CN101750649A - Groove spacing accurately adjusting device in holographic grating manufacturing light path - Google Patents

Abstract

The invention relates to a device for accurately adjusting the density of reticle lines in the optical path for making holographic gratings, which belongs to a device related to the field of spectrum technology. The technical problem to be solved is to provide a device for accurately adjusting the density of reticle lines in the light path for making holographic gratings. The technical solution includes laser light source, first plane reflector and second plane reflector, spatial filter, collimating reflector, adjusting reflector, interference field, reference grating, receiving screen, supporting rotary table and other components. By adjusting the upper turntable and the adjusting screw group on the supporting rotary table to change the pitch and rotation of the adjustment reflector and the reference grating, the two beams of recording light are diffracted by the reference grating and superimposed to produce Moiré fringes. Through the inspection of Moiré fringes, The precise adjustment of the period of the interference field fringes is realized, and the density of the interference fringes is the line density of the holographic grating to be fabricated. The device simplifies the adjustment steps, shortens the adjustment time, and improves the adjustment accuracy of the holographic grating line density.

Description

The device of accurately adjusting groove density in a kind of holographic grating making optical path

Technical field

The invention belongs to the device of accurately adjusting groove density in a kind of holographic grating making optical path that relates in the spectral technique field.

Background technology

When making holographic grating, the grating substrate that scribbles photoresist is placed in the interference field exposes, by the interference fringe in the photoresist record interference field, the density of this interference fringe is promptly made the incisure density of grating.The dispersive power and the resolution of the incisure density decision grating of grating, the accuracy of grating constant directly influences the wavelength accuracy of spectral instrument.Therefore, in holographic grating making, accurately adjusting groove density becomes vital work.

The prior art the most approaching with the present invention is that China Patent No. is CN1544994A, denomination of invention is " method of accurately adjusting groove density in a kind of manufacturing of plane holographic grating ", the holographic grating exposure device that provides in the method comprises LASER Light Source 1, first catoptron 2 and second catoptron 3, expands and restraint wave filter 4, collimating mirror 5, the first adjustment catoptron 6, second adjustment catoptron 7 and the interference field 8 as shown in Figure 1; As the benchmark grating, the interference fringe density of adjusting interference field 8 is consistent with benchmark grating incisure density, makes the nominal value of holographic grating incisure density to be made consistent with the incisure density of machine engraving grating with the machine engraving grating of standard.This method is simple and feasible, easy operating, accurately control plane holographic grating incisure density.But this device is the device at the double mirror exposure with two adjustment catoptrons, is not suitable for Lip river Chinese mugwort mirror exposure optical system.When the Chinese mugwort mirror exposure of accurate adjustment Lip river, need provide a kind of adjusting gear of practicality.

Summary of the invention

In order to overcome the defective that above-mentioned prior art exists, the objective of the invention is to set up the device of the accurate adjustment grating line density of the Lip river Chinese mugwort mirror exposure optical system that a kind of simple and feasible being applicable to have only an adjustment catoptron.

The technical problem to be solved in the present invention is: the device that accurately adjusting groove density in a kind of holographic grating making optical path is provided.The technical scheme of technical solution problem is: as shown in Figure 2, comprise LASER Light Source 11, first plane mirror 12 and second plane mirror 13, spatial filter 14, collimating mirror 15, adjust catoptron 16, come from the second bundle incident light 18, interference field 19, benchmark grating 20, receiving screen 21, support universal stage 22 that first of collimating mirror 15 is restrainted incident light 17, come from adjustment catoptron 16; Wherein support universal stage 22 as shown in Figure 3, comprise lower floor's platform 23, upper strata turntable 24, rotation draw-in groove 25, holding screw 26, rotary middle spindle 27, adjust Reflector base 28, the first adjusting screw group 29, Optical grating base 30, the second adjusting screw group 31 and the 3rd adjusting screw group 32; On the optical axis of the laser beam direction of propagation of LASER Light Source 11, be equipped with first plane mirror 12, first plane mirror 12 is installed with optical axis angle at 45, on the catoptrical light path of first plane mirror 12, be equipped with second plane mirror 13, second plane mirror 13 is installed with optical axis angle at 45, on the catoptrical light path of second plane mirror 13, be equipped with spatial filter 14, form spherical wave through spatial filter 14 backs, place collimating mirror 15 in the spherical wave direction of propagation, and the focal position of collimating mirror 15 is positioned at spherical wave wave source point, the position of spherical wave wave source point is in the exit of spatial filter 14, laser beam becomes collimated light beam behind collimating mirror 15 like this, supports the light path that universal stage 22 places this collimated light beam; Support universal stage 22 at the middle and upper levels turntable 24 is connected by rotary middle spindle 27 with lower floor platform 23, upper strata turntable 24 can center on rotary middle spindle 27 and rotate, and can use holding screw 26 by rotating draw-in groove 25 upper strata turntable 24 to be fixed on lower floor's platform 23; Lay on the upper strata turntable 24 and adjust Reflector base 28 and Optical grating base 30, and these two pedestals become 90 ° of angles to install, the first adjusting screw group 29 is positioned at the both sides of adjusting Reflector base 28, be used to regulate the pitching of adjusting Reflector base 28, the second adjusting screw group 31 is positioned at the both sides of Optical grating base 30, be used to adjust the pitching of Optical grating base 30, the 3rd adjusting screw group 32 is positioned at the both sides of Optical grating base 30 left ends, is used to adjust the rotation of Optical grating base 30; Adjusting catoptron 16 is placed on the adjustment Reflector base 28, benchmark grating 20 is placed on the Optical grating base 30, and adjust catoptron 16 and become 90 ° of angles with the surface of benchmark grating 20, the collimated light beam that collimating mirror 15 is sent shines the surface of adjusting catoptron 16 and benchmark grating 20; The first bundle incident light 17 that comes from collimating mirror 15 intersects with the second bundle incident light 18 that reflects through adjustment catoptron 16, form interference field 19 at intersectional region, and benchmark grating 20 is positioned at interference field 19, the grating line direction of benchmark grating 20 is restrainted the plane that incident light 18 is formed perpendicular to the first bundle incident light 17 and second, and the surface of benchmark grating 20 is towards collimating mirror 15.

Principle of work explanation of the present invention: in holographic grating exposure interference field, place the support universal stage that catoptron and benchmark grating are adjusted in a carrying, change pitching and the rotation of adjusting catoptron and benchmark grating by adjusting the upper strata turntable and the adjusting screw group that support on the universal stage, superimposed generation Moire fringe after making two beam recording light through the benchmark optical grating diffraction, by check, realize accurate adjustment to the interference field fringe period to Moire fringe.In interference field 19, insert one and overlap the device that is used to adjust Lip river Chinese mugwort mirror exposure optical system incisure density, Optical grating base 30 is arranged on the device and adjust Reflector base 28, and can adjust the pitching and the orientation of Optical grating base 30 and adjustment Reflector base 28; To adjust catoptron 16 is placed on the adjustment Reflector base 28, benchmark grating 20 is placed on the Optical grating base 30, adjust the 3rd adjusting screw group 32, angle is 90 ° between change benchmark grating 20 and the adjustment catoptron 16, at this moment, the first bundle incident light 17 and the second bundle incident light 18 shine on the surface of benchmark grating 20; Adjust the first adjusting screw group 29 and the second adjusting screw group 31, the plane that benchmark grating 20 and adjustment catoptron 16 surfaces and the first bundle incident light 17 and the second bundle incident light 18 are formed is vertical; Unclamp holding screw 26, is that the center is along 25 rotations of rotation draw-in groove with upper strata turntable 24 with rotary middle spindle 27,-2 order diffraction light and second that make the first bundle incident light 17 pass through benchmark gratings 20 are restrainted incident light 18 process benchmark gratings 20+1 order diffraction light and are shone on the receiving screen 21 along equidirectional, on receiving screen 21, can form Moire fringe, the careful adjusting adjusted the first adjusting screw group 29 and the second adjusting screw group 31, change the angle of pitch and the position angle of adjusting catoptron 16 and benchmark grating 20, restraint the plane that incident light 18 is formed to guarantee the Moire fringe on receiving screen 21 perpendicular to the first bundle incident light 17 and second, and the width of fringe maximum, locking holding screw 26; At this moment, the interference fringe density in the interference field 19 is identical with the incisure density of benchmark grating 20; As shown in Figure 4, take off benchmark grating 20 shown in Figure 2 and receiving screen 21, the grating substrate 33 that scribbles photoresist is placed on the position at benchmark grating 20 places original shown in Figure 2, photoresist in the grating substrate 33 record by the first bundle incident light 17 and the second bundle incident light 18 forms interference fringe, the density of this interference fringe is by the incisure density of making holographic grating.

Good effect of the present invention: by the simple and feasible device that can accurately adjust grating line density of a cover, adopt Moire fringe technique accurately to adjust incisure density in the holographic grating making optical path, will be converted to measurement the period measurement of micron-sized interference field interference fringe to millimetre-sized Moire fringe; Use this device to simplify set-up procedure, shortened the adjustment time, improved the adjustment precision of holographic grating incisure density.

Description of drawings

Fig. 1 is that the prior art patent No. is the holographic grating exposure device structural representation of CN 1544994A;

Fig. 2 is an apparatus structure synoptic diagram of accurately adjusting grating line density in the holographic grating making optical path of the present invention;

Fig. 3 is the structural representation that supports universal stage 22 among Fig. 2;

Fig. 4 is the light path synoptic diagram that adds the grating substrate 33 that scribbles photoresist in the holographic grating exposure device light path shown in Figure 2.

Embodiment

The present invention presses Fig. 2,3, structure shown in 4 is implemented, wherein, LASER Light Source 11 adopts krypton ion laser, wavelength is 413.1nm, first plane mirror 12 and second plane mirror 13 are the substrate of glass aluminum reflector, spatial filter 14 is made up of microcobjective and pin hole, the bore of collimating mirror 15 is φ 320mm, focal distance f=1.2m, adjusting catoptron 16 is the substrate of glass aluminum reflector, benchmark grating 20 need be according to the actual reflection grating that requires the choice criteria incisure density, receiving screen 21 adopts ordinary white frosted glass, K9 optical glass is adopted in grating substrate 33, the photoresist that applies on the K9 optical glass is the Shipley1805 type photoresist that Japan produces, and adjusts accurately that each mechanical structured member all adopts steel to complete through machining in the device of holographic grating incisure density.

Claims (1)

1. A device for accurately adjusting the line density in the optical path of holographic grating production, comprising a laser light source (11), a first plane reflector (12) and a second plane reflector (13), a spatial filter (14), a quasi- Straight reflector (15), interference field (19); It is characterized in that also comprising adjusting reflector (16), the first bundle of incident light (17) from collimating reflector (15), from adjusting reflector ( 16) the second bundle of incident light (18), reference grating (20), receiving screen (21), support rotary table (22); wherein support rotary table (22) comprises lower floor platform (23), upper floor turntable (24) , rotation card slot (25), fastening screw (26), rotation center shaft (27), adjustment mirror base (28), first adjustment screw group (29), grating base (30), second adjustment Screw group (31) and the 3rd adjusting screw group (32); On the optical axis of the laser beam propagating direction of laser light source (11), be provided with the first plane reflector (12), the first plane reflector (12) and The optical axis is installed at an included angle of 45°, and a second flat reflector (13) is placed on the optical path of the reflected light of the first flat reflector (12), and the second flat reflector (13) forms a 45° clip with the optical axis. Angle installation, a spatial filter (14) is placed on the optical path of the reflected light of the second plane reflector (13), a spherical wave is formed after passing through the spatial filter (14), and a collimating reflector ( 15), and the focus position of the collimating reflector (15) is positioned at the source point of the spherical wave, and the position of the source point of the spherical wave is at the exit of the spatial filter (14), and the laser beam becomes Collimated light beams, the supporting rotary table (22) is placed in the optical path of the collimated beams; the upper turntable (24) in the supporting rotary table (22) is connected with the lower floor platform (23) through the central axis of rotation (27), and the upper floor turntable ( 24) It can rotate around the central axis of rotation (27), and the upper turntable (24) can be fixed on the lower stage (23) by using the fastening screw (26) through the rotation card slot (25); There are adjustment reflector base (28) and grating base (30), and these two bases are installed at an angle of 90°, and the first adjustment screw group (29) is located on both sides of the adjustment reflector base (28) , the second adjusting screw group (31) is located on both sides of the grating base (30), the third adjusting screw group (32) is located on both sides of the left end of the grating base (30); the adjusting reflector (16) is placed on the adjusting reflector On the mirror base (28), the reference grating (20) is placed on the grating base (30), and the surface of the adjusting reflector (16) and the reference grating (20) forms an angle of 90°, so that the collimating reflector ( 15) The collimated light beam sent irradiates the surface of the adjusting reflector (16) and the reference grating (20); the first beam of incident light (17) from the collimating reflector (15) and the adjusted reflector (16) The reflected second beam of incident light (18) intersects to form an interference field (19) in the intersection area, and the reference light The grating (20) is located in the interference field (19), the direction of the grating lines of the reference grating (20) is perpendicular to the plane formed by the first beam of incident light (17) and the second beam of incident light (18), and the reference grating (20 ) faces the collimating mirror (15).

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