogenising is handled to the light distribution of the excimer laser beam of original output.If can be good at addressing the above problem, can expand excimer laser greatly in the scope of application of each application.
Summary of the invention
The purpose of this utility model is that shaping and homogenising are carried out in the light distribution of the excimer laser beam of original output to be handled and finally obtain an equal Shu Xiaoguo of desirable integer.
The utility model adopts following technical scheme:
The equal bundle device of a kind of excimer laser shaping, it is characterized in that: comprise first microlens array of arranging successively 1, the second saturatingmicro mirror array 2, sphere fourier transform lens 3, focus on target surface 4, described first microlens array 1, the second saturatingmicro mirror array 2, sphere fourier transform lens 3, focusing target surface 4 are fixed in slidingmechanical groove 5.
This integrative-structure as plan-convex shape of lenticule in described first microlens array 1 andsecond microlens array 2, the lenticule progression of forming array is 12 * 12 grades.
The focal length ofsecond microlens array 2 is greater than the focal length of first microlens array 1, and the position ofsecond microlens array 2 is away from the focal plane of first microlens array 1.
Amount to 144 lenticules in described first microlens array 1 andsecond microlens array 2 separately and be fixed by steel metal outer frame and two steel metal platen, the side of two metal platen all has two screws to adjust pressure.
For the material of optical element in the whole optical system, adopted the dissolved hydrogenmolecular conecentration 5 * 1018Molecule/cm3Below through the special quartz of special processing, suppress optical element itself for photonic absorption and the secondary photonic absorption of excimer laser, light transmission rate is high and tolerate excimer laser.
After excimer laser is all restrainted through shaping of the present invention, can obtain the uniform square hot spot of energy height of about a 2 * 2cm in the focal plane of sphere fourier transform lens.Of poor quality and the hot spot internal energy skewness of original excimer laser rectangular light spots shape through behind the equal Shu Zuoyong of this device, can well address the above problem.The realization of this device design can greatly be expanded excimer laser in the scope of application of many applications.
Description of drawings
Fig. 1 is microlens array shaping beam-averaging device device synoptic diagram;
Fig. 2 is the lenticule front view;
Fig. 3 is the lenticule left view;
Fig. 4 is the front view of the special mechanical clamp of microlens array:
Fig. 5 is the left view of the special mechanical clamp of microlens array.
Among the figure: 1, first microlens array, 2, second microlens array, 3, the Fourier spherical mirror, 4, focus on target surface, 5, the sliding mechanical stationary platform, 6, pressure adjustment screw, 7 steel metal platen, 8, the steel metal outer frame, 9, microlens array.
Embodiment
For the equal bundle device of this laser shaping, following embodiment is arranged:
The utility model is at excimer laser, the structure of whole optical system is seen Fig. 1, after the laser incident successively through first microlens array, 1second microlens array 2, focusing target surface 4 at sphere fourier transform lens 3 obtains the uniform square hot spot of light energy distribution at last, and whole optical system is fixed in slidingmechanical groove 5.
When laser incided first microlens array 1, microlens array can split into incident light the light pencil of many propagation independent of one another, served as the role of multiple light source.The adding ofsecond lens arra 2 makes two lenticule battle arrays and fourier transform lens row form a lot of kohler's illumination systems parallel to each other.Second lens arra 2 is in conjunction with sphere fourier lense 3, served as an objective lens array, picture with each the bar light pencil generation on first microlens array 1, be superimposed upon all on the bundle face, cut the light uniformity coefficient and will be higher than initial incident beam far away because beamlet is square, what therefore last stack obtained is a square and the uniform hot spot of energy distribution.This device has shaping simultaneously and all restraints two kinds of abilities.
Consider that the excimer laser energy is very big, if allow the position of second microlens array that the ruined danger of material is arranged in the focal plane of first microlens array.Therefore, the structure and parameter of optical system is realized in the following way: at first first microlens array 1 is on the focal plane ofsecond microlens array 2, make the focal length ofsecond microlens array 2 greater than first microlens array 1 then, the position of suchsecond microlens array 2 will be away from the focal plane of first microlens array 1, so just can when avoiding material damage, satisfy the kohler's illumination principle, realize the shaping of excimer laser and all restraint.
The lenticule that constitutes microlens array is seen Fig. 2, Fig. 3, and lens are the integrative-structure of plan-convex shape, fixes by mechanical clamp behind the abrasive forming, and the microlens array optical reflection face that constitutes than traditional cylindrical mirror stack lacks, and light transmission rate improves.
The front view of the special mechanical clamp of microlens array is seen Fig. 4, and left view is seen Fig. 5.Whole microlens array is 12 * 12 grades and amounts to 144 lenticules and be fixed by steel metal outer frame and two steel metal platen that the side of two metal platen all has two screws to adjust pressure.
For the material of optical element in the whole optical system, adopted the dissolved hydrogenmolecular conecentration 5 * 1018(molecule/cm3) following special quartz through special processing, suppressing optical element itself for photonic absorption and the secondary photonic absorption of excimer laser, light transmission rate is high and tolerate excimer laser.
Concrete parameter designing is as described below in the present embodiment:
1) first microlens array 1:
The focal length of lenticule unit is 60mm, and thickness is 4mm, and iris shape is square, and the convex curvature radius is 30.5132mm, and period pitch is 3.4mm.
2) second microlens array 2:
The focal length of lenticule unit is 70mm, and thickness is 4mm, and iris shape is square, and the face type is the plan-convex type, and the convex curvature radius is 35.5985mm, and period pitch is 3.4mm.
3) the Fourier spherical mirror 3:
The focal length of lens is 500mm, and lens thickness is 4mm, and the dual edge height is and is that 60mm, face type are the biconvex type, and the radius-of-curvature of front surface is 507.876mm, and the radius-of-curvature of rear surface is-507.876.
4) structural parameters of the equal bundle device optical system of whole compound eye type excimer laser are as follows:
The central axis of first microlens array 1,second microlens array 2, Fourier spherical mirror 3 should be on same straight line, and the edge of first lens arra and second lens arra is parallel to each other, and three optical elements are fixed on the sliding mechanicalstationary platform 5 successively.Spacing in the space between first microlens array and second microlens array is 70mm, and the spacing between Fourier spherical mirror and second microlens array is 30mm, and the focusing target surface 4 that shaping is all restrainted is positioned at the Fourier spherical mirror place, focal plane of 500mm afterwards.
After the whole optical system encapsulation is fixing, use the excimer laser of Lamb-da-Physik LPX305iF type excimer laser 248nm from the port incident of first microlens array, all restrainting the square hot spot that the plane obtains being about 2 * 2cm and energy even through the equal Shu Houhui of shaping.The energy distribution image of hot spot is taken by SPIRICON LBA-USB-L230 laser beam quality analyser and is obtained, and sees Fig. 7, Fig. 8.