JP2018084464A - Measurement method, measurement device, optical apparatus manufacturing method, and optical apparatus manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement method, a measurement device, an optical apparatus manufacturing method and an optical apparatus manufacturing device with which it is possible to execute highly accurate calibration easily.SOLUTION: Provided is a measurement method using a measurement device that includes an optical system for guiding light reflected at a surface to be inspected to a sensor and a control unit for measuring the shape of the surface to be inspected on the basis of output from the sensor, comprising: an acquisition step for acquiring a first wavefront that corresponds to each standard from the sensor having received each of lights reflected at a first standard and a second standard having mutually different aspherical shapes; a calculation step for calculating a second wavefront that corresponds to each standard acquired from respective lights reflected at each standard by the sensor on the basis of optical system design information, assuming that the optical system is arranged on the basis of design information; and a change step for changing at least the optical system design information so that a difference between a first and a second wavefront corresponding to each standard is smaller than a prescribed value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a measurement method, a measurement device, a method for manufacturing an optical device, and a device for manufacturing an optical device.

  Conventionally, a method has been proposed in which reflected light from a test surface irradiated with light is measured by a Shack-Hartmann sensor, and the surface shape of the test surface is measured in a non-contact and high-speed manner using the output from the sensor. (See Non-Patent Document 1). This measurement method can measure the shape of the test surface with various design values as compared to an interferometer using a null lens (see Patent Document 1). Compared to a stitching interferometer (see Patent Document 2) and a scanning interferometer (see Patent Document 3) that move a sample during measurement, a stage and length measuring machine that move with high accuracy, and a complicated analysis program Is unnecessary.

  In the measurement method disclosed in Non-Patent Document 1, when the test surface is an aspherical surface, incident light is not irradiated perpendicularly to the test surface, and the ray angle of reflected light from the test surface is incident light. It is different from the ray angle. For this reason, the reflected light is not converted into parallel light by the light receiving portion of the sensor, but is detected as a wavefront greatly deviated from the plane wavefront. Therefore, even if the wavefront of the reflected light is measured by the light receiving portion of the sensor, the wavefront does not directly represent the shape of the test surface as in the Fizeau interferometer.

  In order to calculate the surface shape of the test surface from the measurement wavefront, the position magnification (so-called distortion), which is the ratio between the abscissa of the sensor and the abscissa of the test surface, the ray angle on the sensor surface and the test surface And an angle magnification which is a ratio of the light beam angles at.

  However, the position magnification and the angle magnification are not constant with respect to the distance from the optical axis and have a distribution. Since these distributions change sensitively depending on, for example, an error in the radius of curvature of a lens included in the optical system, an error in the position in the optical axis direction (so-called alignment error), spherical aberration, and the like, it is necessary to calibrate. Patent Documents 4, 5, 6, and 7 disclose a method for calibrating a position magnification distribution.

JP 09-329427 A JP 2004-125768 A Japanese Patent No. 3971747 JP 2000-97663 A Japanese Patent Laid-Open No. 10-281736 JP 2006-133059 A JP 2009-180554 A JP 2012-132682 A

Janhans Pfund, Norbert Lindlein and Johannes Schwider, “NonNull testing of rotationally symmetrical assets: a systematic error assessment,” App. Opt. 40 (2001) p. 439

  In the calibration methods disclosed in Patent Documents 4, 5, and 6, the position magnification distribution is calibrated by moving the surface to be measured by a known amount and detecting the amount of change in the measured value measured by the light receiving unit of the sensor. . For this reason, a stage that moves with high accuracy and a measuring instrument that measures the movement distance with high accuracy are required, and it is difficult to simultaneously calibrate the position magnification and the angle magnification with high accuracy.

  In the calibration method disclosed in Patent Document 7, the position magnification distribution is calibrated by moving some members of the optical system. However, since the calibration is performed using the size of the interference fringe diameter on the light receiving surface as an index, when the test surface is an aspheric surface, the interference fringe pitch becomes too fine to accurately grasp the interference fringe diameter. . Furthermore, it is difficult to calibrate the angular magnification distribution with high accuracy.

  Furthermore, in the method disclosed in Patent Document 8, one aspherical surface having a known shape is used as a prototype, and the shape is calculated by measuring the difference between the test surfaces. Here, if the optical system is in a different state from the design value due to assembly factors or environmental factors during measurement, the error is different from the magnification distribution calculated (designed) by the position magnification distribution and angle magnification distribution due to this error. It is difficult to measure.

  In view of such a problem, an object of the present invention is to provide a measurement method, a measurement device, a method for manufacturing an optical device, and a device for manufacturing an optical device that can easily perform high-precision calibration.

  A measurement method according to an aspect of the present invention includes an optical system that guides light reflected from a test surface to a sensor, and a control unit that measures the shape of the test surface based on an output from the sensor. A measurement method using an apparatus, wherein a first wavefront corresponding to each original device from the sensor that receives light reflected by a first original device and a second original device having different aspherical shapes. Assuming that the optical system is arranged based on design information, the sensor acquires from each light reflected by each original device based on the design information of the optical system. At least the design information of the optical system is changed so that the difference between the first wavefront and the second wavefront corresponding to each original device becomes smaller than a predetermined value and the calculation step for calculating the second wavefront corresponding to each original device Change step to It is characterized in.

  Further, the measurement method as another aspect of the present invention includes an optical system that guides light reflected from the test surface to the sensor, a control unit that measures the shape of the test surface based on an output from the sensor, A measuring method using a measuring device having a first corresponding to each original from the sensor that has received the respective light reflected by the first original and the second original having different aspherical shapes. An acquisition step of acquiring one wavefront, and assuming that the optical system is arranged based on design information, the sensor from each light reflected by each prototype based on the design information of the optical system And calculating a second wavefront corresponding to each original device acquired by at least one member of the optical system based on the first and second wavefronts, and the first or second original. And less of the sensor Also such that each difference in optical arrangement for each prototype of the two members is reduced, and having a changing step of changing the design information of at least the optical system, the.

  According to another aspect of the present invention, there is provided a measuring method that irradiates a test optical system with light emitted from a light source, guides light transmitted through the test optical system to a sensor, and a sensor from the sensor. A first reference optical system and a second reference optical system having different characteristics from each other, wherein the measurement device includes a control unit that measures a transmitted wavefront of the optical system to be measured based on an output. If it is assumed that the acquisition step of acquiring the first wavefront corresponding to each reference optical system from the sensor that has received each light transmitted through the optical system, and the optical system is arranged based on design information, the optical Based on the design information of the system, a calculation step for calculating a second wavefront corresponding to each original device acquired by the sensor from each light transmitted through each reference optical system, and a first step corresponding to each reference optical system And the difference between the second wavefront As smaller than value, and having a changing step of changing the design information of at least the optical system, the.

  According to another aspect of the present invention, there is provided a measuring method that irradiates a test optical system with light emitted from a light source, guides light transmitted through the test optical system to a sensor, and a sensor from the sensor. A first reference optical system and a second reference optical system having different characteristics from each other, wherein the measurement device includes a control unit that measures a transmitted wavefront of the optical system to be measured based on an output. If it is assumed that the acquisition step of acquiring the first wavefront corresponding to each reference optical system from the sensor that has received each light transmitted through the optical system, and the optical system is arranged based on design information, the optical A calculation step for calculating a second wavefront corresponding to each reference optical system acquired by the sensor from each light transmitted through each reference optical system based on design information of the system; and the first and second wavefronts Based on the light At least part of the system, the first or second reference optical system, and at least two of the sensors so that the difference in optical arrangement corresponding to each reference optical system of at least two members is reduced at least And a change step for changing design information of the optical system.

  According to the present invention, it is possible to provide a measuring method, a measuring apparatus, a manufacturing method of an optical instrument, and a manufacturing apparatus of an optical instrument that can easily perform highly accurate calibration.

It is a schematic block diagram of the measuring device which performs the measuring method of Example 1. FIG. It is a block diagram of a sensor. 3 is a flowchart illustrating a measurement method according to the first embodiment. 3 is a flowchart illustrating preprocessing according to the first exemplary embodiment. 3 is a flowchart illustrating a calibration process according to the first embodiment. 3 is a flowchart illustrating measurement processing according to the first embodiment. 3 is a flowchart illustrating analysis processing according to the first exemplary embodiment. 10 is a flowchart illustrating a measurement method according to the third embodiment. 10 is a flowchart illustrating calibration processing during measurement according to the third embodiment. 10 is a flowchart illustrating another calibration process at the time of measurement according to the third embodiment. 10 is a flowchart illustrating preprocessing according to the fourth embodiment. It is a figure for demonstrating the position and angle of a light ray. 10 is a flowchart illustrating a calibration process according to the fourth embodiment. 10 is a flowchart illustrating analysis processing according to the fourth embodiment. 10 is a flowchart illustrating a measurement method according to a fifth embodiment. FIG. 10 is a configuration diagram of an optical apparatus manufacturing apparatus according to a sixth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  Fig.1 (a) is a schematic block diagram of the measuring device 100 which can perform the measuring method of a present Example. The light source 1 is a laser light source that emits monochromatic laser light or a laser diode. The light emitted from the light source 1 is condensed toward the pinhole 3 by the condenser lens 2. The pinhole 3 generates a spherical wave with small aberration. A single mode fiber may be used instead of the pinhole 3. The spherical wave from the pinhole 3 is reflected by the half mirror 4 and converted into convergent light by the light projection lens 5. The convergent light is reflected by the original surfaces 61a and 62a of the two original devices 61 and 62 or the test surface 7a of the test object 7, and is transmitted through the light projecting lens 5, the half mirror 4, and the imaging lens 9. Incident on the sensor 11. The light projection lens 5, the half mirror 4 and the imaging lens 9 constitute an optical system that guides the light reflected by each original surface or the test surface 7 a to the sensor 11. The analysis calculation unit (control unit) 13 is configured by a computer, and functions as a wavefront measurement unit, a wavefront calculation unit, a calibration unit, and a shape calculation unit.

  In the present embodiment, the optical system is calibrated using the original devices (first original device, second original device) 61 and 62 having different aspherical shapes. Both the prototypes 61 and 62 are made with design values different from those of the test object 7. The original surfaces 61a and 62a of the original devices 61 and 62 are accurately measured by a device different from the measuring device 100, for example, a probe-type measuring device, and the analysis calculation unit 13 stores the measured surface shape data. To do.

  Each of the light projecting lens 5 and the imaging lens 9 is composed of a plurality of lens elements. The focal length, the radius of curvature and the diameter of the projection lens 5 and the imaging lens 9 and the magnification of the optical system combining the projection lens 5 and the imaging lens 9 are the diameter (effective diameter) and the radius of curvature of the test surface 7a. It is determined based on the size of the light receiving part of the sensor 11.

  The test object 7 is preferably arranged at a position where the test surface 7a and the sensor conjugate surface coincide on the optical axis. In this case, since the light reflected from the surface 7a to be detected does not overlap on the sensor 11, the sensor 11 can accurately measure the angular distribution of the light beam.

  As shown in FIG. 2A, the sensor 11 includes a microlens array 21 in which a large number of minute condensing lenses are arranged in a matrix, and an image pickup device 22 such as a CCD. -It is called a Hartmann sensor. In the sensor 11, the light beam (light beam) transmitted through the microlens array 21 is collected on the image sensor 22 for each minute condenser lens. The image sensor 22 photoelectrically converts an optical image formed by light rays from the minute condenser lens and outputs an electrical signal. The angle φ of the light beam incident on the image sensor 22 detects the difference Δp between the position of the spot condensed by the minute condenser lens and the position calibrated in advance, for example, the spot position when collimated light is incident. It is demanded. The angle φ of the light beam is expressed by the following equation (1), where f is the distance between the microlens array 21 and the image sensor 22.

φ = atan (Δp / f) (1)
By performing the above processing on all the minute condensing lenses, the angular distribution of light rays incident on the sensor 11 can be calculated using the output from the sensor 11.

  The sensor 11 is not limited to the Shack-Hartmann sensor as long as it can measure the wavefront or the angular distribution of the light beam. For example, as the sensor 11, a shearing interferometer or a Talbot interferometer constituted by a Hartmann plate, the diffraction grating 23 shown in FIG. 2B, and the image sensor 24 may be used.

  When the size (diameter) of the light beam received by the sensor 11 is larger than the light receiving area of the sensor 11, the sensor 11 is moved within the light receiving surface (xy plane) to calculate the angular distribution of the light beam, and the calculated data May be connected to create the entire ray angle distribution.

  Hereinafter, with reference to the flowchart of FIG. 3, a method for measuring the surface shape of the test surface 7a, which is an aspheric shape of the present embodiment, will be described. The measurement method of the present embodiment is executed by the analysis operation unit 13 according to a processing program as a computer program. The processing program may be recorded on a computer-readable recording medium, for example.

  In step S10, the analysis calculation unit 13 performs preprocessing. FIG. 4 is a flowchart showing the preprocessing.

  In step S101, the analysis calculation unit 13 is different from the original device surfaces 61a and 62a measured by a measurement device capable of measuring the shape with high accuracy different from the measurement device 100, for example, a stylus type measurement device. Acquire and save the shape (aspherical shape) data.

  In step S <b> 102, the analysis calculation unit 13 uses the surface shapes of the original device surfaces 61 a and 62 a measured in step S <b> 101 and the design information of the optical system of the measuring device 100 to obtain each wavefront ( Calculated wavefront, second wavefront) Wcal1 and Wcal2 are calculated. That is, when it is assumed that the optical system of the measuring device 100 is arranged based on the design information, the analysis calculation unit 13 determines the sensor 11 based on the surface shapes of the original device surfaces 61a and 62a measured in step S101. Each wavefront obtained from is calculated. The design information of the optical system may include not only the optical arrangement, but also aberrations and assembly errors of the optical system measured in advance, lens surface shape and homogeneity information, refractive index distribution information, and the like. The wavefront can be expressed by, for example, a Zernike function that is an orthogonal function.

  In step S103, the analysis calculation unit 13 calculates the sensitivity necessary for calibration. Specifically, the analysis calculation unit 13 calculates a wavefront acquired on the sensor surface when the surface shape of each original device surface is changed by a minute amount from the design information, and the wavefront and the wavefront calculated in step S102 are calculated. The sensitivity to the surface shape is calculated using the difference from the wavefront. Similarly, the sensitivity with respect to the arrangement in the optical axis direction is calculated by changing the position of each original surface and the imaging lens 9 in the optical axis direction (z-axis direction) by a minute amount from the design information. In addition to the surface shape and the arrangement in the optical axis direction, it is possible to calculate the sensitivity corresponding to changes in the surface spacing, curvature radius, various aberrations, phase distribution, refractive index distribution, homogeneity, and birefringence distribution in the lens. Good. The sensitivity can be expressed by, for example, a Zernike function that is an orthogonal function. In this embodiment, the wavefront is calculated. However, the wavefront may be acquired by moving each original device, the imaging lens 9, and the sensor 11 by the stage and measuring the sensor 11. In this case, it should be noted that a stage error is included when calculating the sensitivity.

  In step S11, the analysis calculation unit 13 performs a calibration process. It is difficult to manufacture an optical system according to design information due to lens processing errors, alignment errors, holding deformation, and the like. Therefore, in this embodiment, in order to accurately grasp the state of the optical system and measure the surface shape with high accuracy, calibration processing is performed along the flow of FIG. FIG. 5 is a flowchart showing the calibration process.

  In step S111, the analysis calculation unit 13 causes the sensor 11 to measure the wavefront (measurement wavefront) Wg1 of the light reflected by the original surface 61a in a state where the original device 61 is installed in the measuring device 100.

  In step S112, the analysis calculation unit 13 causes the sensor 11 to measure the wavefront (measurement wavefront) Wg2 of the light reflected by the original surface 62a in a state where the original device 62 is installed in the measuring device 100.

  In this embodiment, the measurement wavefronts Wg1 and Wg2 measured in steps S111 and S112 are set as the first wavefront. The analysis calculation unit 13 causes the adjusting movement mechanism (not shown) to have a plane (xy plane) orthogonal to the optical axis of each original plane so that the difference between the tilt component and the coma component between the measurement wavefront and the calculated wavefront is sufficiently small. ) And the inclination with respect to the xy plane are adjusted. This adjustment reduces the alignment error of each prototype. The same alignment is performed when measuring the test object 7a.

  In step S113, the analysis calculation unit 13 first calculates the difference ΔWg1 between the measured wavefront Wg1 and the calculated wavefront Wcal1, and the difference ΔWg2 between the measured wavefront Wg2 and the calculated wavefront Wcal2, as shown in the following equation (2). To do. Subsequently, the optical parameters of the optical system are calculated using the sensitivity so that the differences ΔWg1 and ΔWg2 are smaller than predetermined values.

  Here, a method for calculating the optical parameters of the optical system using the sensitivity calculated in the preprocessing will be specifically described. In this embodiment, the spherical component (Z4 term and Z9 term) of the Zernike function is used, and the optical parameters are “error amount from design information of arrangement of original device / lens on optical axis” and “surface shape design”. "Error amount from information" is calculated. The Z4 term component (secondary component) and the Z9 term component (quaternary component) of the spherical components of the differences ΔWg1 and ΔWg2 between the measured wavefront and the calculated wavefront are expressed by the following equation (3).

  Here, ΔWg1_Z4 and ΔWg1_Z9 are the Z4 term component and the Z9 term component of the spherical component of the difference ΔWg1. ΔWg2_Z4 and ΔWg2_Z9 are the Z4 term component and the Z9 term component of the spherical component of the difference ΔWg2. S1 original device_Z4 and S1 original device_Z9 are the sensitivities of the Z4 term component and the Z9 term component of the spherical component of the calculated wavefront when the original device 61 is moved in the optical axis direction. S2 original device_Z4 and S2 original device_Z9 are the sensitivities of the Z4 term component and the Z9 term component of the spherical component of the calculated wavefront when the original device 62 is moved in the optical axis direction. S1 lens_Z4 and S1 lens_Z9 are the sensitivities of the Z4 term component and the Z9 term component of the spherical component of the calculated wavefront when the imaging lens 9 is moved in the optical axis direction with the original device 61 installed. . S2 lens_Z4 and S2 lens_Z9 are the sensitivities of the Z4 term component and the Z9 term component of the spherical component of the calculated wavefront when the imaging lens 9 is moved in the optical axis direction with the original device 62 installed. . The S1 surface shape 1_Z4 and the S1 surface shape 1_Z9 are sensitivities to the surface shape error of one lens (first lens) in the optical system in which the original device 61 is installed. The S2 surface shape 1_Z4 and the S2 surface shape 1_Z9 are the sensitivity to the surface shape error of the first lens in a state where the original device 62 is installed. The S1 surface shape 2_Z4 and the S1 surface shape 2_Z9 are sensitivities to the surface shape error of another lens (second lens) in the optical system in which the original device 61 is installed. The S2 surface shape 2_Z4 and the S2 surface shape 2_Z9 are sensitivities to the surface shape error of the second lens in a state where the original device 62 is installed.

  The analysis calculation unit 13 solves the equation (3) so that the differences ΔWg1 and ΔWg2 are smaller than predetermined values. By doing so, “the amount of error from the design information of the arrangement of the original device / lens on the optical axis” (= the amount of change of the original device / lens arrangement) and “the amount of error from the surface shape design information of the two surfaces” (= Surface shape change amount 1, 2) is calculated.

  The calculated error amount from the design information of the original device and the lens and the error amount from the design information of the surface shape are not necessarily the same as the error amount actually generated in the optical system. However, it is possible to cancel the error generated by the interaction of multiple errors.

  In this embodiment, the optical parameter is calculated using the Z4 term component and the Z9 term component of the spherical component of the difference between the measured wavefront and the calculated wavefront, but the optical parameter is set so that the difference between the measured wavefront and the calculated wavefront becomes smaller than a predetermined value. It is important to calculate the parameters, and the calculation method is not limited to this. For example, the optical parameters may be calculated in consideration of even higher-order spherical components so as to match up to higher-order wavefront differences (smaller than a predetermined amount). By using a lot of information, calibration can be performed with high accuracy.

  Further, in this embodiment, as expressed by the equation (3), the arrangement of the original device and the sensor in the optical axis direction and the surface shape information of the two surfaces were obtained as optical parameters and calibrated. Calibration may be performed using surface shape information of more surfaces. Further, the surface shape of one surface may be expressed by a Zernike function, and higher order spherical components may be used. In addition to the original device and the imaging lens 9, the arrangement of other optical elements in the optical system, surface interval, radius of curvature, surface shape, aberration, phase distribution, refractive index distribution, homogeneity, birefringence distribution, light reception Various optical parameters such as the sensor linearity measurement error amount, the wavelength of the light source, and the amount of each change may be used. When performing calibration using a plurality of optical parameters, it is desirable to select ones having different sensitivities.

  Further, the optical parameter is calculated so that the two wavefront differences ΔWg1 and ΔWg2 are smaller than the predetermined amount by performing ray tracing, instead of calculating the error amount from the design information using the sensitivity based on the equation (3). May be. Further, a method of estimating the most likely optical parameter that can obtain a measurement wavefront in calculation may be used. There are no particular restrictions on the optical parameters to be calculated, the arrangement of the optical elements of the optical system, the surface spacing, the radius of curvature, the aberration, the phase distribution, the refractive index distribution, the homogeneity, the birefringence distribution, the linearity error amount of the measurement wavefront of the light receiving sensor, It may be the wavelength of the light source or the amount of each change. As shown in FIG. 1B, a method of setting a dummy surface 14 and giving an arbitrary phase distribution may be used.

  In the present embodiment, the calibration using two masters has been described. However, more accurate calibration can be performed by using three or more masters. Furthermore, higher accuracy can be achieved by increasing the frequency of the wavefront that matches the measured wavefront and the calculated wavefront, and the number of parameters for calibrating the error of the optical system, but at least expressed by equation (4). So two are necessary.

  In addition, when the difference between the two aspherical shapes of the two prototypes is large, a difference in wavefront sensitivity occurs, and the optical path through the optical system is different, so that a wavefront more reflecting the error of the optical system can be acquired. Therefore, the difference between the central curvatures of the two masters is 0.001 (1 / mm) or more (more preferably 0.10 (1 / mm) or more, or 2.00 (1 / mm). It is preferable that: Further, when the amount of aspheric surface, which is the amount of deviation from the spherical surface, is large, there is a difference in the sensitivity of the wavefront. Therefore, it is preferable that the aspherical amount of each aspherical shape of the two prototypes is 0.05 mm or more. Alternatively, three or more original devices that satisfy the above conditions may be prepared, and two original devices may be selected in accordance with the design value of the test surface 7a at the time of calibration. At this time, it is preferable to select a prototype having a small shape difference from the surface to be measured 7a.

  The spherical component (rotationally symmetric component) can be obtained as described above, but a rotationally asymmetric component such as astigmatism remains in the calculated wavefront. In order to remove the rotationally asymmetric component, the design information of the optical system may be changed based on the output from the sensor 11 before and after the rotation of the original device or the test object around the optical axis. Alternatively, the sensitivity to the rotationally asymmetric component may be calculated in the same manner, and the above relational expression for various Zernike functions may be calculated to obtain a solution in which the two wavefront differences are smaller than a predetermined value for all components. If a solution in which two wavefront differences are smaller than a predetermined value can be obtained for all components, there is no need to rotate the original device or the test surface, and high-accuracy measurement can be performed at high speed.

  In step S114, the analysis calculation unit 13 changes the design information of the optical system based on the optical parameter calculated in step S113. In the new design information that has been changed, an error that has occurred during processing or assembly is used as design information for the optical system after calibration. The design information of the optical system after calibration is not necessarily the same as the error actually generated in the optical system, but the error generated by the interaction of a plurality of errors is canceled and the measurement wavefront obtained from the sensor 11 is calculated. Can be equal to the wavefront. That is, the optical system can be calibrated by the method of this embodiment.

  In the calibration process of the present embodiment, the optical parameter is calculated so that the difference between the measured wavefront and the calculated wavefront is smaller than a predetermined value, but the present invention is not limited to this. For example, the optical parameters may be calculated so that the optical arrangements of the two masters are equal. In this case, optical elements in the optical axis direction corresponding to the respective original apparatus when two original apparatuses are respectively installed, at least a part of members of the optical system, and the respective original apparatuses of at least two members of the sensor 11. What is necessary is just to calculate an optical parameter so that the difference of arrangement | positioning (drive amount) may become small.

  In the calibration process of the present embodiment, the design information of the optical system is changed based on the calculated optical parameters. However, each member may be actually driven using the stage by the calculated driving amount.

  In step S12, the analysis calculation unit 13 executes a measurement process. FIG. 6 is a flowchart showing the measurement process.

  In step S121, the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the test surface 7a in a state where the test object 7 is installed in the measuring device 100. The analysis calculation unit 13 causes an adjustment movement mechanism (not shown) to adjust the position and inclination of the test object 7 so that the difference between the tilt component and the coma component between the measurement wavefront and the calculated wavefront is sufficiently small. Regarding the position in the optical axis direction, the center positions of the original surface 61a (62a) and the surface 7a to be measured are separately measured by an external measuring instrument such as a length measuring device or a displacement meter, and the original surface 61a (62a). The position of the test surface 7a may be adjusted so as to coincide with the position. In this embodiment, since the Shack-Hartmann sensor is used as the sensor 11, the light distribution angle Vs of the reflected light can be measured. The analysis calculation unit 13 stores the measured light distribution angle Vs.

  In step S13, the analysis calculation unit 13 executes an analysis process based on the wavefront information of the test surface 7a measured by the sensor 11 in order to calculate the shape information of the test surface 7a. FIG. 7 is a flowchart showing the analysis process.

  In step S131, the analysis calculation unit 13 performs ray tracing using the optical system design information changed in the calibration process, and determines the ray position on the surface 7a to be detected from the ray position distribution and the ray angle distribution Vs that are held. The ray angle distribution vs is obtained. The shape of the test surface 7a is unknown, but ray tracing may be performed based on the design shape of the test surface 7a.

  In step S132, the analysis calculation unit 13 calculates the shape of the test surface 7a by integration from the light beam position and the light beam angle distribution vs obtained in step S131.

  Thus, in order to perform ray tracing and convert information on the sensor 11 to information on the surface 7a to be examined, it is necessary to incorporate ray tracing software in the measuring device 100. However, by performing ray tracing, high-speed and high-precision measurement is possible. Also, the influence of rotationally asymmetric components can be taken into consideration.

  As described above, by using the measurement method of this embodiment using at least two masters having different aspherical shapes, calibration can be easily performed even when the optical system differs from the design value depending on the assembly and environment. Can do. As a result, the shape of the test surface 7a can be measured at high speed and high accuracy without contact.

  In the present embodiment, the test sample is a lens, but is not limited to a lens, and may be a lens having a shape equivalent to that of a lens, for example, a mold. Moreover, although the present Example demonstrated the case where the to-be-tested surface 7a was a convex aspherical surface, a concave aspherical surface may be sufficient. Even in this case, as shown in FIG. 1C, calibration may be performed using at least two masters 61 and 62. The two masters 61 and 62 preferably have different concave aspheric shapes.

  In Example 1, in the calibration process, “the amount of error from the design information of the arrangement of the original device and the lens on the optical axis” and “the amount of error from the surface shape design information” were calculated simultaneously. In this embodiment, after calculating the former, the latter is calculated. By doing so, a highly accurate calibration result with little variation can be acquired. Since other configurations and processes are the same as those in the first embodiment, detailed description thereof is omitted.

  In this embodiment, paying attention to the spherical component (Z4, 9, 16, 25, 36...) Of the Zernike function, the sensitivity is set so that the differences ΔWg1 and ΔWg2 between the measured wavefront and the calculated wavefront are smaller than a predetermined value. To calculate the optical parameters of the optical system. In the present embodiment, “a value of at least two parameters with a large error in the optical system or a spatially low-order frequency wavefront changing” and “a value with a small error or a spatially high-order frequency in the optical system”. "Values of at least two parameters with which the wavefront changes" are calculated. In this embodiment, after calculating the former, the latter is calculated. By doing so, a highly accurate calibration result with little variation can be acquired. Hereinafter, the former will be described as “the amount of error from the design information of the arrangement of the original device / lens on the optical axis”, and the latter will be described as “the amount of error from the surface shape design information”. Note that parameters with large errors in the optical system or spatially changing low-order frequency wavefronts include the arrangement of the optical elements of the optical system, the surface spacing, the radius of curvature, the linearity measurement error amount of the light receiving sensor, and the light source Is the wavelength. Further, parameters in which an error is small in an optical system or a wavefront of a high-order frequency spatially changes are a surface shape, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution.

  In this embodiment, “the amount of error from the design information of the arrangement of the original device / lens on the optical axis” is the three drive amounts of the imaging lens 9, each original device, and the sensor 11. The “error amount from the surface shape design information” is a surface shape error amount of three lens surfaces of the light projecting lens 5 and the imaging lens 9 each composed of a plurality of lenses.

  In this embodiment, the analysis calculation unit 13 first calculates “an error amount from design information on the arrangement of the original device and the lens on the optical axis”. The Zi ^ 2 term component (i is an integer of 2 to 6) of the spherical component of the difference ΔWg1 and ΔWg2 between the measurement wavefront and the calculated wavefront is expressed by the following equation (5).

  Here, ΔWgi ^ 2_1 and ΔWgi ^ 2_2 (i is an integer of 2 to 6) are the Zi ^ 2 term components of the spherical components of the difference ΔWg1 and the difference ΔWg2, respectively. S_i ^ 2_1_lens and S_i ^ 2_2_lens (i is an integer of 2 to 6) are the spherical components of the calculated wavefront when the imaging lens 9 is moved in the optical axis direction with the original devices 61 and 62 installed, respectively. This is the sensitivity of the Zi ^ 2 component (i is an integer of 2 to 6). S_i ^ 2_1_smp and S_i ^ 2_2_smp (i is an integer of 2 to 6) are respectively Zi ^ 2 term components (i is 2 to 2) of the spherical component of the calculated wavefront when the original devices 61 and 62 are moved in the optical axis direction. (Integer of 6). S_i ^ 2_1_sns and S_i ^ 2_2_sns (i is an integer of 2 to 6) are respectively Zi ^ of the spherical component of the calculated wavefront when the sensor 11 is moved in the optical axis direction with the original devices 61 and 62 installed. The sensitivity of the binomial component (i is an integer of 2 to 6). Mlens, Msmp, and Msns are movement amounts of the imaging lens 9, the original device 61 or the original device 62, and the sensor 11, respectively.

  Equation (5) cannot be solved because there are ten equations for three variables of the amount of movement, but the amount of movement that minimizes the difference between the left side and the right side is calculated using the least square method or SVD (singular value decomposition) method. Use it to find out.

  Next, the analysis calculation unit 13 calculates “the amount of error from the surface shape design information”. The Zi ^ 2 term component (i is an integer of 2 to 6) of the spherical component obtained by subtracting the product of the calculated movement amount and sensitivity from the differences ΔWg1 and ΔWg2 is expressed by the following equation (6). .

  Here, Di ^ 2_1 and Di ^ 2_2 (i is an integer of 2 to 6) are respectively Zi ^ 2 terms of spherical components having values obtained by subtracting the product of the calculated movement amount and sensitivity from the differences ΔWg1 and ΔWg2. It is a component (i is an integer of 2-6). Si ^ 2_1_t_k and Si ^ 2_2_t_k are sensitivities to the surface shape error of the lens surface in a state where the original devices 61 and 62 are installed, respectively. k represents three lens surfaces to be used among the light projecting lens 5 and the imaging lens 9, and is an integer of 1 to 3. t represents a variable of the number of the Zernike function when a surface shape error is added to each lens surface, and is 9 or 16. Gt_k is a coefficient of the Zt term of the lens surface designated by k.

  Similar to Equation (5), the surface shape error that minimizes the difference between the left side and the right side may be obtained using the least square method or the SVD (singular value decomposition) method.

  The calculated error amount from the design information of the original device and the lens and the error amount from the design information of the surface shape are not necessarily the same as the error amount actually generated in the optical system. However, it is possible to cancel the error generated by the interaction of multiple errors.

  In this embodiment, the optical parameter is calculated using the components up to the Z36 term of the spherical component of the difference between the measured wavefront and the calculated wavefront. However, the optical parameter is set so that the difference between the measured wavefront and the calculated wavefront is smaller than a predetermined value. It is important to calculate, and the calculation method is not limited to this. For example, the optical parameters may be calculated in consideration of higher order spherical components so as to match up to higher order wavefront differences (smaller than a predetermined amount). By using a lot of information, calibration can be performed with high accuracy.

  Further, in equation (5), the movement amount of each original device, the imaging lens 9 and the sensor 11 in the optical axis direction is calculated. However, other parameters with large errors, such as linearity measurement errors of the sensor 11 and the light source 1 The wavelength error may be calculated simultaneously.

  In this embodiment, the three movement amounts and the surface shapes of the three surfaces are obtained and calibrated as optical parameters. However, calibration using more than three surface shapes may be performed. Furthermore, one surface shape may be expressed by a Zernike function, and higher-order spherical components may be used. In addition, various optical parameters such as arrangement of other optical elements, surface interval, radius of curvature, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution may be used. When performing calibration using a plurality of optical parameters, it is desirable to select ones having different sensitivities. In addition, when the difference between the two aspherical shapes of the two prototypes is large, a difference in wavefront sensitivity occurs, and the optical path through the optical system is different, so that a wavefront more reflecting the error of the optical system can be acquired. Therefore, it is preferable that the difference between the central curvatures of the two masters is 0.001 (1 / mm) or more. Further, when the amount of aspheric surface, which is the amount of deviation from the spherical surface, is large, there is a difference in the sensitivity of the wavefront. Therefore, it is preferable that the aspherical amount of each aspherical shape of the two prototypes is 0.05 mm or more. Alternatively, three or more original devices that satisfy the above conditions may be prepared, and two original devices may be selected in accordance with the design value of the test surface 7a at the time of calibration. At this time, it is preferable to select a prototype having a small shape difference from the surface to be measured 7a.

  In the present embodiment, the calibration process is executed by dividing it into an initial calibration process (assembly calibration process) and a calibration process during measurement. Since the configuration and processing other than the calibration processing are the same as those in the first embodiment, detailed description thereof is omitted.

  Hereinafter, the measurement method of the present embodiment will be described with reference to the flowchart of FIG. The measurement method of the present embodiment is executed by the analysis operation unit 13 according to a processing program as a computer program. The processing program may be recorded on a computer-readable recording medium, for example.

  As described in the first embodiment, the optical system of the measuring device 100 is not arranged as designed due to environmental factors such as lens processing error, assembly error, test object alignment error, and temperature change. Therefore, high-precision measurement is possible by performing calibration for accurately grasping the state of the optical system.

  In this embodiment, the initial calibration process and the measurement calibration process are executed as calibration processes. In the initial calibration process, error factors that do not change once calibrated, such as lens processing errors and assembly errors, and error factors that change over time are calibrated. In this process, as in the first embodiment, calibration is performed using two prototypes having different known aspheric shapes along the flow of FIG. In the calibration process at the time of measurement, an error factor that changes with each measurement (in a short time) is calibrated, such as an optical system error due to a temperature change caused by an environment or a member in the apparatus. In this process, calibration is performed using a single prototype having a known aspheric shape. In the present embodiment, it is possible to perform measurement with higher accuracy by properly using two calibration processes in accordance with the cause of error and the time axis of change.

  FIG. 9 is a flowchart showing the calibration process during measurement. In order to calculate complicated information such as surface shape and phase distribution, information of at least two or more prototypes is required as in the initial calibration process. However, when correcting an error in the driving amount in the optical axis direction such as a temperature change, it is possible to calibrate only with information of one original device. In this process, one of the two prototypes used in the initial calibration process may be used as the prototype. In this embodiment, the original device 61 is used as the original device.

  In step S <b> 201, the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the original device 61 in a state where the original device 61 is installed in the measurement apparatus 100 in order to obtain the measurement wavefront.

  In step S202, the analysis calculation unit 13 calculates the wavefront (calculated wavefront) of the reflected light from the original device 61 on the sensor surface based on the design information of the optical system changed in the initial calibration process. The analysis calculation unit 13 calculates the optical parameter again so that the measured wavefront acquired in step S201 matches the calculated wavefront (the difference between the wavefronts is smaller than a predetermined value). Since the calibration process at the time of measurement aims to reduce the influence of an error factor that changes in a short time, it is preferable to select a calculated optical parameter that changes in a short time. For example, in order to calibrate a short-term temperature change, the focus component, the surface interval, and the arrangement of the lens, sensor, test object, etc. may be selected.

  In step S203, the analysis calculation unit 13 again changes the optical system design information to the optical parameters calculated in step S202. Therefore, in the design information of the optical system after calibration, in addition to the error factors that are difficult to change such as lens processing errors and assembly errors, error factors that occur during measurement are taken into consideration.

  FIG. 10 is a flowchart showing a measurement time calibration process different from the measurement time calibration process described with reference to FIG. 9. In this calibration process at the time of measurement, in order to reduce the influence of an error factor that changes in a short time, the master and the imaging lens are moved along the optical axis from the result of measuring one master. Similar to the calibration process at the time of measurement in FIG. 9, the master 61 is used as a master.

  In step S211, the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the original device 61 in a state where the original device 61 is installed in the measurement apparatus 100 in order to obtain the measurement wavefront.

  In step S212, the analysis calculation unit 13 calculates the wavefront (calculated wavefront) of the reflected light from the original device 62 on the sensor surface based on the design information of the optical system changed in the initial calibration process. Then, it is determined whether or not the difference between the measured wavefront acquired in step S211 and the calculated wavefront is smaller than a predetermined value. If it is larger than the predetermined value, the process proceeds to step S213. If it is smaller than the predetermined value, the flow ends.

  In step S213, the analysis calculation unit 13 uses the sensitivity calculated in step S103 in FIG. 4 so that the measured wavefront matches the calculated wavefront (the difference between the wavefronts is smaller than a predetermined value). The driving amount of the imaging lens 9 is calculated.

  In step S214, the analysis calculation unit 13 drives the master 61 and the imaging lens 9 based on the drive amount calculated in step S203.

  In the measurement method of the present embodiment, it is possible to correct an error occurring at the time of measurement in real time, and more accurate measurement can be performed. In addition, since the calibration process at the time of measurement can be realized with one original device, the total measurement time can be shortened. In addition, the usability can be improved and the calibration load can be reduced.

  In the first embodiment, the method of calculating the light angle distribution vs and the light position on the test surface 7a from the light angle distribution Vs and the light position distribution measured by the sensor 11 has been described. In the present embodiment, a method for calculating the light beam position and the light beam angle distribution vs on the test surface 7a based on a table of position magnification distribution and angle magnification distribution will be described. By using the magnification change table representing the relative relationship between the test surface 7a and the sensor surface, it is not necessary to install the ray tracing software in the measuring device. The present embodiment is different from the first embodiment only in that a magnification distribution is calculated and a shape of a test surface is obtained from a measurement wavefront.

  FIG. 11 is a flowchart showing the preprocessing of the present embodiment. Since the processes in steps S401, S402, and S404 are the same as those in steps S101 to S103 in FIG. 4 described in the first embodiment, detailed description thereof is omitted.

  In step S403, the analysis calculation unit 13 calculates a position magnification distribution α, an angle magnification distribution β, and a principal ray angle distribution η between the sensor surface and the sensor conjugate surface. The position magnification distribution α and the angle magnification distribution β respectively indicate the positional relationship and the angular relationship of the light rays reflected by the original surface and the design surface of the test surface 7a between the sensor surface and the sensor conjugate surface.

  Specifically, as shown in FIG. 12, the position magnification distribution α is a distance r from the optical axis to the incident position of the light beam on the sensor surface, and from the optical axis to the incident position of the light beam on the sensor conjugate plane. When the distance is R, it is expressed by the following formula (7).

α = R / r (7)
The angular magnification distribution β is expressed by the following formula (8). Here, when each original surface and the test surface 7a which is the design value are tilted by a minute angle, the change in the light reflection angle on the meridional surface on the sensor conjugate surface is ΔV, and the meridional surface on the sensor surface is Let Δv be the change in the light beam incident angle.

β = Δv / ΔV (8)
The principal ray angle distribution η is obtained by performing ray tracing calculation in parallel with the optical axis from the sensor 11 (that is, at a ray angle of 0 ° with respect to the optical axis) using each original surface and the test surface 7a which is a design value. It is an angle distribution of the light ray which injects into each original equipment surface and to-be-tested surface 7a at the time of performing.

  The position magnification distribution α, the angle magnification distribution β, and the chief ray angle distribution η need to be calculated for each design value. In this embodiment, since the design values of each of the original surfaces of the two original devices and the test surface 7a are different, it is necessary to obtain a distribution corresponding to each design value.

  FIG. 13 is a flowchart showing the calibration process of this embodiment. Since the processing of steps S411 to S414 is the same as that of steps S111 to S114 of FIG. 5 described in the first embodiment, detailed description thereof is omitted.

  In step S415, the analysis calculation unit 13 calculates a magnification distribution using the method described in step S403 of FIG. 11 based on the changed optical parameter.

  FIG. 14 is a flowchart showing the analysis processing of this embodiment. Since the process of step S443 is the same process as step S132 of FIG. 7 described in the first embodiment, detailed description thereof is omitted.

  In step S441, the analysis calculation unit 13 calculates the ray angle distribution vs on the sensor conjugate plane from the ray angle distribution Vs measured by the sensor 11 using the following equation (9).

  Subsequently, the analysis calculation unit 13 calculates the light beam position distribution rs on the sensor conjugate plane using the following equation (10).

rs = αs × r (10)
Here, r is the light ray measurement position distribution of the sensor 11. In the Shack-Hartmann sensor, the light ray measurement position distribution r corresponds to the center position of each microlens of the microlens array in the coordinates on the image sensor. In addition, the light ray measurement position distribution r and the light ray position distribution rs are distances from the optical axis expressed by coordinates on the xy plane.

  In step S442, the analysis calculation unit 13 performs a ray tracing calculation using the ray position distribution rs and the ray angle distribution vs, and obtains an intersection rbs with the design surface of the test surface 7a. The intersection rbs indicates a distance from the optical axis expressed by coordinates on the xy plane.

  As described above, by performing conversion using the magnification calibration distribution of the present embodiment, the shape of the test surface can be easily calculated without performing ray tracing.

  In the first to fifth embodiments, the case where the reflected light of the test object is measured has been described, but in this embodiment, the case where the transmitted light of the single lens is measured will be described. As a test object (test optical system), in addition to a single lens, a lens unit in which a plurality of lenses are combined, a single lens immersed in liquid, and a lens applied with matching oil can be similarly measured. FIG. 15 is a schematic configuration diagram of a measurement apparatus (transmitted wavefront measurement apparatus) 200 capable of executing the measurement method of the present embodiment. By using the measuring device 200, the light transmitted through the single lens 70 can be measured.

  In this embodiment, two lenses having different characteristics (for example, aspherical shape) are used as the reference optical systems (generators) 610 and 620 for the calibration process. Each reference optical system is desirably known as a reflection surface, but transmitted wavefront information cannot be known. Therefore, it is desirable to manufacture the reference optical system with high accuracy and to measure the shape, curvature, internal transmittance, decentration, and the like in advance to minimize the uncertainty as much as possible.

  Other components and processes (pre-processing, calibration processing, measurement processing, and analysis processing) are the same as those in the other embodiments, and thus detailed description thereof is omitted.

  With reference to FIG. 16, the manufacturing apparatus of the optical apparatus of a present Example is demonstrated. FIG. 16 is a schematic configuration diagram of an optical apparatus manufacturing apparatus 300. The manufacturing apparatus 300 manufactures an optical apparatus based on the information from the measurement apparatus 100 described in the first to fifth embodiments.

  In FIG. 16, reference numeral 50 denotes a material (raw material) of the test lens, and 301 denotes a manufacturing unit that manufactures the test lens 51 as an optical element by processing the material 50 such as cutting and polishing. The test lens 51 has an aspherical shape.

  The shape of the test lens (test surface) processed by the manufacturing unit 301 is measured using the measurement method described in the first embodiment in the measurement apparatus 100 as the measurement unit. As described in the first embodiment, the measuring apparatus 100 corrects the test surface based on the difference between the measurement data of the surface shape of the test surface and the target data in order to finish the test surface into the target surface shape. The processing amount is calculated and output to the manufacturing unit 301. As a result, correction processing is performed on the test surface by the manufacturing unit 301, and the test lens 51 having the test surface reaching the target surface shape is completed.

  When the test lens 51 is used by being incorporated in an optical device such as a camera or an interchangeable lens, the manufacturing unit 301 may be configured to execute a process of incorporating the test lens into the optical device.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Light source 7a Test surface 9 Imaging lens 11 Sensor 13 Analysis calculation part (control part)
61 1st master 62 62 2nd master 100 Measuring device

Claims (27)

An optical system that guides light reflected from a test surface to a sensor, and a control unit that measures the shape of the test surface based on an output from the sensor,
An acquisition step of acquiring a first wavefront corresponding to each original device from the sensor that has received the respective light reflected by the first original device and the second original device having different aspheric shapes;
When it is assumed that the optical system is arranged based on design information, based on the design information of the optical system, the first corresponding to each master acquired by the sensor from each light reflected by each master. A calculating step for calculating the wavefront of 2;
And a changing step for changing at least the design information of the optical system so that the difference between the first and second wavefronts corresponding to each master is smaller than a predetermined value.   2. The change step according to claim 1, wherein the changing step includes a step of calculating at least two parameters such that a difference between the first and second wavefronts corresponding to each master is smaller than the predetermined value. Measurement method.   The two parameters are the arrangement of the optical elements of the optical system, the surface interval, the radius of curvature, the surface shape, the aberration, the phase distribution, the refractive index distribution, the homogeneity, the birefringence distribution, the linearity measurement error amount of the light receiving sensor, the wavelength of the light source, The measurement method according to claim 2, wherein two of the change amounts are included. The changing step includes
Calculating a first parameter that changes a wavefront of a low-order frequency so that a difference between the first and second wavefronts corresponding to each master is smaller than the predetermined value;
Calculating a second parameter that changes a wavefront of a higher-order frequency based on a difference between the first and second wavefronts corresponding to each master and the first parameter;
The measurement method according to claim 1, further comprising: changing design information of at least the optical system based on the first and second parameters. The first parameter is at least two of the arrangement of the optical elements of the optical system, the surface interval, the radius of curvature, the linearity measurement error amount of the light receiving sensor, and the wavelength of the light source,
The measurement method according to claim 4, wherein the second parameter is at least two of surface shape, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution. An optical system that guides light reflected from a test surface to a sensor, and a control unit that measures the shape of the test surface based on an output from the sensor,
An acquisition step of acquiring a first wavefront corresponding to each original device from the sensor that has received the respective light reflected by the first original device and the second original device having different aspheric shapes;
When it is assumed that the optical system is arranged based on design information, based on the design information of the optical system, the first corresponding to each master acquired by the sensor from each light reflected by each master. A calculating step for calculating the wavefront of 2;
Based on the first and second wavefronts, it corresponds to at least a part of the optical system, the first or second master, and each of the at least two members of the sensor. And a changing step for changing at least the design information of the optical system so as to reduce the difference in optical arrangement.   The measurement method according to claim 1, wherein in the changing step, at least a part of the members of the optical system is driven. After the changing step, obtaining a third wavefront from the sensor that has received the light reflected by the first prototype;
When it is assumed that the optical system is arranged based on the design information changed in the changing step, based on the changed design information of the optical system, the light reflected from the first prototype is A calculation step of calculating a fourth wavefront acquired by the sensor;
Change of design information of the optical system changed so that a difference between the third and fourth wavefronts becomes smaller than a predetermined value, or drive of at least a part of the first master and the optical system The measurement method according to claim 1, further comprising:   9. The measurement method according to claim 1, wherein an aspheric amount of each of the aspheric shapes of the first and second prototypes is 0.05 mm or more.   The measurement method according to any one of claims 1 to 9, wherein a difference between the central curvatures of the first and second masters is 0.001 (1 / mm) or more.   11. The method according to claim 1, further comprising: calculating a shape of the test surface based on an output from the sensor and a relative relationship between the test surface and the sensor. The measuring method according to item 1.   The measurement method according to claim 11, wherein the relative relationship between the test surface and the sensor is acquired based on any one of a position magnification distribution and an angle magnification distribution, or ray tracing.   13. The method according to claim 1, further comprising a step of changing design information of the optical system based on outputs from the sensor before and after rotation when the original device is rotated around an optical axis. The measuring method according to item 1. An optical system that irradiates a test optical system with light emitted from a light source, guides the light transmitted through the test optical system to a sensor, and measures a transmitted wavefront of the test optical system based on an output from the sensor A measuring method using a measuring device having a control unit,
An acquisition step of acquiring a first wavefront corresponding to each reference optical system from the sensor that has received each light transmitted through the first reference optical system and the second reference optical system having different characteristics;
When it is assumed that the optical system is arranged based on design information, it corresponds to each prototype that the sensor acquires from each light transmitted through each reference optical system based on the design information of the optical system. A calculating step for calculating a second wavefront;
And a changing step for changing at least the design information of the optical system so that the difference between the first and second wavefronts corresponding to each reference optical system becomes smaller than a predetermined value.   2. The change step according to claim 1, wherein the changing step includes a step of calculating at least two parameters such that a difference between the first and second wavefronts corresponding to each master is smaller than the predetermined value. Measurement method.   The two parameters are the arrangement of the optical elements of the optical system, the surface interval, the radius of curvature, the surface shape, the aberration, the phase distribution, the refractive index distribution, the homogeneity, the birefringence distribution, the linearity measurement error amount of the light receiving sensor, the wavelength of the light source, The measurement method according to claim 2, wherein two of the change amounts are included. The changing step includes
Calculating a first parameter that changes a wavefront of a low-order frequency so that a difference between the first and second wavefronts corresponding to each reference optical system is smaller than the predetermined value;
Calculating a second parameter that changes a wavefront of a higher-order frequency based on a difference between the first and second wavefronts corresponding to each reference optical system and the first parameter;
The measurement method according to claim 14, further comprising: changing design information of at least the optical system based on the first and second parameters. The first parameter is at least two of the arrangement of the optical elements of the optical system, the surface interval, the radius of curvature, the linearity measurement error amount of the light receiving sensor, and the wavelength of the light source,
The measurement method according to claim 17, wherein the second parameter is at least two of surface shape, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution. An optical system that irradiates a test optical system with light emitted from a light source, guides the light transmitted through the test optical system to a sensor, and measures a transmitted wavefront of the test optical system based on an output from the sensor A measuring method using a measuring device having a control unit,
An acquisition step of acquiring a first wavefront corresponding to each reference optical system from the sensor that has received each light transmitted through the first reference optical system and the second reference optical system having different characteristics;
Assuming that the optical system is arranged based on design information, it corresponds to each reference optical system acquired by the sensor from each light transmitted through each reference optical system based on the design information of the optical system Calculating a second wavefront to perform;
Based on the first and second wavefronts, at least a part of the optical system, the first or second reference optical system, and each reference optical system of at least two members of the sensor And a changing step for changing at least the design information of the optical system so that the difference in the corresponding optical arrangement becomes small.   The measurement method according to claim 14, wherein in the changing step, at least a part of the members of the optical system is driven. After the changing step, obtaining a third wavefront from the sensor that has received the light transmitted through the first reference optical system;
Assuming that the optical system is arranged based on the design information changed in the changing step, based on the changed design information of the optical system, from the light transmitted through the first reference optical system A calculation step of calculating a fourth wavefront acquired by the sensor;
The design information changed by the optical system or the first reference optical system and at least a part of the optical system so that the difference between the third and fourth wavefronts is smaller than a predetermined value. 21. The measurement method according to claim 14, further comprising a step of executing driving.   The method further comprises a step of calculating a transmitted wavefront of the test optical system based on an output from the sensor and a relative relationship between the test optical system and the sensor. The measurement method according to any one of the above.   The measurement method according to claim 22, wherein the relative relationship between the optical system to be tested and the sensor is acquired based on any one of a position magnification distribution and an angle magnification distribution, or ray tracing.   24. The method according to claim 14, further comprising a step of changing design information of the optical system based on an output from the sensor before and after rotation when the reference optical system is rotated around an optical axis. The measurement method according to claim 1.   25. A measuring apparatus capable of executing the measuring method according to any one of claims 1 to 24.   A method for manufacturing an optical device, comprising: manufacturing an optical device including an optical element processed based on the measurement method according to any one of claims 1 to 24. A measuring device according to claim 25;
An optical device manufacturing apparatus, comprising: a manufacturing unit that manufactures an optical device including an optical element processed based on information from the measurement device.