JPS58127133A - Method and apparatus for measuring deformation of wave surface by optical device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION The present invention relates to a measuring device and method capable of measuring wavefront deformations caused by optical devices and in particular by objectives or lenses. These wavefront deformations are primarily related to the transfer function of the coherently illuminated optical device. This measurement is based on the study of the transmission of coherent and sinusoidal light waves through optical devices.

Let us briefly explain the principle of such measurement. In a coherent source, the images of the sinusoidal intensity distribution obtained by the optical device are sinusoidal intensity distributions with the same amplitude but one phase difference. The phase of the sinusoidal distribution image depends on the transmission performance of this optical device. This phase ψ(ri is
The transfer function of a coherently illuminated optical device has a coefficient Δ(
It turns out that it depends on ψ〕.

The coefficient Δ(ψ) characterizes the wavefront deformation caused by the optical device and is itself dependent on the spatial frequency of the light wave.

The definition of the coefficient Δ(ri) is shown in Figure 1. Σ in Figure 1
. represents the reference wavefront, and Σ is the actual wave of light waves transmitted by the optical device.

In the case of a perfect optical system, ie, an optical system without aberrations, the wavefront Σ and the wavefront Σ0 would coincide.

The reference wavefront Σ0 can be defined as a spherical surface centered on the image point AY and tangent to the exit pupil P of this optical device.

Linearity at an angle θ with the axis X indicates the propagation direction of the light wave. This line d intersects the reference wavefront Σ0 at a point, and intersects the actual wavefront Σ at a point J. The algebraic value 7 represents the coefficient Δ(ri).

Given the wavelength λ of a light wave, this optical device has a coefficient of These wavefront deformations are extremely difficult to determine with prior art devices.

SUMMARY OF THE INVENTION The present invention is directed to an apparatus and method that can eliminate these drawbacks. The device according to the invention is a relatively simple device and allows the wavefront deformations caused by the optical device to be directly determined.

More specifically, the present invention includes a light beam emitting device;
A Bragg cell, a source beam transmission device, a detection device,
a phase measuring device, capable of measuring the deformation of the wavefront caused by the optical device, and having at least one lens, the source beam emitting device being capable of emitting primarily monochromatic and coherent light beams; ,
The Bragg cell includes at least one light emitting device.
The original beam transmitting device is capable of receiving two optical beams and, excited by radio waves emitted from a radio frequency generator, emits a reference beam and a measurement beam having different time frequencies, A reference beam and a measurement beam may be transmitted in the direction of the optical device to be inspected, and the detection device transmits the optical signals from the optical device at a frequency equal to the time-frequency difference of the beams emitted from the Bragg cell. and shows the characteristics of the wavefront deformation caused by the optical device.
- converting into an electrical signal with a phase, the phase measuring device converting the phase of the electrical signal emitted from the detection device into an electrical signal corresponding to the radio wave used to excite the Bragg cell; The present invention relates to a device capable of measuring the phase difference between the phase of

In contrast to conventional devices, the device according to the invention allows the wavefront deformation caused by an optical device, which can be a simple lens or an objective, to be determined directly. This omission is performed in a simple #t@ manner. This is because measuring the phase deviation between two electrical signals is a simple measurement and can be performed very accurately. Furthermore, the simplicity of this measurement is due to the use of monochromatic coherent elements.

It is noted that, unlike devices according to the prior art, there are no moving mechanical parts in the device according to the invention.

According to a first embodiment of the device according to the invention, the Bragg cell is excited by two radio waves with different frequencies, so that the main beam is diffracted to produce a reference beam and a measurement beam.

According to a second embodiment of the device according to the invention, the Bragg cell has a device capable of splitting the main beam into a reference beam and a measuring beam, and the Bragg cell is excited by one radio wave to directly transmit and diffract the reference beam. The measurement beam is transmitted by the beam.

In a preferred embodiment of the apparatus according to the invention, the inspection 5 also has a slot 1 in the image plane of the optical device to be inspected. There are also prisms arranged in the form of right triangular pyramids. The prism is capable of reflecting the reference beam and the measurement beam towards the detection device, such that the direction of the reflected reference beam is opposite to the direction of the incident reference beam, and the direction of the reflected measurement beam is opposite to the direction of the incident reference beam. opposite the direction of the measurement beam. When using two radio waves to excite a 5 Bragg cell, the frequency difference between the frequency of one radio wave and the frequency of the other radio wave can be constant. This constant difference causes an electrical signal to be transmitted by the detection device, the phase of which represents the deviation of the wavefront deformation caused by the optical device to be examined compared to the spatial frequency of the optical signal from this optical device. At this time, in order to obtain a phase signal representing the characteristics of the wavefront deformation, this device has a device 6 which integrates the signal from the phase measurement device after the phase measurement device.

In a preferred embodiment of the device according to the invention, the radio frequency generator radiates either at two variable frequencies or at two fixed frequencies.

In a preferred embodiment of the device according to the invention, the device for directing the reference beam and the measuring beam in the direction of both the optical device to be tested has at least one condenser lens and a deflection device.

In another preferred embodiment of the device according to the invention, the device emitting a main beam of monochromatic coherent light can be a laser.

The present invention is characterized in that: 1) at least one monochromatic coherent beam Z is incident on a Bragg cell excited by radio waves emitted by a radio wave generator, thereby emitting a reference beam and a measurement beam having different temporal frequencies; (b) sending the reference beam and measurement beam emitted from the cell to an optical device to be inspected; (c) detecting an optical signal from the optical device to be inspected by a detector;
This optical signal has a frequency equal to the time-frequency difference of the original beams emitted from the Bragg cell, and whose phase converts the characteristics of the wavefront deformation caused by the optical device into an electrical signal. and ) the phase and Bragg of the electrical signal supplied by said detector.
and measuring the phase difference between the phase of a corresponding electrical signal and the radio waves used to excite the cell.

In a first embodiment for carrying out the measuring method according to the invention,
A main light beam is sent to a Bragg cell, which is excited by two radio waves with different frequency frequencies, and diffraction of the main beam generates a reference beam and a measurement beam.

In a second embodiment of the measurement method according to the invention, a reference beam and a measurement beam are sent to a Bragg cell, and this Bragg cell is excited by a radio wave and transmits the reference beam directly and the measurement beam by diffraction. Transmit.

In a preferred embodiment of the measuring method according to the invention, step (b)
Afterwards, the reference and measurement beams from the optical device are reflected by a right-angled pentagonal prism placed in the image plane of the optical device to be inspected, such that the direction of the reflected reference beam is opposite to the direction of the incident reference beam. The direction of the dovetail and reflected Ilj constant beams is opposite to the direction of the incident measurement beam, and then the original signal from the prism is detected by a detector.

When exciting a Bragg cell with two radio waves, the frequency difference between the frequency of one radio wave and the frequency of the other radio wave can be constant.

This constant frequency difference transmits an electrical signal, the phase of which reflects the deviation of the wavefront deformation caused by the optical device to be examined compared to the spatial frequency of the original signal from this optical device. After the step), the signal from the phase measuring device is integrated using an integrator in order to obtain the phase characteristics of the wavefront deformation.

According to another preferred embodiment of the measuring method according to the invention, the frequency of the radio waves is continuously varied by direct operation of the radio wave generator.

According to another preferred embodiment of the measurement method according to the invention, before measuring the wavefront deformation produced by the optical device to be tested, this device is calibrated by determining the phase of the electrical signal from the detector. This assay removes the optical device to be tested and, depending on the embodiment, a slot or a prism or a detector for transmitting the reference and measurement beams emitted from the Bragg cell to the optical device to be tested. This is done by placing it in the image plane of the lens used. In some cases, the condenser lens can be replaced by a deflection device.

The present invention will be explained in detail with reference to examples and drawings. It should be noted that these examples are not intended to be limiting.

0 Detailed description of embodiments of the invention FIG. 2 shows a first embodiment of the device according to the invention.

More specifically, this first embodiment includes a light source 2 and a beam splitter 6. The light source 2 can emit a primary monochromatic coherent light beam 4 of temporal frequency ν0, and this light source can be, for example, a Rede. The beam splitter 6 is able to split the light beam 4 into two light beams, namely a reference beam 8 and a measurement beam 10 .

According to the invention, this device also has a Bragg cell 12. Two light beams enter this Bragg cell. One of them is the measurement beam deflected by the splitter 6, which beam is reflected by a reflector such as 14 and enters the cell. This Bragg cell or acousto-optic cell is made of a quartz crystal coupled to a piezoelectric transducer.

In this embodiment, the Bragg cell is a radio frequency generator 16
is excited by radio waves of frequency f generated by This excited cell 12 transmits the reference beam 8 straight, but diffracts the measurement beam 10. At this time, the temporal frequency of the reference beam 8 is ν0, while the measurement beam 10
The time frequency of is νo+f. Here, f is the excitation frequency of the cell.

Diffraction of the measurement beam 10 is obtained by changing the refractive index of the cell by means of radio waves exciting the cell. The lines shown in the Bragg cell represent the vibrational directions or wavefronts of the crystal through which the measurement beam 10 is diffracted.

The value of the excitation frequency of this cell, and thus of the spatial frequency of this excited wave, can be varied continuously by direct manipulation of the radio frequency generator 16.

The values of this spatial frequency ν are 0 and ν. can vary within a range between. Here, ν. is the optical device 18 to be inspected.
is the cutoff frequency of Here, the optical device may be a simple lens. By varying the excitation frequency of the cell, the entire surface of the optical device 18 can be scanned.

FIG. 6 shows a second embodiment of the device according to the invention.

In this second & further example, as in the previous example, the light d$,
2 and a Bragg cell 12. This light source 2
can emit a primarily monochromatic coherent light beam 4 with a temporal frequency ν0, this light source can be 1, for example a Rede.

In this second embodiment, the Bragg cell 12 directly receives the main light beam 4 and is excited by two radio frequency waves emitted by a radio wave generator 16. One of these radio waves has a constant frequency f. , while the frequency of the other radio waves is f, which can be changed continuously. The excited Bragg cell 12 therefore diffracts the main beam 4 into a first beam 8 which has a temporal frequency ν0 + fO and serves as a reference beam;
A second light beam having a time frequency νo+f'i and serving as the measuring beam 10 can be emitted. Diffraction of the main beam by the Bragg cell is obtained in the same manner as described above.

In this second embodiment, the variable frequency 6f of the radio waves must be within the range of . Here, Δf is the passband of the Bragg cell.

In the two aforementioned embodiments, the device according to the invention also has a condenser lens 20. This lens is the optical device 18
The reference beam 8 emitted from the Bragg cell in the direction of
and a measurement beam 10.

In addition, the lens 20 has a function of the angular properties (angle θ) of the optical device being inspected as a function of the angular properties (angle θ) of the Bragg cell.
the diffraction angle of the light beam).

Furthermore, the device according to the invention has a slot 22. This slot is in the image plane of the optical device being inspected.

Above said slot 22, a sinusoidal interference pattern is created by the two light beams 8 and 10 transmitted by the optics [118]. The two interfering light beams are the reference beam 8
for the time frequency ν0 (Fig. 1) or νo + fo
(Fig. 2) is 4, and the measurement beam 10 has νo+f, so the time frequencies are not the same, so the interference fringes move 4 at the speed of one foot.

The light 16 resulting from the interference fringes moving at a uniform velocity can be detected by a detector 24, such as an optical multiplier. This detector converts this optical signal into an electrical signal, the frequency of which is equal to the difference between the time frequencies of the original beams 8 and 100 reaching the detector, i.e. in case 1 of the first embodiment the frequency fK and, in the case of the second example, f-fo. The phase ψ(ν) of this electrical signal characteristically represents the wavefront deformation caused by the optical device 18. This phase ψ(ν) can be measured by device 26. Device 26 can be, for example, a phase meter. Device 26 compares the phase of the electrical signal obtained by detector 24 with the phase of the electrical signal corresponding to the radio waves emitted by radio frequency generator 16 . The electrical signal corresponding to the radio waves emitted by the generator 16 is produced by an actual generator.

The measurement of the wavefront deformation caused by the optical device is 11
This is done using the method described in ■. However, before measuring all of these variations, this device is It is necessary to verify and adjust the scale. This verification is performed by placing the slot 22 directly in the image plane of the coming lens 20 and measuring the phase change produced by the actual measuring device without placing the optical device to be tested.

FIG. 4 shows a sixth embodiment of the device according to the invention.

This sixth embodiment has a light source 2 and a Bragg cell 12 like the previous embodiments. This light source has a time frequency ν
0 primary monochromatic coherent light beam 4 can be emitted. This light source can be, for example, a laser. Plano 8 cell 12 can receive main light beam 4 .

In this sixth embodiment, the plano cell 12 is excited by two radio waves emitted by the radio wave generator 16. One of these radio waves has a frequency f
o, and the other radio wave has a frequency f. The frequency f can be changed continuously. By diffracting the main beam 4, the Bragg cell 12 excited in this way produces a first beam 8 having a temporal frequency νO"fO and serving as a reference beam 1111, and a temporal frequency νof (IH A second light beam is then produced which serves as the measuring beam 1o.The diffraction of the main beam 4 by the planar cell is obtained in the same manner as in the first embodiment.

The value of the excitation frequency f, and therefore the value of the spatial frequency of the excitation wave, can be determined by directly operating the radio wave generator 16.
Can be changed continuously. This variable frequency f is within the following range.

Here, Δf is the transmission band of the Plack cell.

The device according to the invention also has a light coming lens 2o. This condensing lens directs the reference beam 8 and measurement beam 10 which are emitted by the Bragg cell into an optical device 11.
Transmit in direction 8. As before, the lens 20 has a Bragg angle depending on the angular characteristics of the optical device being tested.
The angular properties of the cell can be adapted.

In this sixth embodiment, the device according to the invention also has a prism 32. This prism is in the form of a triangular pyramid or a right pentagonal pyramid and is placed in the image plane of the optical device 18 to be examined. Prism 32 reflects reference beam 8 and measurement beam 10, with the direction of reference beam 8 reflected by prism 32 being opposite to the direction of the incident reference beam, and the direction of the measurement beam reflected by prism 32 being opposite to the direction of the incident reference beam. The direction is opposite to the direction of the incident measurement beam. Whatever the direction of the incident beam, the direction of the reflected beam will always be opposite to the direction of the incident beam.

The prism 32 can be either a solid glass right triangular pyramid that utilizes the phenomenon of total internal reflection or, as shown, a right pentagonal pyramid cut out of a glass cylindrical block. In the latter case, the hollowed-out right-angled pentagonal pyramid 32a is processed so that the reflectance becomes 100 factors. If lined up, a thin layer of metal will be applied to 42a.

The reference beam and measurement beam reflected in the specular direction pass through the coming lens 20 and the Bragg cell 12 again (principle of retrograde rays). The Bragg cell excited by radio waves with a constant frequency fo and a variable frequency f generates a secondary beam 23 coincident with the main beam 4 by diffraction of the reflected reference beam 8 and measurement beam 10, as described above. arise. This 2
The secondary beam 23 is actually created from two light beams.

That is, one is the reference beam whose time frequency is νo+
2fo, and the other is a measurement beam whose temporal frequency is νo+2f.

These two beams of light from the main beam 4, viz.
After the secondary beam 23 is split by a device 28 consisting of 14 semi-reflectors, this light 16 is produced by a director 24. The detector 24 faces:
It can be composed of photoelectron multiplication/H. The detector 24 converts this optical signal into an electric signal of −1g of frequency equal to the time-frequency difference of the light beams entering this detector, i.e., an electric signal of frequency 2 (“o”). The phase 2ψ(ν) of this electrical signal represents the characteristics of the wavefront deformation caused by the optical device 1B.This phase 2ψ(ν) changes with the temporal frequency ν of the light wave transmitted by the optical device. , then ν is equal to 2(f−fo). This phase 2ψ(ν) can be measured by a device f26. The device 26 can be, for example, a phase meter. As before, the device 26 compares the phase of the electrical signal supplied from the detector 24 with the phase of the electrical signal corresponding to the radio waves emitted from the radio wave generator 16. The electrical signal is
Created by a real generator.

In a sixth embodiment of the device according to the invention, the phase of the electrical signal produced by the detector 24 is twice the phase of the electrical signal produced by the detector in the first and second embodiments of the device. . This is because the reference beam 1 and the measuring beam pass through the inspected optics Wtla twice.

When using the sixth embodiment, measuring the wavefront deformation caused by the optical device is carried out in the same manner as described above. However, before measuring this wavefront deformation, the detector 24
It is necessary to calibrate this device so that the phase of the electrical signal supplied by the optical device is actually at a phase 2ψ(ν) characterizing the optical device being examined. This verification is performed by measuring the phase produced by an actual measuring device when the right-angled pentagonal pyramidal prism 32 is placed directly in the image plane of the condenser lens 20 without placing the optical device to be inspected. In this sixth embodiment, instead of two radio waves being used to excite the Bragg cell, the plano cell receives only the main beam 4 emitted by the light source 2. As in the first embodiment, it is possible to excite the Bragg cell by a single radio wave with a variable frequency f, in which case the cell receives a reference beam 8 and a measurement beam 10.

2 FIGS. 5 and 6 respectively show the fourth part of the device according to the invention.
These are a practical example and a fifth embodiment. These devices, like the devices described above, have a light source 2 that emits a main monochromatic coherent light beam 4 of temporal frequency ν0 and a Bragg cell 12 that receives this main light beam 4. The light source 2 can be, for example, a laser.

In these two embodiments, the planar cell 12 is excited by two radio waves generated by a radio frequency generator 16. The frequency of one of these radio waves is fl, and the frequency of the other radio wave is f2. f2 is fl
is not the same as The Bragg cells excited with these diffract the main beam 4, as described above, and thus have a temporal frequency ν which serves, for example, as a reference beam. A first beam 8 with ten f1 and a second beam with time frequency νO+f2 which serves, for example, as measuring beam 10.
A light beam is generated.

In these two embodiments, the excitation frequencies of the Bragg cells, ie, fl and f2, are constant such that their difference is constant.

In the fourth embodiment shown in FIG. 5, the two frequencies fl and f2 are both nine-dimensional. The values of these excitation frequencies are, i.e., the spatial frequency values of the corresponding excitation waves are:
By directly manipulating the radio frequency generation 616, it can be varied continuously.

The spatial frequency corresponding to each of the two excitation frequencies is O
and ν. It can be varied within the range between. Here, ν
. represents the cutoff frequency of the optical device 18 being tested. The optical device to be examined can be a simple lens. As in the case described above (first embodiment 1), by changing the excitation frequency of the cell, the entire surface of the optical device 18 can be scanned.

In this fourth embodiment, the device according to the invention has a condensing lens 20 by which the reference beam 8 and the measuring beam 10 emitted by the Bragg cell are transmitted in the direction of the optical device 18. nru. With the lens 20,
Depending on the angular properties of the optical device to be tested, the angular properties of the Bragg cell can be matched.

In the fifth embodiment shown in FIG. 6, the two frequencies f1 and f2 are fixed frequencies. As before, the values of these frequencies f1 and f2 are 0 and ν. It's within the range. Here, ν. is the cutoff frequency of optical device 18.

In this fifth embodiment, the device according to the invention comprises a deflection device 21
have. By means of this deflection device, the reference beam 8 and the measuring beam 10 emitted by the Bragg cell are transmitted in the direction of the optical device 18 to be examined. This deflection device can be a one-way device or a two-way device consisting of a rotating mirror deflector, an acousto-optic deflector, etc.

According to the invention, for the two aforementioned embodiments, the difference in the two excitation frequencies, i.e. f2 (this difference is constant), is determined by the difference between the reference beam 8 and the measurement beam 10 from the planar cell 12. an optical device 18 in which the angle θ' between
is selected to be at least 100 times smaller than the value of the aperture angle.

In comparison to other embodiments of the device according to the invention, it is clearly noted that either the light beam 8 or the reference beam 10 can serve as reference beam or measurement beam.

After the light beams 8 and 10 pass through the customary optical device 18, the light beams 8 and 10 produce sinusoidal interference fringes at the slot 22. Slot 22 is within one quadrant of the optical device being inspected.

The slot 22 can be omitted in some cases, especially if the angle θ' is small.

Since the two interfering light beams do not have the same temporal frequency, ie, the beam 80 temporal frequency is v0+fl and the beam 100 temporal frequency is v0+f2, the interference fringes move with a constant speed.

The optical signal resulting from this uniform movement of the interference fringes is collected by a detector 24, such as a photomultiplier. Detector 2
4 converts this optical signal into an electrical signal of a frequency equal to the time-frequency difference of the light beams incident on this detector, ie, a frequency fl-f2. The phase of this -ki signal is
The optical device 18 is compared with the spatial frequency ν of the optical signal from the optical device 18 or 5.
The deviation of the wavefront deformation caused by dv can be measured by a device 26 such as a dv meter.

As before, the device 26 compares the phase of the electrical signal sent from the detector 24 with the phase of the electrical signal corresponding to the radio waves emitted by the radio frequency generator 16. The electrical signal corresponding to the radio waves emitted by the generator 16 is produced by an actual generator.

The device according to the invention also has an integrator 30. This integrator is electrically connected to the measuring device 26 and integrates the signal sent from the device ff26 with respect to the frequency ν, thereby determining the phase characteristic ψ(ν) of the wavefront deformation caused by the optical device. I can be hatched.

Measurements of these wavefront deformations are performed as described above. However, before measuring the wavefront deformation, the phase of the electrical signal sent from the detector 24 is integrated 6, and the phase characteristic ψ(
It is necessary to calibrate this device 1 to ensure that it provides the desired performance. This test is carried out when the detector 24 is arranged within one original of the source lens 2o for the fourth implementation of the device according to the invention, or for the fifth implementation if there is no optical device to be tested. This is done by placing a detector 24 immediately behind the deflection device 21 for the embodiment (FIG. 6) and measuring the phase changes caused by the actual measuring device.

[Brief explanation of drawings]

FIG. 1 is a diagram of the wavefront deformation caused by the optical device; FIG. 2 shows a Bragg cell receiving a measurement beam and a reference beam and the Bragg cell being excited by one radio wave;
A schematic diagram of a first embodiment of the device according to the invention, FIG. 6 shows a Bragg cell excited by two radio waves with different frequencies, the frequency of one radio wave being constant and the frequency of the other radio wave being constant. Schematic diagram of a second implementation U of the device according to the invention, in which the frequency is variable; FIG. FIG. 5 is a schematic diagram of a fourth embodiment of the device according to the invention, in which two radio waves with different frequencies are used, both of which are variable; FIG. 6 is a schematic diagram of a fifth embodiment of the device according to the invention, in which two radio waves are used, both of which have one frequency. 2 Optical beam emitting device 12 Plano cell 20 Optical beam transmitting device 24 Detecting device 26 Phase measuring device β 6 Beam splitting device 22 Slot 32 Prism 14 Reflecting device 30 Integrator 16 Radio wave generator 9 Procedural amendment (self-proposed) December 1, 1980 Mr. Commissioner of the Japan Patent Office 1 Indication of the case 1988 Patent Application No. 195189 2 Title of the invention Method for measuring wavefront deformation using an optical device and measuring device 3 Relationship with the person making the amendment case Patent applicant 4, agent 5, date of amendment order (Showa year, month, day 6), number of inventions increased by amendment 8, content of amendment: engraving of the specification as attached (no change in content) procedural amendment (formality) % formula % 1, Indication of the case Patent Application No. 195189 of 1982 3, Relationship with the case of the person making the amendment Patent applicant address 4, Agent 5, Date of amendment order February 22, 1980 6, The number of inventions will increase due to the amendment 7, the figure to be amended - 5 -, Mitsu, Sae' [I, de, τ - no change) 8,
Contents of the amendment As shown in the attached sheet

Claims (1)

[Claims] (1) (a) At least one Bragg cell excited by radio waves emitted by a radio wave generator.
←) injecting two monochromatic coherent beams, thereby emitting a reference beam and a measurement beam with different temporal frequencies, and sending the reference and measurement beams emitted from the cell to an optical device to be examined. and (c) detecting the optical signal from the optical device to be inspected by a detector, and detecting the optical signal at a frequency equal to the time-frequency difference of the original beams emitted from the Bragg cell and whose phase is converting the phase of the electrical signal provided by the detector into an electrical signal representative of the wavefront deformation characteristics produced by the optical device; and The phase difference between the phase of the corresponding electrical signal? A method for measuring wavefront deformation caused by said optical device. (2. In claim 1, the main light beam is i
Sent to IJ bla bla gurgle, and said black
A measurement method in which a cell is excited by two radio waves with different frequencies and the main beam diffracts to produce the reference and measurement beams. (3) In claim 2, the reference beam and measurement beam are sent to the Bragg cell, and the Bragg cell is excited by a radio wave and the reference beam is directly transmitted and the measurement beam is transmitted to the Bragg cell. A measurement method in which the light is transmitted by diffraction V. (4) Permissible Claims In claim 1, 2 or 6, before measuring the wavefront deformation caused by the optical device to be inspected, the phase of the electrical signal supplied by the detector is determined. A verification of the device is performed by removing the optical device to be tested and using the reference and measurement beams radiated from the Bragg cell to the optical device to be tested. A measurement method in which a slot) Y is placed directly within the image plane of an optical lens. (5) In claim 1, it is stated that (
After the step (b), the reference beam and measurement beam from the optical device are reflected by a prism in the form of a right triangular pyramid placed in the image plane of the optical device, and the reflected reference beam is A measurement method in which the direction and the direction of the reflected measurement beam are opposite to the direction of the incident reference beam and the direction of the incident measurement beam, respectively, and the original signal from the prism is detected by the detector. (6) In claim 5, a main light beam is sent to the Bragg cell, and the Bragg cell is excited by two radio waves having different frequencies, and diffraction of the main beam causes the reference beam to be transmitted to the Bragg cell. and measurement methods in which a measuring beam is generated. In claim 6, the Bragg cell excited by two radio waves generates a secondary beam coincident with the main beam by diffracting the reference beam and measurement beam reflected by the prism. and the secondary beam is separated from the main beam and the secondary beam is sent to the detection device. (8) In claim 5, 6 or 7. In addition to measuring the wavefront deformation caused by the optical device to be tested, the device is calibrated by determining the phase of the electrical signal sent from the detector, and the calibration is performed by determining the phase of the electrical signal sent by the detector. Measurements carried out by placing the prism directly in the image plane of a condenser lens used to transmit the reference and measurement beams emitted from the Bragg cell to the optical device to be removed and inspected. (9) Permissible % In claim 2, the frequency difference between the frequency of one radio wave and the frequency of another radio wave is constant, and this constant frequency difference is used to generate the electrical signal. represents the deviation with respect to the spatial frequency of the optical signal from the optical device of the wavefront deformation produced by the optical device, transmitted by the detector and the phase of the electrical signal to be examined; Signal 2 supplied from the measuring device
A measurement method in which the phase is changed by integrating the wavefront deformation characteristics using a separator. 00)% meter According to claim 9, before measuring the wavefront deformation caused by the optical device to be tested, the device is calibrated by determining the phase of the electrical signal supplied by the detector; The detection is carried out in the image plane of a condenser lens which is used to remove the optical device to be tested and send the reference and measurement beams emanating from the Bragg cell to the optical device to be tested. A measurement method performed by directly placing the instrument. 01) According to claim 9, before measuring the wavefront deformation caused by the optical device to be tested, the device is calibrated by determining the phase of the electrical signal supplied by the detector; The detector is placed behind the deflection device used to remove the optical device to be tested and to send the reference and measurement beams emanating from the Bragg cell to the optical device to be tested. A measurement method performed by directly placing the 0. The measuring method according to claim 1, wherein the frequency of the radio waves can be continuously changed by directly operating the radio wave generator. (13J original beam emitter, Bragg cell,
A device comprising a light beam transmission device, a detection device, a phase measuring device, capable of determining the deformation of the wavefront caused by the optical device, and having at least one lens, said original beam emitting device is capable of emitting a primarily monochromatic coherent light beam, said Bragg cell is capable of receiving at least one beam from said emitting device and is excited by radio waves emitted from a radio frequency generator to have different temporal frequencies. emitting a reference beam and a measurement beam, the optical beam transmission device is capable of transmitting the reference beam and measurement beam emitted from the Bragg cell in the direction of the optical device to be inspected;
The detection device converts the optical signal from the optical device into a phase-dependent electrical signal having a frequency equal to the time-frequency difference of the beams emitted from the Bragg cell and indicative of the wavefront deformation produced by the optical device. The phase measuring device may convert the phase difference between the phase of the electrical signal emitted from the detection device and the phase of the electrical signal corresponding to the radio waves used to excite the Bragg cell. A measuring device that can measure. 17. A measuring device according to claim 16, wherein the black cell is excited by two radio waves of different frequencies t and generates the reference beam and the measurement beam by diffraction of the main beam. (15) Claim 13, further comprising a device 7 capable of splitting the main beam into a reference beam and a measurement beam, and the Bragg cell is excited by one radio wave and directly transmits the reference beam. and transmitting said measuring beam by diffraction. (16) A measuring device according to claim 15, wherein the splitting device includes a beam splitting cube device. (17) In claim 15 or 16, after the splitting device, a measurement beam deflected by the splitting device? A defining device also comprising a device capable of reflecting in the direction of said Bragg cell. (layer) In claim 16, a restraining device comprising a slot tightly arranged in the image plane of the optical device to be inspected. A measuring device, the device for transmitting the reference beam and the measuring beam emitted by the device in the direction of the optical device to be inspected also has at least one condensing lens. a right pentagonal pyramidal prism arranged in the image plane of the optical device to be inspected, the prism being able to reflect the reference beam and the measurement beam towards the detection device; and the reflected reference beam and the direction of the reflected measurement beam are respectively opposite to the direction of the incident reference beam and the direction of the incident measurement beam. 22. A measurement device according to claim 21, wherein the reference beam and the measurement beam are created by diffraction of the main beam. A Bragg cell diffracts the reference beam and measurement beam reflected by the prism to produce a secondary beam coincident with the main beam, and transmits the secondary beam to a detection device. A measuring device having a device for splitting the secondary beam and the main beam. (2. In claim 22, the device for splitting the secondary beam and the main beam has a cow reflector. Measuring device according to claim 20, wherein said device is capable of transmitting said reference beam and measuring beam emitted by said Bragg cell in the direction of an optical device to be inspected, said device comprising at least one condensing lens. (2. In claim 14, the frequency difference between the frequency of one radio wave and the frequency of another radio wave is constant, and the electric signal is changed by the detection device based on the constant frequency difference. , the phase of the electrical signal represents the deviation of the wavefront deformation produced by the optical device to be examined compared to the spatial frequency of the optical signal from the optical device, thereby obtaining a characteristic phase of the wavefront deformation. A measuring device having a device capable of integrating a signal from the phase measuring device after the phase measuring device. (2. In claim 25, the reference beam from the Bragg cell and the measuring beam The difference between the two frequencies is selected such that the angle (θ') formed by the two frequencies is at least 100 times smaller than the aperture angle of the optical device to be tested. (2. In claim 25 or 26, the measuring device in which the radio wave generator emits two variable frequencies. A measuring device in which a radio frequency generator emits two fixed frequencies. A measuring device, said device transmitting in the direction of an optical device, said device comprising at least one condensing lens. A measuring device in which the device transmits data in the direction of the optical device to be inspected, the device having a deflection device (3υ). (34) A measuring device in claim 16, wherein the device for emitting the main monochromatic coherent source beam is a laser. (33) Claim 16, in which the phase measuring device is a measuring device with a phase meter.