Electrum diffraction grating for pulse compression and its manufacturing method

Abstract

An electrum diffraction grating for pulse compression and a method for manufacturing the same, in which the metal layer of the electrum diffraction grating is a binary or multi-component mixture of gold with silver or a platinum-based element in an appropriate blend ratio, or a thin film with gold on top and silver on the bottom, is used. The manufacturing process includes screening the characteristic profile parameters of the electrum diffraction grating and the material blend ratio of the electrum film. The electrum diffraction grating of the present invention expands the frequency range of high diffraction efficiency of the diffraction grating without degrading the optical properties of conventional gold diffraction gratings, improves or resolves the problem of susceptibility to oxidation of pure silver diffraction gratings, and further improves the laser-induced damage threshold of gold diffraction gratings. The process parameters are also applicable to the manufacture of diffraction gratings with meter-level apertures. The diffraction grating and related process parameters of the present invention can be used in the construction of spectrometers, commercial ultrafast laser systems, and large-scale high-peak-power laser systems, and are of great significance for the development of pulse compression diffraction gratings.

Description

[Technical Field]

[0001] The present invention relates to a reflection type diffraction grating, and more particularly to an electrum diffraction grating for pulse compression and a method for manufacturing the same. [Background technology]

[0002] The field of ultra-high-intensity ultra-short pulse lasers is currently at a critical stage, achieving major breakthroughs and expanding applications. Countries are devoting their efforts to developing ultra-high-intensity ultra-short pulse laser sources and cutting-edge scientific and technological innovation platforms based on them. Research institutes around the world are effectively utilizing chirped pulse amplification (CPA) and optical parametric chirped pulse amplification (OPCPA) technologies to increase the peak power of laser devices to tens of petawatts (PW). Over the next decade, 100-PW ultra-high-intensity ultra-short pulse laser devices are expected to be delivered and put into practical use around the world. Major countries are competing to achieve even higher peak powers.

[0003] In the two laser amplification technologies of CPA and OPCPA, the grating compressor is the core module, and the key component in the grating compressor is the grating. Metal gratings have the advantages of wide bandwidth, high efficiency, good surface shape, and wide angular spectrum, so they are widely used in small and large laser devices.

[0004] Currently, to ensure long-term use and stability of characteristics in metal diffraction gratings used for pulse compression, pure gold is used for almost all metal layers. For high-energy laser devices, the purity of gold must reach 99.99% to 99.999%. In response to the requirements for the construction of current and future high-peak-power laser devices, gold diffraction gratings have stable average diffraction efficiencies of 90% to 94% across different bandwidths in the 700-1200 nanometer (nm) range, and their laser-induced damage thresholds are approaching their limits. Therefore, there is an urgent need to develop metal diffraction gratings for pulse compression that retain the advantages of conventional gold diffraction gratings while offering higher laser-induced damage thresholds and better optical and thermodynamic properties.

[0005] No one at home or abroad has yet proposed the design, manufacture, testing, and use of pulse compression electrum gratings. Pulse compression electrum gratings are either binary mixtures of gold and silver, or pulse compression gratings with gold on top and silver on the bottom. The high-conductivity metal film layer improves the diffraction efficiency and laser-induced damage threshold of metal gratings, helping to expand the high-efficiency bandwidth or frequency range. The multi-component mixture structure improves the oxidation resistance of silver and the deformation resistance of pure gold or silver. Research into pulse compression electrum gratings is of great significance. Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem to be solved by the present invention is to provide an electrum diffraction grating for pulse compression and a manufacturing method thereof, which, while ensuring the optical properties of conventional pure gold diffraction gratings, expands the frequency band of high diffraction efficiency of the diffraction grating, improves or solves the problem of susceptibility to oxidation of pure silver diffraction gratings, and further improves the laser-induced damage threshold of gold diffraction gratings, and is therefore of great scientific, economic and practical value. [Means for solving the problem]

[0007] The technical solution of the present invention is as follows: In one aspect, the present invention provides an electrum diffraction grating for pulse compression, wherein the diffraction grating metal layer is a metal film having gold on top and silver on the bottom, or a binary mixture film or multi-component mixture film in which gold is blended with other metals, or a metal film having gold on top and a single-component or multi-component mixture of other metals other than gold on the bottom.

[0008] Furthermore, the metal film having gold on the top and silver on the bottom is formed by plating a thin film of pure silver onto a diffraction grating mask, and then plating a thin film of pure gold onto the thin film of pure silver.

[0009] Furthermore, the binary mixture film is a binary alloy film in which silver is mixed with gold, a binary alloy film in which copper is mixed with gold, or a binary alloy film in which a platinum group metal (platinum, palladium, iridium, ruthenium, rhodium, osmium) is mixed with gold.

[0010] Furthermore, the binary alloy film in which silver is mixed with gold is obtained by directly plating an alloy film having different content rates of gold and silver atoms onto a diffraction grating mask.

[0011] Furthermore, the multi-component mixture film is a ternary mixture film in which gold is blended with iridium and platinum, or a multi-component mixture film in which gold is blended with silver, iridium and platinum.

[0012] In another aspect, the present invention also provides a method for producing a medicament for the treatment of a pulmonary arthritis. 1) designing an electrum diffraction grating, The first characteristic profile function of a diffraction grating is h(x)=max{0,H[1-|sin(π(x / (d·f)))|] σ} and The second characteristic profile function of the diffraction grating is h(x)=max{0,H[1-|2(x / (d·f))|] σ} and where h is the depth of the grating profile in the vertical direction, x is the length of the grating in the horizontal direction, H is the maximum groove depth, d is the grating period, f is the grating duty ratio, and σ is the shape factor of the grating profile; The feature function 1 and the feature function 2 are both suitable for simulating actual diffraction grating profiles, and when the above parameters are the same, the feature function 1 is suitable for simulating a situation where the diffraction grating has an S-shaped transition from the top to the bottom of the ridge or a situation where the top is flat, and the feature function 2 is suitable for simulating a situation where the diffraction grating has a truncated bottom of the ridge, a situation where the sidewalls protrude outward, or a situation where the top is sharp; According to needs, select an optimized initial wavelength, select a characteristic profile function of the diffraction grating, and determine the best groove depth, period, duty ratio and shape factor of the diffraction grating that achieves high diffraction efficiency within a specific spectral bandwidth through a global optimization or local optimization algorithm; 2) A step of fabricating an electrum diffraction grating mask, which includes cleaning the substrate, applying a photoresist, baking, exposing, and developing the photoresist to produce the diffraction grating designed in step 1; 3) plating an electrum layer, Using manufacturing processes such as magnetron sputtering and electron beam evaporation, we plate an electrum film with gold on top and silver on the bottom, or we use dual-source multi-component plating technology to create a binary or multi-component alloy film in which gold is mixed with silver or other metals. By adjusting parameters such as base vacuum, power, gas flow rate, operating pressure, and plating speed, electrum films with different composition ratios were fabricated. Test the film thickness, roughness and element content of the electrum film. Using magnetron sputtering plating technology, the base vacuum for Au and Ag plating is 1x10 -3 ~8×10 -4and adjusting the pressure to 0.3 Pa, the argon gas flow rate to 40-50 sccm, the power to 100-600 W, and the operating pressure to 0.3-0.5 Pa, and plating a gold-on-silver metal film and a gold-silver binary alloy film with a total thickness of 50-300 nm on the diffraction grating mask of step 3. 4) A step of screening electrum diffraction gratings, characterized by the optical properties of the manufactured electrum diffraction gratings with different thicknesses of the top and bottom layers, with gold on top and silver on the bottom, or with different element contents, to screen for the electrum diffraction grating with the best properties such as overall reflectance, spectral width, and angular spectral width; 5) A method for manufacturing an electrum diffraction grating for pulse compression is provided, which includes a step of testing the damage characteristics of the electrum diffraction grating by performing a damage test using a single pulse or multiple pulses on the electrum diffraction grating manufactured in step 4 based on ISO 21254. [Effects of the Invention]

[0013] The technical effects of the present invention are as follows: 1) The diffraction grating of the present invention can expand the frequency band of high diffraction efficiency of the diffraction grating and further improve the laser-induced damage threshold of the gold diffraction grating without degrading the optical properties of conventional gold diffraction gratings.

[0014] 2) The diffraction grating of the present invention has high compatibility and can directly replace the gold diffraction gratings used in conventional applications and conditions, improving the safety threshold of gold diffraction gratings for high-power laser devices and ensuring higher output power of the laser devices.

[0015] 3) The diffraction grating of the present invention has stable process parameters, making it possible to manufacture diffraction gratings with meter-level apertures.

[0016] 4) The diffraction grating of the present invention can improve or solve the problem of pure silver diffraction gratings being easily oxidized, and has high environmental resistance and a long service life.

[0017] 5) The diffraction gratings and associated process parameters of the present invention can be utilized in the construction of spectrometers, commercial ultrafast laser devices, and large-scale high peak power laser devices, all of which have significant economic and practical value in the fields of spectrometers, high power lasers, and the like. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a structural schematic diagram of Example 1 of a pulse compression electrum diffraction grating according to the present invention. FIG. [Figure 2] 1 shows the reflectance of the diffraction grating metal layer of Comparative Example 1 of the present invention and Example 1 of the pulse compression electrum diffraction grating. The incident light is TM polarized light, and the incident angle is 62°. [Figure 3] The −1st-order diffraction efficiency of Comparative Example 1 and Example 1. The incident light is TM polarized light, the incident angle is 62°, the ruling density of the diffraction grating is 1400 g / mm, the duty ratio is 0.7, the groove depth is 220 nm, and the shape factor is 3. [Figure 4] 1 shows the probability of damage testing for Comparative Example 1 and Example 1. The central wavelength of the test laser is 925 nm, the bandwidth is 825 to 1025 nm, and the pulse width is 3 ns. [Figure 5] 1A to 1C are structural schematic diagrams of examples 2, 3, and 4 of the electrum diffraction grating for pulse compression of the present invention. [Figure 6] 1 shows the reflectance of the diffraction grating metal layer of Comparative Example 2 and Example 2 of the pulse compression electrum diffraction grating. The incident light is TM polarized light, and the incident angle is 62°. [Figure 7] The −1st-order diffraction efficiency of Comparative Example 2 and Example 2. The incident light is TM polarized light, the incident angle is 50°, the ruling density of the diffraction grating is 1443 g / mm, the duty ratio is 0.7, the groove depth is 200 nm, and the shape factor is 1.8. [Figure 8] 1 shows the probability of damage testing for Comparative Example 2 and Example 2. The central wavelength of the test laser is 925 nm, the bandwidth is 825 to 1025 nm, and the pulse width is 15 fs. [Figure 9] The −1st-order diffraction efficiency of Comparative Example 2 and Example 3. The incident light is TM polarized light, the incident angle is 54°, the ruling density of the diffraction grating is 1480 g / mm, the duty ratio is 0.6, the groove depth is 200 nm, and the shape factor is 2.5. [Figure 10] 1 shows the probability of damage testing for Comparative Example 2 and Example 4. The central wavelength of the test laser is 925 nm, the bandwidth is 825 to 1025 nm, and the pulse width is 15 fs. [Figure 11] The −1st-order diffraction efficiency of Comparative Example 1 and Example 5. The incident light is TM polarized light, the incident wavelength is 920 nm, the ruling density of the diffraction grating is 1400 g / mm, the duty ratio is 0.7, the groove depth is 220 nm, and the shape factor is 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be further explained below with reference to the examples and drawings, but the scope of protection of the present invention is not limited thereto.

[0020] Example 1 An electrum diffraction grating with a gold top and silver bottom, the structure of which is shown in FIG. 1, is fabricated.

[0021] Using magnetron sputtering plating technology, five sets of metal films with a total thickness of 200 nm, each consisting of gold on top and silver on the bottom, were fabricated. The material compositions were 6 nm-Au + 194 nm-Ag, 8 nm-Au + 192 nm-Ag, 10 nm-Au + 190 nm-Ag, 12 nm-Au + 188 nm-Ag, and 15 nm-Au + 185 nm-Ag, respectively. The base vacuum for Au and Ag plating was 8 × 10 -4 The pressure was 0.5 Pa, the argon gas flow rate was 40 sccm, the power was 300 W, the operating pressure was 0.5 Pa, and the sputtering rates were 0.42 s / nm and 0.40 s / nm, respectively.

[0022] Using a diffraction efficiency measurement system, we tested the spectra of the five sets of samples above with TM polarization and the reflectivity of the samples in the frequency band from 500 to 1150 nm at a fixed angle of 62°. As shown in Figure 2, all of the samples with gold on top and silver on the bottom have bandwidths superior to the pure gold sample. The 12 nm-Au + 188 nm-Ag sample has both spectral bandwidth and absolute efficiency superior to the pure gold sample.

[0023] The parameters of the diffraction grating designed in this example were a groove density of 1400 g / mm, a duty ratio of 0.7, a groove depth of 220 nm, and a shape factor of 3. The diffraction grating was fabricated according to the above specifications. The substrate was wiped with alcohol or acetone. Using a spin coater, the substrate was spin-coated at 2800 rpm for 30 seconds to coat a photoresist layer approximately 220 nm thick on the substrate. The substrate was then baked at 100°C for 2 minutes. Next, using a two-beam interference exposure method, the photoresist-coated substrate was exposed to 325 nm light at an exposure power of 50 μW for 200 seconds. The exposed sample was immersed in a 4% sodium hydroxide solution for 50 seconds. Finally, magnetron sputtering was used to obtain an electrum diffraction grating with a thickness of 12 nm-Au + 188 nm-Ag, with a gold top and silver bottom. The diffraction efficiency of the sample was tested in the frequency band from 700 to 1150 nm at a fixed angle of 62°. As shown in Figure 3, compared to a conventional gold diffraction grating, the measured -1st-order diffraction efficiency of the electrum diffraction grating exceeded 90% in the range from 770 to 1150 nm, demonstrating an overall improvement in diffraction efficiency and an extension of the bandwidth by approximately 40 nm toward shorter wavelengths.

[0024] A one-on-one damage threshold test was performed on the sample based on the ISO 21254 standard. As shown in Figure 4, under the test conditions of a test laser with a central wavelength of 925 nm, a bandwidth of 825-1025 nm, and a pulse width of 3 ns, the laser-induced damage threshold of the electrum diffraction grating was improved by approximately 40% compared to that of a pure gold diffraction grating.

[0025] Example 2 A binary mixed electrum diffraction grating in which palladium is blended with gold, the structure of which is shown in FIG. 5, is fabricated.

[0026] Using dual-source magnetron sputtering plating technology, four sets of gold-palladium binary alloy diffraction gratings with a total thickness of 200 nm were fabricated. The gold and palladium contents were 90%-Au+10%-Pd, 50%-Au+50%-Pd, 30%-Au+70%-Pd, and 10%-Au+90%-Pd, respectively. The base vacuum for gold and palladium plating was 1×10 -3 The pressure was 0.3 Pa, the argon gas flow rate was 50 sccm, the power was 500 W, the operating pressure was 0.3 Pa, and the sputtering rates were 0.38 s / nm and 0.36 s / nm, respectively.

[0027] Using a diffraction efficiency measurement system, we tested the spectra of the four sets of samples above with TM polarization and the reflectivity of the samples in the frequency band from 400 to 1100 nm at a fixed angle of 62°. As shown in Figure 6, the gold-top, silver-bottom samples all have bandwidths superior to the pure gold sample. The 10%-Au+90%-Pd sample outperforms the pure gold sample in both spectral bandwidth and absolute efficiency.

[0028] The parameters of the diffraction grating designed in this example were a groove density of 1443 g / mm, a duty ratio of 0.7, a groove depth of 200 nm, and a shape factor of 1.8. The diffraction grating was fabricated according to these specifications. The substrate was wiped with alcohol or acetone. Using a spin coater, the substrate was spin-coated at 2500 rpm for 30 seconds to form a photoresist layer approximately 200 nm thick. The substrate was then baked at 100°C for 2 minutes. Next, using a two-beam interference exposure method, the photoresist-coated substrate was exposed to 325 nm light at 50 μW exposure power for 200 seconds. After exposure, the sample was immersed in a 4% mass fraction sodium hydroxide solution for 65 seconds. Finally, a 10%-Au+90%-Pd electrum diffraction grating with a thickness of 200 nm was obtained using a dual-source magnetron sputtering plating technique.

[0029] The -1st-order diffraction efficiency of the sample was tested in the frequency band from 700 to 1150 nm at a fixed angle of 62°. As shown in Figure 7, the measured -1st-order diffraction efficiency of the electrum diffraction grating exceeds 90% in the range from 773 to 1150 nm. Compared to conventional gold diffraction gratings, the bandwidth is extended by approximately 65 nm toward shorter wavelengths.

[0030] As shown in Figure 8, under the test conditions where the test laser has a central wavelength of 925 nm, a bandwidth of 825–1025 nm, and a pulse width of 15 fs, the laser-induced damage threshold of the electrum grating is improved by approximately 113% compared to the pure gold grating.

[0031] Example 3 A multi-component mixed electrum diffraction grating, whose structure is as shown in FIG. 5, is manufactured by mixing gold with silver and platinum.

[0032] The parameters of the diffraction grating designed in this example were a groove density of 1480 g / mm, a duty ratio of 0.7, a groove depth of 200 nm, and a shape factor of 2.5. The diffraction grating was fabricated according to these specifications. The substrate was wiped with alcohol or acetone. Using a spin coater, the substrate was spin-coated at 2800 rpm for 30 seconds to form a photoresist layer approximately 220 nm thick. The substrate was then baked at 100°C for 2 minutes. Next, using a two-beam interference exposure method, the photoresist-coated substrate was exposed to 325 nm light at 50 μW exposure power for 200 seconds. After exposure, the sample was immersed in a 4% sodium hydroxide solution for 90 seconds. Finally, a dual-source magnetron sputtering plating technique was used to obtain an 80%-Au+10%-Ag+10%-Pt electrum diffraction grating, each 200 nm thick.

[0033] The -1st-order diffraction efficiency of the sample was tested in the frequency band from 650 to 1050 nm at a fixed angle of 54°. As shown in Figure 9, the measured -1st-order diffraction efficiency of the electrum diffraction grating exceeds 90% in the range from 720 to 1050 nm. Compared to conventional gold diffraction gratings, the diffraction efficiency of the electrum diffraction grating is generally reduced by less than 1%, but the bandwidth is extended by approximately 40 nm toward shorter wavelengths.

[0034] Example 4 A multi-component mixed electrum diffraction grating, whose structure is shown in FIG. 5, is manufactured by compounding gold with iridium and platinum.

[0035] The parameters of the diffraction grating designed in this example were a groove density of 1480 g / mm, a duty ratio of 0.7, a groove depth of 200 nm, and a shape factor of 2.5. The diffraction grating was fabricated according to these specifications. The substrate was wiped with alcohol or acetone. Using a spin coater, the substrate was spin-coated at 2800 rpm for 30 seconds to form a photoresist layer approximately 220 nm thick. The substrate was then baked at 100°C for 2 minutes. Next, using a two-beam interference exposure method, the photoresist-coated substrate was exposed to 325 nm light at 50 μW exposure power for 200 seconds. After exposure, the sample was immersed in a 4% sodium hydroxide solution for 90 seconds. Finally, a 10%-Au+10%-Ir+80%-Pt electrum diffraction grating with a thickness of 200 nm was obtained using a dual-source magnetron sputtering plating technique.

[0036] As shown in Figure 10, under the test conditions where the test laser has a central wavelength of 925 nm, a bandwidth of 825–1025 nm, and a pulse width of 15 fs, the laser-induced damage threshold of the electrum grating is improved by approximately 25% compared to the pure gold grating.

[0037] Example 5 An electrum diffraction grating is fabricated with a gold top and silver-platinum bottom, the structure of which is shown in FIG.

[0038] The parameters of the diffraction grating designed in this example were a groove density of 1400 g / mm, and the manufacturing process and parameters were consistent with those in Example 1. Finally, magnetron sputtering was used to plate the grating to obtain an electrum diffraction grating with a thickness of 10 nm-Au + 190 nm-(90%-Ag + 10%-Pt). The diffraction efficiency of the sample was tested at a fixed wavelength of 920 nm from 50 to 70°. As shown in Figure 11, the measured -1st-order diffraction efficiency of the electrum diffraction grating was higher than that of a conventional gold diffraction grating within the test angle range.

[0039] (Comparative Example 1) A pure gold thin film with a total thickness of 200 nm was fabricated using magnetron sputtering plating technology. The base vacuum for Au plating was 8 × 10 -4 The pressure was 0.5 Pa, the argon gas flow rate was 40 sccm, the power was 300 W, the operating pressure was 0.5 Pa, and the sputtering rate was 0.42 s / nm, respectively.

[0040] Using a diffraction efficiency measurement system, the spectrum of the above sample was tested with TM polarization and the reflectivity of the sample in the frequency band from 500 to 1150 nm was tested at a fixed angle of 62°. The results are shown in Figure 2.

[0041] The grating of this comparative example had a groove density of 1400 g / mm, and the manufacturing procedures and parameters were identical to those of Example 1. Finally, a pure gold grating with a thickness of 200 nm was obtained by plating using magnetron sputtering technology. The diffraction efficiency of the sample was tested in the 700-1150 nm frequency band at a fixed angle of 62°. As shown in Figure 3, the gold grating had a -1st-order diffraction efficiency of over 90% in the 805-1150 nm wavelength range.

[0042] A one-on-one damage threshold test was performed on the sample based on the ISO 21254 standard. As shown in Figure 4, under the test conditions where the central wavelength of the test laser was 925 nm, the bandwidth was 825–1025 nm, and the pulse width was 3 ns, the laser-induced damage threshold of the gold diffraction grating was 0.8 J / cm. 2 It was.

[0043] (Comparative Example 2) Magnetron sputtering plating technology is used to produce a thin film with a total thickness of 200 nm and an element content of 100% Au. The base vacuum for Au plating is 1×10 -3 The pressure was 0.3 Pa, the argon gas flow rate was 50 sccm, the power was 500 W, the operating pressure was 0.3 Pa, and the sputtering rate was 0.38 s / nm, respectively.

[0044] Using a diffraction efficiency measurement system, the spectrum and angular spectrum of the above sample were tested with TM polarization, and the reflection of the sample in the frequency band of 400 to 1100 nm was tested at a fixed angle of 62°. The results are shown in Figure 6.

[0045] The gratings of this comparative example had groove densities of 1480 g / mm and 1443 g / mm. The manufacturing procedures and parameters were the same as those in Examples 2 and 4. Finally, a pure gold grating with a thickness of 200 nm was obtained by plating using magnetron sputtering technology.

[0046] The -1st order diffraction efficiency of the 1443 g / mm gold grating is shown in Figure 7, and the -1st order diffraction efficiency of the gold grating in the wavelength range of 883 to 1150 nm is over 90%. The -1st order diffraction efficiency of the 1480 g / mm gold grating is shown in Figure 9, and the -1st order diffraction efficiency of the gold grating in the wavelength range of 760 to 1050 nm is over 90%.

[0047] As shown in Figures 8 and 10, under the test conditions where the central wavelength of the test laser is 925 nm, the bandwidth is 825–1025 nm, and the pulse width is 15 fs, the laser-induced damage threshold of the gold diffraction grating is 0.26 J / cm. 2 It was.

[0048] The above examples are intended to help those skilled in the art to better understand the present invention, but are not intended to limit the present invention in any way. Those skilled in the art may make modifications or equivalent substitutions to the technical solutions of the present invention without departing from the concept of the present invention, all of which fall within the protection scope of the present invention.

Claims

1. An electrum diffraction grating for pulse compression, An electrum diffraction grating for pulse compression, characterized in that the diffraction grating metal layer is a metal film of a single or multi-component mixture on top of gold, or a two-component mixture film or a multi-component mixture film in which other metals are blended with gold.

2. 2. The pulse compression electrum diffraction grating according to claim 1, wherein the gold upper portion and the single-component or multi-component mixture metal film bottom portion include a metal film having a gold upper portion and a silver bottom portion, and a gold upper portion and a single-component or multi-component mixture metal film bottom portion of a metal other than gold.

3. 3. The pulse compression electrum diffraction grating according to claim 2, wherein the metal film having a gold top and a silver bottom is formed by plating a thin film of pure silver onto a diffraction grating mask, and then plating a thin film of pure gold onto the thin film of pure silver.

4. 3. The pulse compression electrum diffraction grating according to claim 2, wherein the upper part of the gold and the bottom part of the metal film of a single element or a multi-element mixture of metals other than gold are formed by plating a single element or multi-element mixture thin film of silver or a platinum group metal onto a diffraction grating mask, and further plating a thin film of pure gold onto the single element or multi-element mixture thin film of silver or a platinum group metal.

5. 2. The pulse compression electrum diffraction grating according to claim 1, wherein the binary mixture film is a binary alloy film in which silver is mixed with gold, a binary alloy film in which aluminum is mixed with gold, a binary alloy film in which copper is mixed with gold, or a binary alloy film in which a platinum group metal (platinum, palladium, iridium, ruthenium, rhodium, or osmium) is mixed with gold.

6. 6. The pulse compression electrum diffraction grating according to claim 5, wherein the binary alloy film in which silver is mixed with gold is formed by directly plating alloy films having different content rates of gold and silver atoms onto a diffraction grating mask.

7. 2. The pulse compression electrum diffraction grating according to claim 1, wherein the multi-component mixture film is a ternary mixture film in which gold is mixed with iridium and platinum, or a multi-component mixture film in which gold is mixed with silver, iridium, and platinum.

8. A method for manufacturing an electrum diffraction grating for pulse compression according to any one of claims 1 to 7, comprising: 1) designing an electrum diffraction grating, The depth function h of the first longitudinal grating profile １ (x) simulates a grating with an S-shaped transition from the top to the bottom of the ridge, or a flat top, and the formula is: h １ (x)=max{0,H[1-|mmm(π (x / (d・f))|] σ } and The depth function h of the second longitudinal grating profile ２ (x) simulates situations where the grating ridge has a truncated bottom, protruding sidewalls, or a sharp top, and the formula is: h ２ (x)=max{0,H[1-|2(x / (d・f))|] σ } and where x is the length of the grating profile in the lateral direction, H is the maximum groove depth, d is the period of the grating, f is the duty ratio of the grating, and σ is the shape factor of the grating profile; selecting a depth function and an initial wavelength of a longitudinal grating profile and determining, by a global or local optimization algorithm, the best grating groove depth, period, duty ratio and shape factor that achieves high diffraction efficiency within a specified spectral bandwidth; 2) A step of preparing a mask plating for an electrum diffraction grating, A step of manufacturing the electrum film diffraction grating designed in step 1) by cleaning the substrate, applying a photoresist, baking, exposing and developing, in which a metal film having a gold top and a silver bottom and a gold-silver binary alloy film with a total thickness of 50 to 300 nm are plated on the diffraction grating mask; 3) plating an electrum layer, Magnetron sputtering and electron beam evaporation were used to achieve a base vacuum of 1×10 for Au and Ag plating. －３ ~8 x 10 －４ Pa, argon gas flow rate is adjusted to 40-50 sccm, power is adjusted to 100-600 W, and operating pressure is adjusted to 0.3-0.5 Pa to prepare electrum films with different composition ratios, and test the film thickness, roughness and element content of the electrum films; 4) A damage characteristic test of the electrum diffraction grating, in which the electrum diffraction grating manufactured in step 3) is subjected to a damage test using a single pulse or a multi-pulse under use conditions; 5) A step of screening electrum diffraction gratings, in which the optical properties of the manufactured electrum diffraction gratings having different thicknesses of the top and bottom layers, or having gold on top and silver on the bottom, or having different element contents are characterized to screen for the electrum diffraction grating with the best overall reflectance, spectral width, and angular spectral width characteristics.

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