WO2022052197A1

WO2022052197A1 - Picometer ruler

Info

Publication number: WO2022052197A1
Application number: PCT/CN2020/120368
Authority: WO
Inventors: 周常河
Original assignee: 中国科学院上海光学精密机械研究所
Priority date: 2020-09-14
Filing date: 2020-10-12
Publication date: 2022-03-17
Also published as: CN112229318A

Abstract

A picometer ruler. The picometer ruler is a picometer-scale metering tool, and is characterized in comprising an interference light field generation mechanism, a precision adjustment platform, and a detector which is in a transmission direction or a reflection direction of an interference light field, wherein the detector is used for recording an interference signal of the interference light field when the motion of the precision adjustment platform is measured, so as to realize picometer metering. The core of the picometer ruler is realizing metering and measurement by means of a picometer-structured light field. The picometer ruler can be used in scenarios, such as picometer photoetching, picometer measurement, picometer imaging and picometer cameras, that need picometer measurement, and is an essential metering tool for developing emerging disciplines such as picometer optical technology, picometer femtosecond optics, picometer attosecond optics, picometer physics, and picometer-scale light-matter interaction.

Description

Pimeter

technical field

The invention relates to a metrology tool, particularly a picometer ruler, which is a picometer to nanometer scale metrology tool, and is applied to various fields such as picometer lithography, picometer imaging and picometer physics.

Background technique

The picometer is a measurement tool on the picometer scale, and is the physical basis for picometer imaging, picometer measurement, and picometer lithography. The measurement of the picometer scale is the frontier of current science and technology, and the development of an advanced picometer scale is the key to solving the picometer measurement today.

Precision optical measurement has always been the frontier and driving force of today's science and technology. The cutting-edge research of optics has entered the field of pico-optics from the existing micro-nano optics. Pico-optics studies the theory, components and applications of pico-scale optics, including pico-optical principles, pico-optical devices, pico-optical measurement technology, and pico-optical applications, among which the pico-meter ruler is the measurement benchmark at the pico-meter scale , is the most critical measurement tool for the application of Pico science and technology.

Because the picometer scale is too small, no physical device such as the picometer has been developed. Using a laser interferometer, since the laser interferometer has various error sources, including: optical, electronic noise, environmental interference, etc., when the laser interferometer is subdivided to the picometer scale, the measurement signal will be particularly sensitive to noise, which makes the laser interference The reliability of the meter for picometer measurements deteriorates. Using laser gravitational wave technology, or using Fabry-Perot cavity measurement technology, it may be possible to obtain picometer-level signals measured at a single point, but it cannot meet the needs of large-scale, high-precision, stable, and reliable picometer measurements. For example, next-generation semiconductor lithography requires a large range of picometers for high-precision measurement and positioning.

Grating-based picometer measurements offer a promising technological path for picometers. We know that during the development of the large-scale grating laser direct writing device, the Massachusetts Institute of Technology invented the nanolithography technology (Nanoruler), in which the periodic measurement of the interference field has reached the picometer level (see Prior Art 1: Chen C G. Beam alignment and image metrology for scanning beam interference lithography: fabricating gratings with nanometer phase accuracy, Ph.D. dissertation, Massachusetts Institute of Technology, 2003). Zhou Changhe's research group from Shanghai Institute of Optics and Mechanics has also achieved picometer-level precision measurement of the interference field period (see Prior Art 2: Applied Optics 57, 4777-4784 (2018)); The scanning reference grating technique has obtained experimental results with long-range picometer accuracy for the double-beam interference field measurement (see Prior Art 3, Applied Optics 58, 2929-2935 (2019)).

We can understand that although the above-mentioned

prior arts

1, 2 or 3 all provide picometer-accurate measurements of the laser interference field period, none of them can be directly applied to picometer-scale measurements of objects. Based on the idea of using the picometer scale difference of different grating periods to realize the picometer device, Zhou Changhe invented the picometer optical comb technology (see the prior art 4, the manufacturing device and manufacturing method of the picometer optical comb and the picometer optical comb, invention patent application number: 201910368137.9), that is, using the difference of the picometer scale of the two gratings to make the openings in each grating period increase or decrease in picometers or nanometers, which provides a solid foundation for previous research on the picometer scale.

The picometer optical comb invented in the prior art 4 does provide picometer scale modulation of grating openings, but cannot be directly used for picometer microscopy measurements. The reasons are as follows: we cannot guarantee to make objects with continuous picometer scale variation, because there is currently no picometer scale modulated photoresist and corresponding developing and fixing technology. It is difficult to realize the picometer microscopic measurement function.

In order to realize the microscopic function at the picometer scale, Zhou Changhe invented the picometer microscope (refer to the prior art 5, picometer microscope, invention patent application number: 201911127409.9), that is, using the picometer structured light field to realize the picometer microscopic measurement, The picometer-structured light field modulation includes the use of wavelength coding, time-domain coding, or structured light to achieve picometer-scale microscopic measurements.

Pico measurement technology (previous technology 1-3), pico optical comb (previous technology 4), pico microscope (previous technology 5) involves pico measurement, pico modulation, pico microscopic imaging, etc. This provides a strong early technical support for the picometer of the present invention, but the prior art 1-5 did not solve the key problem of the picometer, and the picometer is the basis of the picometer measurement. Therefore, it is necessary to invent the picometer. The meter ruler is a picometer-scale measuring device.

SUMMARY OF THE INVENTION

The picometer ruler of the present invention is a picometer-scale measurement tool, and can have various manifestations and traceability methods. For example, a laser interferometer is used to calibrate and trace the source to the laser wavelength; it can pass the picometer scale of different periods of the high-density grating. It can also be obtained by changing the angle between the multiple beams of the picometer optical comb light field to obtain the picometer structured light field; or using different laser wavelengths to provide picometer scale movement of the picometer optical comb light field; Alternatively, the parallel laser direct writing technology of rotating diffractive optical elements, such as Daman gratings, can be used to realize the picometer-scale control of the distance of laser direct writing. The relative movement between the pico-meter structured light field and the pico-meter optical comb or between the two pico-meter optical combs can also be controlled by feedback to provide the function of a pico-meter ruler.

The technical solution of the present invention is as follows

A picometer ruler is a picometer scale measuring tool, which is characterized by including an interference light field generating mechanism, a precision adjustment platform and a detector in the transmission direction or reflection direction of the interference light field, the detector is used for recording and measuring precision adjustment When the platform moves, the interference signal of the interference light field realizes picometer measurement.

The generation mechanism of the interference light field includes an interference beam combining device of the left beam and the right beam, and the interference beam combining device of the left beam and the right beam is a prism pair or a grating with the same density as the interference field. The left beam and the right beam are combined to generate an interference signal; the precise adjustment platform continuously adjusts the angle between the two beams to obtain structured light fields with different picometer scale differences, and the detector records the difference Interferometric field periodic signal of picometer scale difference to realize picometer measurement.

The generation mechanism of the interference light field is formed by the interference of a left beam and two right beams to form a picometer light comb light field, and the precision adjustment platform is used to precisely adjust the one left beam and the two right beams respectively. The included angle can be adjusted from nano-radians to micro-radians, so as to realize the precise adjustment of the picometer scale of the picometer optical comb light field.

The generation mechanism of the interference light field is a left beam and a double beam on the other side of the picometer light comb light field. By adjusting the wavelengths of the left beam and the double beam on the other side, the picometer light comb is realized. The movement of the field on the picometer scale, the detector records the precise interference field signal of the picometer optical comb light field, and realizes picometer measurement.

The generation mechanism of the interference light field uses diffractive optical elements to generate multiple focal points, including a parallel laser direct writing device of Daman grating, and the precision adjustment platform is an electronically controlled precision turntable. The turntable rotates the diffractive optical element slightly, and the rotation angle is controlled in the order of milliradians, and the multiple foci of the diffractive optical element will rotate an angle correspondingly. Scale adjustment, the detector records the precise interference field signal of the laser direct writing optical field spacing, and realizes picometer measurement.

The generation mechanism of the interference light field is that the picometer structured light field is irradiated on the picometer optical comb, and the precise adjustment platform can change the phase retardation, wavelength, angle between the beams, etc. of the incident light of the picometer structured light field. , the relative distance between the picometer structured light field and the picometer optical comb is feedback-controlled, and the detector records the interference field signal of the relative distance between the picometer structured light field and the picometer optical comb to realize picometer measurement.

The generation mechanism of the interference light field uses the picometer optical comb field to make two picometer optical combs, and the distance between the two picometer optical combs is changed through the precise adjustment platform, so as to obtain the periodicity of different widths and intensities. The picometer light field, and then through the periodic feedback control of the relative distance of the picometer light field with different widths and intensities, the detector records the precise interference field signal between the two picometer optical combs to realize picometer measurement .

The detector is a laser interferometer.

The picometer of the present invention has two traceability approaches: one is to trace the source to the laser wavelength, that is, one nanometer of the laser wavelength is subdivided into 1000 parts as the benchmark of picometer measurement; the second is to trace the source based on the laws of physics For example, when the Daman grating laser direct writing grating is used, when the Damman grating is rotated, assuming that the rotation angle is controlled in microradians, the period increment or decrement of the laser direct writing grating can be controlled in the order of picometers.

The technical effect of the present invention is as follows:

The present invention provides a metrological basis on the picometer scale. Through the measurement reference provided by the picometer scale, the movement and positioning of objects at the picometer scale can be determined, and when the picometer light field is used to observe the interaction process of light and matter at the picometer scale, we have a picometer scale reference. Benchmark, observe the optical world at the picometer scale, discover new optical phenomena, principles, and develop their wide range of applications.

The picometer based on the present invention is also beneficial to the development of picometer lithography, picometer measurement, picometer scale linear or nonlinear optical technology, and is beneficial to the development of emerging disciplines such as picometer femtosecond optics and picometer attosecond optics. , widely used in semiconductor lithography, picometer physics, interaction of light and matter at the picometer scale and many other fields.

Description of drawings

Fig. 1 is the schematic diagram of picometer embodiment 1 of the present invention;

2 is a schematic diagram of measurement and calibration in Embodiment 1 of the picometer of the present invention; wherein (a) is a schematic diagram of

double beams

11, 12 interfering to form a holographic grating; (b) a schematic diagram of the combination of

double beams

11, 12 by prism method; (c) is a schematic diagram of combining the

double beams

11 and 12 by the grating method. (d) Schematic diagram of measuring the period of the holographic grating with a laser interferometer;

3 is a schematic diagram of Embodiment 2 of the picometer of the present invention, wherein (a) is one of the above-mentioned precision adjustment platforms, the mirror 31a and the mirror 32a have a moving amount ΔX ₁ , and (b) is the above-mentioned The second precision adjustment platform is a module that produces double beams with a certain angle. (c) is the picometer comb light field formed by the interference of

light beams

31c, 32c, 33c;

Fig. 4 is the schematic diagram of picometer embodiment 3 of the present invention;

Fig. 5 is the schematic diagram of picometer embodiment 4 of the present invention;

6 is a schematic diagram of Embodiment 5 of the picometer of the present invention, wherein (a) the mirror 31a and the mirror 32a have a movement amount ΔX ₁ , and (b) there are double beams with a certain angle;

Fig. 7 is the schematic diagram of embodiment 6 of the picometer of the present invention

Figure 8 is a schematic diagram of Embodiment 7 of the picometer ruler of the present invention, wherein (a)

laser beams

74, 75, 76 are used to generate a picometer comb light field for

manufacturing picometer combs

88, 89, (b) picometer combs 88 and the picometer comb 89 are complementary to each other, and (c) the picometer comb 88 and the picometer comb 89 move each other by X=d.

detailed description

The present invention will be further described below with reference to the accompanying drawings and embodiments, but the protection scope of the present invention should not be limited by this.

Please refer to FIG. 1 first. FIG. 1 is a schematic diagram of Embodiment 1 of the picometer of the present invention. As can be seen from the figure, the picometer of the present invention includes an interference light field generating mechanism, a precision adjustment platform and a detector in the transmission direction or reflection direction of the interference light field. An

interference field

15, 16, 17 is formed, and this interference field is measured by a laser interferometer 18 to form picometers 19 of different lengths. There is an included angle between the left light beam 11 and the right light beam 12 of the two-beam holography, and this included angle determines the size of the holographic fringe period d. The right beam 12 reaches the position of the holographic beam 13 after being rotated by an angle θ _N through the precision adjustment platform, and the period d of the interference field also changes by Δd _N . This change Δd _N is accurately measured by the laser interferometer 18. Specifically The measurement process can refer to the prior art 3. Since the holographic interference field can be accurately measured to the picometer level, different holographic grating period values (d+Δd ₁ ), (d+Δd _N ), etc. can be obtained by rotating different angles θ _N , so as to realize the picometer level. The benchmark of the ruler.

For example, the period of the interference field formed by the left beam 11 and the right beam 12 at time t ₁ is (d+Δd ₁ ); the period of the interference field formed by the left beam 11 and the right beam 13 at time t _N is (d+Δd _N ). Since the angle θ _N can take any value, Δd ₁ , Δd ₂ , Δd _N can obtain any value with picometer precision. For an interference field with period d=833nm, the difference between the two gratings can be Δd ₁ =10pm,Δd ₂ =20pm,...,Δd _N =1000pm; combining all these picometer-accurate variations , the picometer 19 as shown in Figure 1 can be obtained, which can be used as the basis for the measurement of the picometer scale.

Figure 2(a) is a schematic diagram of the holographic grating formed by the interference of the

double beams

11 and 12. The grating period is d, the laser wavelength can be selected as λ=405nm, and the angle between the two beams can be selected so that d=833nm. As shown in Figure 2(a), the grating period is

d=λ/(sinθ ₁ +sinθ ₂ ) (1)

Figure 2(b) is the interference beam combining device of the

double beams

11 and 12, of which 23 is a prism pair, and the thin solid line in the middle is the beam combining surface. The

double beams

11 and 12 pass through the middle beam combining surface to form 11', 12' The combined beam of light forms an interference signal between the two on the detector 25 .

Figure 2(c) is a beam combining device using a grating 24, wherein the period of the grating 24 is exactly the same as the interference period formed by the

double beams

11 and 12, both of which are d. On the -1 diffraction order of the grating 24, a combined Beam signals 11 ′, 12 ′, and the interference signal between them is recorded on the detector 25 .

FIG. 2( d ) is a calibration method of the picometer 20 . 21, ₂₂ , . 28 measured. The interferometric field period picometer measuring device 28 may include a scanning reference grating, a mobile stage, a laser interferometer, etc. The working principle is shown in FIG. 2(b) and FIG. 2(c). Since the measurement accuracy of the movement amount X ₂ of the picometer 20 can be in the nanometer or sub-nanometer level, assuming that the number of cycles for measuring the picometer is N=1000, the measurement accuracy of each cycle can reach picometers or sub-picometers Therefore, the measurement accuracy of the picometer of the present invention can be guaranteed to be in the order of picometers.

Example 2

Fig. 3 is the schematic diagram of picometer embodiment 2 of the present invention

Fig. 3(a) is one of the above-mentioned precision adjustment platforms. The mirror 31a and the mirror 32a have a moving amount ΔX ₁ . The laser interferometer 18 is used with nanometer resolution. If the mirror 31a moves by ΔX ₁ =10nm, the two The distance between the

mirrors

31a and 32a is X ₁ =3mm, then the angular resolution of the reflected light deflection is Δθ ₃ =ΔX ₁ /X ₁ =3.3nrad, which reaches the nanoradian level and satisfies the requirements of FIG. 1 of the present invention. Figure 3(c), Figure 4, Figure 5 requirements for beam polarization angle accuracy.

Figure 3(b) is the second precision adjustment platform, a module that generates double beams with a certain angle. Using the mirror 31b, the half mirror 32b, combined with the part of FIG. 3(a), a Δθ module can be formed, the purpose of which is to generate

double beams

32c, 33c with precise angles.

Figure 3(c) is a schematic diagram of Embodiment 2 of the picometer of the present invention. The picometer comb light field is formed by the interference of

light beams

31c, 32c, and 33c. Part of the interference field is 34c, 35c, and 36c, and the period between them is d+Δd. The width of 35c is ΔX ₃ , and the width of 34c on the left side is 34c. For ΔX ₃ -Δd, the width of the right side 36c is ΔX ₃ +Δd, since Δd can be set by the angle Δθ ₃ between the

beams

32c, 33c, so that Δd can be continuously selected from 10pm-1000pm, or larger to nanometers magnitude.

The specific embodiment of Fig. 3(c) may be, the period of the picometer comb is d=833nm, Δd=100pm, the width of 35c is ΔX ₃ =300nm; the width of 36c is ΔX ₃ +Δd=300nm+100pm=300.100nm; 34c The width of ΔX ₃ -Δd=300nm-100pm=299.900nm. Therefore, the fixed picometer scale difference between 34c, 35c, 36c can be used as a case of the picometer embodiment.

Example 3

Fig. 4 is the embodiment 3 of the picometer of the present invention. The light beam 41 is the left light beam of the interference light field, and the light beams 42 and 43 are the two right light beams of the interference light field. When the two

right beams

42 and 43 are rotated by an angle Δθ ₄ to the position of 43 and 44 under the adjustment of the precise adjustment platform, the light field 47 of the picometer structure will move to the position of 48 . Since the structure of FIG. 3(a) or FIG. 3(b) is adopted, the rotation angle _Δθ4 can be controlled in the order of nanoradians to microradians according to the needs. Therefore, the movement of the light fields 47 to 48 of the picometer structure can be controlled in the order of picometers. Meter scale, which is also an example of a picometer.

Example 4

Figure 5 is Example 4 of a picometer. The right beams 51, 52, and the left beams 53, 54 of different wavelengths form interference fields 55, 56, 57, wherein the beams 51, 53 are beams of the same wavelength _λ1 , and 52, 54 are beams of the same wavelength _λ2 . From Figure 2(a) and formula (1), we know that the spacing X5 between the interference structures ₅₅ , 56, 57 is proportional to the wavelength λ of the laser used, as shown in 58, therefore, when the wavelengths 51, 53 are used When λ ₁ becomes 52, the wavelength λ ₂ of 54, its interference structure 56 will move to 57. Controlling the choice of wavelength, values of X5 in the order of picometers can be achieved, eg, _X5 = _100pm .

Example 5

Figure 6 is Example 5 of a picometer. As shown in FIG. 6( a ), 61 is the incident laser beam used, and 62 is a diffractive optical element such as a Damman grating or the like. 63 is the diffraction distribution of the incident laser light 61 after passing through the diffractive

optical element

62, 64 is a focusing lens, which focuses the multiple beams generated by the diffractive optical element 62, for example, a Daman grating on the focal plane to form multiple foci, 66, 67, 68 etc. When the diffractive optical element 62 is rotated by an angle θ ₆ under the adjustment of the precise adjustment platform, the multi-focus generated by the diffractive optical element 62 will also rotate by an angle θ ₆ on the focal plane of the lens 64 , and the focus 68 will rotate to the position of 69 . As shown in Fig. 6(b), assuming that the moving directions of the platform are shown as 67b, 68b, and 69b, the focus distance d before rotation will be shortened by a distance Δd. Using a precision electronic turntable, the rotation angle can be precisely controlled to the order of microradians, so Δd can be precisely controlled to the order of picometers, for example, d=833nm, Δd=100pm. Therefore, this is the fifth embodiment of the picometer.

Example 6

Fig. 7 is Embodiment 6 of the picometer of the present invention. 71 is the illumination light, 72 is the focusing lens, 73 is the focused light after passing through the focusing

lens

72, 74 is the left beam for generating the picometer comb light field, 75 and 76 are The combined action of the right beams, 74, 75, and 76 produces a picometer comb light field 78, of which 77 is the light field distribution in one cycle of the picometer comb light field. 79 is a picometer optical comb, on which there are picometer modulation structures such as Δd, 2Δd, 3Δd, etc. For example, 80 is one of the picometer structures, between the picometer light field structure 77 and the picometer structure 80 on the picometer comb light field The relative distance is ΔX ₈ , and the movement of the picometer comb can be expressed as X ₈ . 81 is the light beam after the focused light 73 passes through the picometer light field structure 77 and the picometer light comb structure 80, 82 is the condensing lens, 83 is the condensing beam of the condensing

lens

82, 84 is the imaging point corresponding to the condensing

lens

82, 84 There is a light intensity detector 85 on the detector, and the intensity on this detector is determined by the phase

It is determined by the delay module (indicated by the dotted box), the laser wavelength λ, the included angle θ ₃ between the left and right beams that generate the picometer optical comb light field, and the included angle Δθ ₃ between the two right beams. The laser wavelength can be selected by the Laserλ module, which is used to provide the phase

Incident light for the delay module (indicated by the dashed box) and the Δθ module. By controlling these variables, the function of a picometer can be achieved, eg, ΔX ₈ =100pm.

Example 7

Fig. 8 is the working principle of Embodiment 7 of the picometer of the present invention. Figure 8(a) illustrates the use of

laser beams

74, 75, 76 to generate picometer comb light fields for use in the manufacture of picometer combs 88,89. Fig. 8(b) shows that when the pico-

optical combs

88 and 89 are completely complementary and coincident, under the illumination of the incident light field 86, the light field passing through the two 88, 89 has a light intensity of zero when X=0, I ₈₇ = 0; Figure 8(c) shows that when the picometer comb 88 and the picometer comb 89 move with each other by X=d, since the adjacent structures of the picometer combs differ by Δd, a width will appear in each cycle at this time. In the case of the Δd light field, as shown in 90, 91, and 92, by detecting the picometer

light field

90, 91, and 92, the distance between 88 and 89 can be feedback locked. The process is as follows: 93 is from the picometer structured light field 90 The light is collected by the focusing lens 94 to form a convergent light 95, which is irradiated on the detector 96, and is controlled by the feedback device 97 to control the movement X between the picometer combs 88 and 89 to realize the function of the picometer. When the distance between 88 and 89 is X=N·Δd, there will be a light field with a width of N·Δd picometers in each period. Since the change of the light intensity I ₈₇ is related to the distance between 88 and 89 , and this light intensity value is obtained in the dark field, when the detector is sensitive enough, the resolution of picometer scale can be obtained, for example, Δd=100pm.

The present invention discloses at least seven embodiments of the picometer. These seven picometers can be regarded as two traceability methods. Figures 1 and 2 are traced to the laser wavelength of the laser interferometer 18 from the reference of the picometer scale, that is, one nanometer of the used laser interferometer is subdivided by a thousand times, which is one picometer. Higher subdivision multiples take into account the wavelength stability of the laser interferometer. If the wavelength of the laser interferometer used is accurate and stable after calibration, the picometer subdivision accuracy here is guaranteed. The reference traceability of the picometer in Figure 3(c) is also based on the wavelength of the laser interferometer used, so the difference Δd of the picometer structure is also guaranteed.

Figure 4 is obtained based on the rotation of the angle between the two beams of light that generate the picometer comb light field. Therefore, using the structure of Figure 3(a), (b), the rotation angle can be locked at the nanoradian level, then the picometer structure The moving amount ΔX ₄ of the light field is also controllable, that is, it can be scaled. This calibration can be achieved by theoretical calculation or by experimental comparison. After calibration, it can be actually used as a picometer.

The picometer of Figure 5 can also be used by calibration. Because the laser wavelength λ is proportional to the distance X ₅ of the resulting picometre structure, this calibration can be calibrated both by theoretical calculations and experimental tests. After calibration, it can also be used as a picometer.

The variation Δd of the picometer in Fig. 6 is completely determined by the rotation angle θ _6. The precision electronic turntable provides a micro-radian-level rotation angle accuracy, or the structure shown in Fig. 3(a)(b) can be calibrated by θ ₆ . The range of Δd can be determined. After calibration, it can also be used as a picometer.

FIG. 7 is Embodiment 6 of the picometer ruler of the present invention, the key of which is the measurement technique of the mutual distance ΔX ₈ between the picometer optical comb light field 78 and the picometer optical comb 79 . The pico-meter optical comb structure shown in Figure 7 is the simplest structure among them. As shown in the prior art 4, the pico-meter optical comb has a very rich pico-meter optical field structure, and because there is currently no commercialized pico-meter-resolved photoresist , developer, etc., these factors are combined, the picometer measurement system shown in Figure 7 is extremely challenging, but its realization of the function of the picometer is the most practical. Figure 8 illustrates the use of the picometer comb light field to make picometer combs 88, 89. By using the mutual movement between 88 and 89, periodic picometer light fields 90, 91, 92, etc. can be generated to detect the positions of these light intensities, Feedback control of the distance X between the picometer combs 88 and 89 can realize the function of the picometer.

It is necessary to point out that the early technical basis of these picometers was covered in the prior technologies 1-5, but the prior technologies 1-5 did not involve the core system of the picometer, including the benchmark, traceability, calibration and other aspects of the picometer. application etc. For example, prior art 1-3 discussed the interference field picometer measurement technology, not a separate device, not a picometer; prior art 4 was a picometer comb device, not a picometer; prior art 5 The picometer microscope discussed is the generation and imaging of the picometer structured light field, not the measurement system and technology of the picometer ruler. On the basis of the picometer measurement technology of the prior art 1-5, the present invention introduces the concept of picometer for the first time, clearly defines the picometer and its application, and points out six kinds of embodiments, which is the prior art 1 -5 Innovative content that doesn't exist. According to the principles of the present invention, more embodiments of the picometer can be constructed, which are not all listed here, and the scope of the present invention should not be limited by this.

Experiments show that the picometer of the invention provides a reliable and high signal-to-noise ratio of picometer-scale signals and a rich picometer-structured light field. Through the structured light fields of these picometer rulers, measurement devices for the interaction of light and matter under various picometer structured light fields can be developed, which can be used to observe the interaction between light and matter under the action of various picometer structured light fields. The process allows us to discover new optical principles, phenomena and laws in the picometer world from the perspective of picometer measurement, and develop reliable picometer measurement tools and systems.

The picometer scale of the invention is helpful for the development of picometer imaging, picometer lithography, and picometer scale optical technologies, opens up research directions of emerging disciplines such as picometer femtosecond optics, picometer attosecond optics, etc., and is applied to semiconductor lithography, picometer Physics, the interaction of light and matter at the picometer scale and many other fields.

Claims

A picometer ruler is a measurement tool on a picometer scale, which is characterized by comprising an interference light field generating mechanism, a precision adjustment platform and a detector in the transmission direction or reflection direction of the interference light field, the detector is used for recording measurement precision adjustment When the platform moves, the interference signal of the interference light field realizes picometer measurement.
The picometer according to claim 1, wherein the interference light field generating mechanism comprises an interference beam combining device of the left beam and the right beam, and the interference beam combining device of the left beam and the right beam is a prism Yes, or a grating with the same density as the interference field, the purpose is to combine the left beam and the right beam to generate an interference signal; the precision adjustment platform continuously adjusts the angle between the two beams to obtain different picometer scale differences The structured light field of the value, the detector records the periodic signals of the interference field of the different picometer scale differences, so as to realize picometer measurement.
The picometer ruler according to claim 1, wherein the generation mechanism of the interference light field is formed by the interference of a left beam and two right beams to form a picometer comb light field, and the precision adjustment platform is used to precisely adjust the Adjust the angle between the one left beam and the two right beams, and the adjustment amount is from nano-radian to micro-radian, so as to realize the precise adjustment of the picometer scale of the light field of the picometer optical comb, and the detector records the picometer optical comb The optical field precisely interferes with the field signal to achieve picometer measurement.
The picometer ruler according to claim 1, characterized in that the generation mechanism of the interference light field is a left beam and a double beam on the other side of the picometer comb light field. By adjusting the left beam With the wavelength of the double beam on the other side, the picometer scale movement of the picometer optical comb light field is realized, and the detector records the precise interference field signal of the picometer optical comb light field to realize picometer measurement.
The picometer ruler according to claim 1, wherein the generation mechanism of the interference light field adopts a diffractive optical element to generate a plurality of foci, including a parallel laser direct writing device of a Daman grating, and the precision adjustment platform is The electronically controlled precision turntable is used to rotate the diffractive optical element slightly through the electronically controlled precision turntable, and the rotation angle is controlled in the order of milliradians. The precise turning angle realizes the picometer scale adjustment of the laser direct writing optical field spacing, and the detector records the precise interference field signal of the laser direct writing optical field spacing to realize picometer measurement.
The picometer ruler according to claim 1, wherein the generation mechanism of the interference light field is that the picometer structured light field is irradiated on the picometer optical comb, and the precision adjustment platform is incident by changing the picometer structured light field. The phase retardation, wavelength, angle between beams, etc. of light, feedback control the relative distance between the picometer structured light field and the picometer comb, and the detector records the distance between the picometer structured light field and the picometer comb The relative distance of the interference field signal to achieve picometer measurement.
The picometer ruler according to claim 1, wherein the interference light field generating mechanism utilizes the picometer light field to make two picometer combs, and the two picometer combs are changed through the precise adjustment platform The distance between the picometers of periodic light fields with different widths and intensities is obtained, and then the relative distance is controlled by feedback of the periodic picometer light fields of different widths and intensities, and the detector records the two picometers. The precise interference field signal between the meter-optical combs realizes picometer measurement.
The picometer according to any one of claims 1 to 7, wherein the detector is a laser interferometer.