CN103543485A - Manufacturing method of planar double-blazed-grating - Google Patents

Abstract

The invention relates to a method for making a plane double blazed grating, the steps of which are: a. After dust removal and cleaning of the plane glass substrate, chrome film and aluminum film are successively plated on the surface; b. A carving knife is installed on the grating Place the base on the marking machine at the same time; c. Start the motor for pre-scribing, use an electron microscope to observe the pre-scribing groove shape, and adjust the knife angle inclination and back angle height of the carving knife according to the groove shape to obtain ideal Groove type, fix the substrate and drop silicone oil on its surface; d, fix the carving knife and start the formal marking, stop the motor after carving the grating of the first diffraction angle, rotate and select the second carving knife to fix the position and start the second Scribing of gratings with two diffraction angles; e. After finishing the scribing work, remove the residual silicone oil from the grating to make a double blazed grating. The invention is suitable for common grating marking machines, and the grating produced is suitable for portable spectrometers with wide band, small volume and integration.

Description

Fabrication method of planar double blazed grating

technical field

The invention relates to a manufacturing method of a diffractive optical element, in particular to a marking manufacturing method of a plane double blazed grating.

Background technique

Diffraction grating is an extremely widely used and very important high-resolution dispersive optical element, which is widely used in scientific fields such as monochromator, spectral analysis, optical communication technology and optical metrology technology. In spectroscopic instruments, gratings are core components that require high precision in spectroscopic analysis. Since gratings have been successfully developed and widely used, diffraction gratings have almost replaced the previous prisms as the dispersion elements of a new generation of spectroscopic instruments. The accuracy of gratings and Its diffraction wavelength and other factors have a profound impact on astronomy, aerospace, medicine, geology and other scientific and technological fields.

A general diffraction grating has only one diffraction angle. As we all know, most of the light wave energy of the incident light is concentrated in the zero-order direction, but it cannot separate various wavelengths, and the light intensity in the higher-order order with dispersion function is very weak. . In practical applications, it is necessary to concentrate as much incident light energy as possible on a specific diffraction order according to different applications. Therefore, it is necessary to calculate the diffraction angle of the grating according to the different application conditions of the grating, and determine its groove shape, so that the main maximum direction of the grating diffraction is consistent with the diffraction order direction calculated by the entire grating theory, and the diffracted light energy from the zero-order direction Transfer to the specific level designed. The spectral intensity detected from this particular order is the largest, and this phenomenon is blazed, and this kind of grating is called blazed grating. On the other hand, with the development of science and technology, in order to adapt to the miniaturization and integration of spectroscopic instruments, there are more and more studies on double blazed gratings, because double blazed gratings can be used in a wide band (such as From the ultraviolet to the visible bands) obtain higher diffraction efficiency, reduce the number of gratings used in the same spectroscopic instrument, simplify the structure of the spectrometer, and have a relatively broad market prospect.

At present, the main method of making double blazed gratings is to grind two blades with different angles on a knife, which has great difficulties in sharpening technology; the other method is to replace the knife halfway, but this replacement The engraving knife will cause the connection error of the engraving line due to the vibration and improper connection of the engraving knife position, which cannot guarantee the diffraction wavefront of the grating and reduce the diffraction efficiency of the grating; there is another method to make a double blazed grating by using the holographic method , Chinese invention patent "a method for manufacturing holographic double blazed grating", patent number: 201110318711, this method is easy to realize, but the shape of the groove etched by this holographic manufacturing method is difficult to control, the groove surface is relatively rough, and the diffraction efficiency is relatively low. Sometimes it is difficult to meet the application requirements of the spectrometer.

Contents of the invention

In order to overcome the defects of the prior art described above, the present invention provides a method for manufacturing a planar double blazed grating, which improves the method of replacing the engraving knife during the precise transition from the A blazed area to the B blazed area, and designs a The high-precision disc rotating structure can carve a double blazed grating at one time, precisely realize the control of the double blazed angle, and improve the diffraction efficiency of the grating.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for mechanically marking and manufacturing a planar double blazed grating, comprising marking the gratings in the A blazed area and the B blazed area, and the specific steps are:

(1) Grating of the grating in the A blaze area

a. A layer of chromium film and a layer of aluminum film are successively coated on the flat glass substrate after cleaning and dust removal;

b. Two carving knives are installed on the vertical knife bridge of the rotating disk of the marking mechanism, and the angle of the blade ground by each carving knife is consistent with the blade angle required by the design;

c. Place the flat glass substrate on the horizontal indexing work platform with the lead screw as the traction mechanism, start the motor for pre-scribing, observe the pre-scribing groove shape with an electron microscope, and adjust the knife angle of the carving knife according to the groove shape Obtain the desired groove shape according to the degree and back angle height, then fix the base, and drop silicone oil on its surface;

d. The working platform drives the grating base to make a transverse indexing movement with a feed rate of a grating constant d, and the knife bridge drives the first engraving knife 1 to reciprocate to make a vertical marking movement. In this way, the grating of the shining area A is completed. engraved;

(2) Scoring of the grating in the B blaze area

a. After the scribing of the grating in the blazing area of A is completed, stop the motor, rotate the rotating disc equipped with two carving knives, rotate the second carving knife 2 to the position of the second carving knife 1, and fix it;

b. Start the motor, the working platform continues to drive the grating base to perform a transverse indexing movement with a feed rate of a grating constant d, and the knife bridge drives the second engraving knife 2 to reciprocate to perform a vertical marking movement until the B flashing area is completed grating marking;

(3) After the scribing of the gratings in the A blazed area and the B blazed area is completed, remove the residual silicone oil from grating cleaning to obtain a double blazed grating.

In step a of scribing the blaze region grating, the size of the flat glass substrate is 100mm×50mm, the thickness of the chromium film is 100nm, and the thickness of the aluminum film is 1um.

In the above steps, two knife holders on the same straight line are made on the rotating disc used, and a bayonet for precisely fixing the position of the engraving knife during rotation is made on the edge of the rotating disc along the vertical direction of the tool holder. .

In the above steps, the scribing action from the blazing area A to the blazing area B of the flat glass substrate is continuous scribing.

The horizontal indexing movement of the working platform is realized by the precise subdivision of the screw rod by the grating ruler, and the vertical movement of the marking mechanism is driven by the servo motor to drive the transmission belt connected to the knife bridge to guide the carving knife to realize the marking action.

The vertical distance of the carving knife installed on the rotating disc of the scoring mechanism is greater than 50mm.

Compared with the prior art, the beneficial effect of the present invention is that: in the conversion process of the knives from the A blazing area to the B blazing area, the working platform is kept fixed, and the rotation of the disc is designed by calculating the distribution angles of the two carving knives. The position and accuracy of the bayonet can achieve the precise transition of the engraved line from the A blaze area to the B blaze area, which improves the diffraction efficiency of the grating; through the pre-designed A blaze angle and B blaze angle, sharpen the corresponding cutting edge, which greatly reduces the The difficulty of grinding double blades on the same scribing knife also greatly improves the scribing quality and scribing accuracy during the scribing process; the present invention continues to use the general structure of the ordinary scribing machine, only redesigning the scribing mechanism And it can be directly installed on the original marking machine, which reduces the cost.

Description of drawings

Fig. 1 is the schematic diagram of making the planar double blazed grating of the present invention;

Fig. 2 is a schematic top view of the double blazed grating of the present invention;

Fig. 3 is a schematic side view of the ruled double blazed grating of the present invention.

Detailed ways

The method for making a planar double blazed grating according to the present invention will be described in detail below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only illustrative illustrations of the present invention, and are not intended to limit it in any way.

As shown in Figures 1 to 3, the manufacturing method of the planar double blazed grating, the specific steps are:

The ordinary grating marking machine is used as the production machine. The main components of the grating marking machine include a working platform for transverse indexing movement, a marking mechanism for reciprocating motion guided by the knife bridge 8, and the marking mechanism is designed and installed with the same The rotating disk 6 structure with two carving knives fixed on the straight line can be replaced and selected with different knife edge angles according to different grating conditions. The design requirement for the rotating disk 6 is to calculate and determine the positions of the bayonets on the edge of the disk corresponding to the vertical direction in the knife holder 7 of the two carving knives, so as to ensure that the blades of the carving knives are absolutely on the same straight line after rotating the disk 6 , so as to ensure the precise transition from the last scribe line in A blaze area 4 to the first scribe line in B blaze area 5 during scribing. Fix the flat glass substrate 3 of the grating to be scored on the working platform. The flat glass substrate 3 is a flat glass substrate with a specification of 100mm×50mm. After cleaning and dust removal, use a vacuum coating machine to coat the flat glass substrate 3 respectively. A layer of chromium film and aluminum film, the thickness of the chromium film is 100nm, and the thickness of the aluminum film is 1um. When placed, the aluminum film layer of the flat glass substrate 3 faces upward. Before formal scribing, the first scribing knife 1 and the second scribing knife 2 must be used to pre-scribe the flat glass substrate 3, and observe the shape and uniform distribution of the scribing lines on the substrate after the pre-scribing under an electron microscope. Adjust the position of the carving knife for the pre-marked groove and fix it, and then adjust the marking machine to record the ideal marking state. Pre-scribing After adjusting the carving knife, the formal scoring can begin.

After the adjustment is completed, the cutting knife is used to perform a preset scoring action on the flat glass substrate 3 . The preset marking action means that when marking each marking line, the horizontal indexing motion of the working platform and the vertical reciprocating motion of the carving knife have been pre-calculated and written into a corresponding specific computer software control program, and the motor is controlled by the program. Automatically execute the marking action of each marking line. The working platform connected to the screw rod drives the grating base to perform a transverse indexing motion with a feed rate of a grating constant d, and the knife bridge 8 drives the first engraving knife 1 to reciprocate to perform vertical marking motion. Going round and round like this, after finishing the scoring of the 4 gratings in the A blaze area, stop the motor, suspend the marking work, rotate the rotary disc 6 equipped with two carving knives, and rotate the second carving knife 2 to the position of the first carving knife 1. Position, fix the position of the carving knife. Start the motor, the working platform continues to drive the grating base to perform a horizontal indexing movement with a feed rate of a grating constant d, and the knife bridge 8 drives the second engraving knife 2 to reciprocate for vertical marking movement until the B blazing area 5 is completed. Raster scoring.

As shown in Figure 1, according to the design parameters of the planar double blazed grating, there are two different blazed angles θ ₁ and θ ₂ on the same substrate, and the corresponding A blazed area 4 and B blazed area 5 are in the marking process There is no difference between the marking of neutral and ordinary gratings. When the flashing area 4 of A is scored to the last engraved line set, it is necessary to replace the engraving knife with different blades at this time, keep the working platform fixed, and gently rotate the rotating disc 6 of the marking mechanism, and the rotating disc 6 The internal design of the steel ball rolling structure is to reduce the impact of the vibration generated during the rotation on the marking machine, and use the bayonet of the edge of the disc corresponding to the vertical direction in the knife holder 7 of the carving knife to fix the rotating disc 6, To ensure that the position of the carving knife remains unchanged during the marking process. After choosing to replace the second engraving knife 2, the motor continues to start the scoring action of the first engraving line in B shining area 5 from the last engraving line in A shining area 4. Keeping the working platform fixed and ensuring that the bayonet of the rotating disk 6 reaches the corresponding accuracy can ensure the precise transition from the A blazing area 4 to the B blazing area 5 and ensure the diffraction efficiency of the grating. During the marking process, the horizontal indexing movement of the working platform is realized by the precision indexing of the screw rod, and the vertical movement of the marking mechanism is driven by the motor to drive the transmission gear to connect the knife bridge 8 to guide the carving knife to realize the marking action.

After the entire grating is made, a planar double blazed grating with different grating diffraction angles θ ₁ and θ ₂ is formed, and blades with different angles can be ground according to different grating conditions to scribe different diffraction angles. This kind of planar double blazed grating can provide a wider band (such as the ultraviolet-visible band), corresponding to two different diffraction peaks, and is especially suitable for spectroscopic instruments that have certain requirements for instrument volume and working environment.

Wherein, the grating diffraction angle corresponding to the A blaze area 4 is θ ₁ , and the grating diffraction angle corresponding to the B blaze area 5 is θ ₂ . The initial scoring position of the substrate and the feed rate of each groove, as well as the initial position of the carving knife and the movement amount of each scoring have been calculated in advance and input into the computer control software, which is controlled by the computer control software program The motor determines the horizontal and vertical feed of each engraved line, and realizes the engraved action of each engraved groove.

Claims (6)

1. A method for making a planar double blazed grating, comprising marking the A blazed area (4) and the B blazed area (5) grating, characterized in that the specific steps are: 1) A blazing area (4) Scribing of the grating a. A layer of chromium film and a layer of aluminum film are successively coated on the flat glass substrate (3) after cleaning and dust removal; b. Two carving knives are installed on the vertical knife bridge (8) of the rotating disk (6) of the marking mechanism, and the angle of the blade ground by each carving knife is consistent with the blade angle required by the design; c. Place the flat glass substrate (3) on the horizontal indexing work platform with the lead screw as the traction mechanism, start the motor for pre-scribing, observe the pre-scribing groove shape with an electron microscope, and adjust the cutting knife according to the groove shape The inclination of the knife angle and the height of the relief angle are used to obtain the desired groove shape, and then the base is fixed, and silicone oil is dripped on the surface; d. The working platform drives the grating base to make a transverse indexing movement with a feed rate of a grating constant d, and the knife bridge drives the first engraving knife (1) to reciprocate to make a vertical marking movement, and so on and on again to complete the A flashing area (4) Grating of the grating; 2) Scoring of B blazing area (5) grating a. After the scribing of the grating in the blazing area (4) of A is completed, stop the motor, rotate the rotating disk (6) equipped with two carving knives, and rotate the second carving knife (2) to the second carving knife (1) position and fix it; b. Start the motor, and the working platform continues to drive the grating base to make a horizontal indexing motion with a feed rate of a grating constant d, and the knife bridge (8) drives the second carving knife (2) to reciprocate to make a vertical marking motion. Until the scoring of the grating in the B blaze area (5) is completed; 3) After the scribing of the gratings in the A blazed area (4) and the B blazed area (5) is completed, remove the residual silicone oil from the grating cleaning to produce a double blazed grating. 2. The method for making a planar double blazed grating according to claim 1, characterized in that, in the step a of marking the grating in the A blaze area (4), the size of the planar glass substrate (3) is 100mm×50mm , the thickness of the chromium film is 100nm, and the thickness of the aluminum film is 1um. 3. The method for making a planar double blazed grating according to claim 1, characterized in that: in the above steps, two tool holders (7) on the same straight line are made on the rotating disk (6), and Each edge of the rotating disk (6) along the vertical line direction in the knife rest (7) makes a bayonet socket for precisely fixing the position of the carving knife when rotating. 4. The manufacturing method of planar double blazed grating according to claim 1, characterized in that: in the above steps, the marking action from the A blazed area (4) to the B blazed area (5) of the planar glass substrate (3) is continuously drawn. 5. The manufacturing method of planar double blazed grating according to claim 1, characterized in that: the horizontal indexing movement of the working platform is realized by the precise subdivision of the screw rod by the grating ruler, and the vertical movement of the marking mechanism is realized by the servo motor Drive the transmission belt connected to the knife bridge to guide the carving knife to realize the scoring action. 6. The manufacturing method of planar double blazed grating according to claim 1, characterized in that: the vertical distance of the carving knife installed on the rotating disc (6) of the marking mechanism is greater than 50mm.

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