CN1431477A - Spot diffraction interferometer for measuring surface shape - Google Patents

Spot diffraction interferometer for measuring surface shape Download PDF

Info

Publication number
CN1431477A
CN1431477A CN 03115412 CN03115412A CN1431477A CN 1431477 A CN1431477 A CN 1431477A CN 03115412 CN03115412 CN 03115412 CN 03115412 A CN03115412 A CN 03115412A CN 1431477 A CN1431477 A CN 1431477A
Authority
CN
China
Prior art keywords
lens
mask layer
reflection
aperture
point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN 03115412
Other languages
Chinese (zh)
Inventor
徐文东
周飞
王阳
张锋
魏劲松
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Optics and Fine Mechanics of CAS
Original Assignee
Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Optics and Fine Mechanics of CAS filed Critical Shanghai Institute of Optics and Fine Mechanics of CAS
Priority to CN 03115412 priority Critical patent/CN1431477A/en
Publication of CN1431477A publication Critical patent/CN1431477A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Instruments For Measurement Of Length By Optical Means (AREA)

Abstract

The interferometer includes the optical part and the data acquisition, process and control parts. The optical part includes the laser, the convergent lens, the lens soaked by the solid coated with super resolving power mask arranged in optical axis in sequence along the traveling direction of the laser beam. The part to be measured is positioned above the optical axis and the image lens is in lower part. The data acquisition, process and control parts include the CCD camera, the computer and the displacement controller. The key technique in the invention is the lens soaked by the soild and the mask with supper resolving power. Thus, the smaller pinhole can be obtained as the ideal light source with spherical wave. The position and size of the pinhole are adjustable, providing high transmittance of light and low requirement for the quality of the light beam.

Description

Detect the point-diffraction interferometer of surface configuration
Technical field:
It is a kind of device of the surface configuration of detection means accurately that the present invention detects relevant with optical surface.Particularly a kind of point-diffraction interferometer that adopts solid to soak into lens and mask layer.
Background technology:
The classic method of detection optical surface (as sphere) quality is to use fizeau interferometer or Tai Man-Green's interferometer.These methods need the reference surface of a reality, and the quality that is to say the surface configuration of a device under test of classic method evaluation is that the desirable reference surface that is considered as with itself and a reality compares.For big optical device, as the catoptron of astronomical telescope, its diameter can reach more than 1 meter, and it almost is impossible producing so big reference surface.And the measuring accuracy of classic method can not surpass the precision of this reference surface, have high-precision lens for requiring, as the lens that litho machine is used, accuracy requirement reaches more than one percent wavelength, producing so high-precision desired reference surface, also is impossible.
Point-diffraction interferometer then provides a kind of feasible solution (referring to Interferometricapparatus and methods for measuring surface topography of a test surface, Gemma, et al.United States Patent:6,344,898).The spherical wave front of pointolite diffraction provides the reference surface that uses in the testing process, thereby avoids using actual reference surface.The key of this method is to produce enough little aperture, so that can be considered as the ideal ball ground roll by the light of aperture, and require aperture to have higher light transmission rate, and so that obtain the spherical wave of certain intensity.Formerly in the technology, adopt method making apertures such as etching, this method is difficult to make desirable aperture, thereby the light wave of its diffraction is desirable spherical wave no longer just also.Will have a strong impact on the accuracy of measurement result like this, and the irradiation hot spot is inadequately little, the aperture light transmission rate is lower, influences accuracy of detection equally.Hot spot is incided also have very big difficulty on the aperture with wavelength magnitude, this has increased the difficulty of instrument assembling, and is repeatable poor, detects the cost height.
Summary of the invention:
The technical problem to be solved in the present invention is to overcome the defective of above-mentioned technology formerly, and a kind of point-diffraction interferometer that detects surface configuration is provided, and this interferometer has the measuring accuracy height, be easy to the advantage assembling and adjust.
The basic design of technical solution problem of the present invention is: adopt solid to soak into lens and mask layer and can produce the desirable spherical wave light source of a kind of littler aperture as point-diffraction interferometer.
The concrete technical solution of the present invention is as follows:
A kind of point-diffraction interferometer that detects surface configuration comprises opticator and data acquisition, processing and control section, it is characterized in that:
Described opticator comprises laser instrument, the solid that along on the optical axis of laser beam working direction, be provided with convergent lens successively, is coated with mask layer soak into lens, place above the optical axis device under test, below be provided with imaging len;
Data acquisition, processing and control section comprise ccd video camera, computing machine and displacement controller;
Its position relation is as follows: this solid soaks into lens and is fixed on this displacement control device, computing machine connects and controls the work of ccd video camera and displacement controller, the laser beam that laser instrument sends is behind convergent lens, its focus drops in the middle of the mask layer of solid infiltration lens one side, form aperture and shine device under test through this aperture, the measuring beam of the surperficial TS reflection of this device under test focuses on the surface of this mask layer, after the reflection of this mask layer, this measuring beam and enter ccd video camera through imaging len together from the reference beam that aperture sends.
Described solid soaks into lens to be made by glass of high refractive index, and described mask layer is the antimony film.
Described displacement control device is a high-precision motor, accepts the instruction of computing machine and moves.
Also be provided with compensator between described aperture and the device under test.
Described compensator can be Homology of Sphere optical device, spheric reflection optical device, aspheric transmitting optical device or aspheric surface reflective optical device.
Also be provided with beam splitter, removable catoptron and stationary mirror between described laser instrument and the convergent lens, the laser beam that laser instrument is launched at first is divided into measuring beam and reference beam by beam splitter, and this measuring beam runs into after by beam splitter reflection after the reflection of stationary mirror by beam splitter reflection to catoptron again; And reference beam arrives removable catoptron by beam splitter, by removable catoptron) reflection after incide catoptron by beam splitter once more.This catoptron reflexes to convergent lens with the reference beam and the measuring beam of above-mentioned incident.
Concrete technique effect of the present invention is: the technology that point-diffraction interferometer of the present invention adopts solid infiltration lens and mask layer to combine, solid are soaked into lens light beam are had good focussing force, and numerical aperture is big, and focal beam spot is little.When the hot spot of diffraction limit shone mask layer, because the nonlinear effect of mask will produce an interim aperture less than launching spot (or scattering center) in hot spot irradiation place, and the aperture size that produces was relevant with launching spot intensity.Solid is soaked into lens combine, promptly on solid infiltration lens, plate one deck mask layer and can produce a kind of littler aperture with mask layer.Solid soaks into lens and has certain visual field, can both well focus on the light beam of certain angle scope, will be lower for the requirement of incident beam, and the facula position that produces can regulate by incident beam, makes the instrument assembling comparatively simple.The aperture that is produced also has adjustable positions, adjustable size, light transmission rate advantages of higher.Thereby can overcome the deficiency of technology formerly, a kind of measuring accuracy height is provided, has been easy to the device of the detection means surface configuration assembling and adjust.
Description of drawings:
Fig. 1 is the point-diffraction interferometer synoptic diagram that the present invention detects surface configuration.
Fig. 2 is that the solid that is coated with mask layer soaks into the lens synoptic diagram.
Fig. 3 is the point-diffraction interferometer synoptic diagram that detects the non-spherical surface shape.
Fig. 4 is the point-diffraction interferometer synoptic diagram of the detection surface configuration of tunable optical path difference
Embodiment:
The present invention is further illustrated below in conjunction with accompanying drawing.
See also Fig. 1 earlier, as seen from the figure, the present invention detects the point-diffraction interferometer of surface configuration, comprises opticator and data acquisition, processing and control section.Opticator comprises laser instrument 1, launches the light beam working direction along laser instrument 1, on optical axis oo, convergent lens 2 is arranged successively, and the solid that is coated with mask layer soaks into lens 3, and there is device under test 4 optical axis oo top, and there is imaging len 6 below;
Data acquisition, processing and control section comprise ccd video camera 5, computing machine 7 and displacement control device 8.
The structure of point-diffraction interferometer of the present invention as shown in Figure 1.Described opticator has laser instrument 1, on the direction optical axis oo that advances along laser instrument 1 emission light beam, convergent lens 2 is arranged, there is the solid that is coated with mask layer to soak into lens 3, the orientation of convergent lens 2 should make its focus drop in the middle of the mask layer 3b of solid infiltration lens 3a one side, so that form aperture 3c.On the spherical wave of small holes 3c outgoing advances direction, above optical axis oo, be placed with device under test 4, the orientation of this device under test 4 should make the surface that is focused on mask layer 3b by the measuring beam of its surperficial TS reflection, reflection through mask layer 3b surface, measuring beam and the reference light that sends from aperture 3c together, imaging len 6 enters ccd video camera 5 through optical axis oo below.The orientation of the picture of imaging len 6 should make its object plane drop on the surperficial TS of device under test 4.
Described data acquisition, processing and control section comprise ccd video camera 5, computing machine 7 and displacement control device 8.Computing machine 7 is connected to ccd video camera 5 and the control solid soaks on the displacement control device 8 of lens 3 positions, solid soak into lens 3 be fixed on displacement control device 8 above.
Described laser instrument 1 can be single wavelength or multiple-wavelength laser.When laser instrument 1 is multiple-wavelength laser, need to add wave filter, export a wavelength at every turn, carry out one-time detection, if desired, detect with another wavelength again, two interference fringes that obtain are compared, just can obtain the surface configuration more information of measured device.
Described convergent lens 2 has big numerical aperture.
The described solid that is coated with mask layer soaks into lens 3 (see figure 2)s, is made up of solid infiltration lens 3a and mask layer 3b.Solid soaks into lens to be made by the glass of high index of refraction.Mask layer 3b adopts the antimony mask, utilizes to change the laser transmittance that causes between the crystalline state of antimony and the amorphous state and undergo mutation and realize aperture 3c.Its surface is coated with the diaphragm of reflex.Mask layer 3b also can be that other have the linear structure optical films that further reduces spot size.Focus among the mask layer 3b when light beam soaks into lens 3a through solid, can form than littler " aperture " 3c of hot spot that does not have rete to produce.
Described lens 6 have the big as far as possible rectification distortion and the ability of aberration.
Described displacement control device 8 can be a high-precision motor.
The present invention has aforesaid structure, and the light beam that sends from laser instrument 1 converges to solid infiltration lens 3a through lens 2, soaks into the mask layer 3b that lens 3a arrives its back through solid again.Beam energy is Gaussian distribution, the mask layer 3b temperature of the middle section of hot spot is higher than its fusing point changes it from the crystalline state to the molten state, because the mask layer 3b of molten state is higher than the transmitance of its crystalline state to the incident light transmitance, can form an aperture 3c less than former spot diameter in launching spot irradiation place like this.Be considered as desirable divergent spherical wave SW by the light wave of aperture 3c diffraction.Ideal ball ground roll SW part wavefront is directly incident on the surperficial TS of device under test 4 as measuring beam.Measuring beam is by the reflection of the surperficial TS of device under test 4, and focuses on the surface of mask layer 3b.Device under test 4 plays the focussing force to measuring beam.So the focus of device under test 4 surperficial TS should be on the surface of mask layer 3b.Measuring beam arrives ccd video camera 5 through the reflection on mask layer 3b surface through imaging len 6.
Ideal ball ground roll SW part wavefront forms interference fringe through imaging len 6 arrival ccd video cameras 5 and measuring beam as the reference light beam on the receiving plane of ccd video camera 5.The output of ccd video camera 5 is admitted in the computing machine 7 and analyzes.The consistent place of radius-of-curvature of the surperficial TS of device under test 4 and ideal spherical face wavefront SW, interference fringe is sparse, and it is big more that radius-of-curvature differs, and striped is close more.Thereby can obtain the surface configuration TS of device under test 4 by these interference fringe patterns.
Provide three specific embodiments below again.
Embodiment 1
Its apparatus structure synoptic diagram as shown in Figure 1, light source 1 adopts semiconductor laser, wavelength X=650nm.Convergent lens 2, its numerical aperture are 0.9, operating distance 3mm.Solid soaks into lens 3a radius 0.764mm, use 514.5nm place refractive index be 1.8198 glass make, numerical aperture is 1.5.Make focal beam spot drop on 3b in the mask layer by regulating displacement control device 8.Device under test is placed on the piezoelectric ceramics pedestal, regulate the distance between device under test 4 and the solid infiltration lens 3, up on ccd video camera 5, obtaining striped clearly.Data acquisition to computing machine 7, is finished one-shot measurement.
Embodiment 2
Its apparatus structure synoptic diagram no longer elaborates here with the device that label is identical among the embodiment 1 as shown in Figure 3.Compensator (NULL element) 9 is placed between aperture 3c and the device under test 4, produce the wavefront that approaches at whole device under test 4 surperficial TS, situation when differing greatly to solve device under test 4 surperficial TS and ideal spherical face, promptly aspheric situation, whole measurement once just can be finished.Its precision depends on the quality of compensator 9.
Described compensator 9 can be Homology of Sphere optical device, spheric reflection optical device, aspheric transmitting optical device or aspheric surface reflective optical device.
Embodiment 3
Its apparatus structure no longer elaborates here with the device that label is identical among the embodiment 1 as shown in Figure 4.The light that sends from light source 1 is divided into measuring beam and reference beam by beam splitter 12.Reference beam arrives movably catoptron 10 by beam splitter 12.Can adjust optical path difference between reference beam and the measuring beam by mobile mirror 10.Reference beam passes through beam splitter 12 once more, and the mirror 13 that is reflected reflexes to convergent lens 2, is focused on solid by convergent lens 2 then and soaks into lens 3.Measuring beam runs into fixing catoptron 11 after being reflected by beam splitter 12 simultaneously.The measuring beam quilt is reflected back into beam splitter 12 again.Then reflex to catoptron 13, catoptron 13 reflexes to convergent lens 2 with measuring beam, is focused on by convergent lens 2 that solid soaks into lens 3 and reference beam forms aperture 3c together in mask layer 3b.Measuring beam shines device under test 4 surperficial TS through small holes 3c.After being reflected by device under test 4 surperficial TS, measuring beam focuses on the surface of mask layer 3b.After mask layer 3b surface reflection, arrive ccd video camera 5 through imaging len 6.Reference beam directly arrives imaging len 6 through small holes 3c, arrives ccd video camera 5 through imaging len 6.Reference beam and measuring beam form interference fringe on ccd video camera 5 receiving planes.
The advantage of present embodiment is: can adjust the optical path difference of two light beams by mobile mirror 11, and then adjust the contrast of interference fringe, improve measuring accuracy.
It is method among Fig. 3 that this embodiment can use embodiment 2 equally, promptly uses compensator 9 to solve aspheric detection problem.

Claims (6)

1. a point-diffraction interferometer that detects surface configuration comprises opticator and data acquisition, processing and control section, it is characterized in that:
Described opticator comprises laser instrument (1), along on the optical axis of laser beam working direction, be provided with convergent lens (2) successively, the solid that is coated with mask layer (3b) soaks into lens (3), place device under test (4) above optical axis, the below is provided with imaging len (6);
Described data acquisition, processing and control section comprise ccd video camera (5), computing machine (7) and displacement controller (8);
The position relation of above-mentioned each components and parts is as follows: this solid soaks into lens (3) and is fixed on this displacement control device (8), computing machine (7) connects and controls the work of ccd video camera (5) and displacement controller (8), the laser beam that laser instrument (1) sends is behind convergent lens (2), its focus drops in the middle of the mask layer (3b) of solid infiltration lens (3) one sides, form aperture and shine device under test (4) through this aperture (3c), the measuring beam of the surperficial TS reflection of this device under test (4) focuses on the surface of this mask layer (3b), after the reflection of this mask layer (3b), this measuring beam and enter ccd video camera (5) through imaging len (6) together from the reference beam that aperture (3c) sends.
2. point-diffraction interferometer according to claim 1 is characterized in that described solid soaks into lens (3a) and made by glass of high refractive index, and described mask layer (3b) is the antimony film.
3. point-diffraction interferometer according to claim 1 is characterized in that described displacement control device (8) is a high-precision motor, accepts the instruction of computing machine (7) and moves.
4. point-diffraction interferometer according to claim 1 is characterized in that also being provided with compensator (9) between described aperture (3c) and the device under test (4).
5. point-diffraction interferometer according to claim 4 is characterized in that described compensator (9) can be Homology of Sphere optical device, spheric reflection optical device, aspheric transmitting optical device or aspheric surface reflective optical device.
6. point-diffraction interferometer according to claim 1, it is characterized in that also being provided with between described laser instrument (1) and the convergent lens (2) beam splitter (12), removable catoptron (10) and stationary mirror (11), the laser beam that laser instrument (1) is launched at first is divided into measuring beam and reference beam by beam splitter (12), and this measuring beam is reflexed to catoptron (13) by beam splitter (12) after being run into the reflection of stationary mirror (11) after beam splitter (12) reflection again; And reference beam arrives removable catoptron (10) by beam splitter (12), by inciding catoptron (13) by beam splitter (12) once more after the reflection of removable catoptron (10), this catoptron (13) reflexes to convergent lens (2) with the reference beam and the measuring beam of above-mentioned incident.
CN 03115412 2003-02-14 2003-02-14 Spot diffraction interferometer for measuring surface shape Pending CN1431477A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 03115412 CN1431477A (en) 2003-02-14 2003-02-14 Spot diffraction interferometer for measuring surface shape

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 03115412 CN1431477A (en) 2003-02-14 2003-02-14 Spot diffraction interferometer for measuring surface shape

Publications (1)

Publication Number Publication Date
CN1431477A true CN1431477A (en) 2003-07-23

Family

ID=4790639

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 03115412 Pending CN1431477A (en) 2003-02-14 2003-02-14 Spot diffraction interferometer for measuring surface shape

Country Status (1)

Country Link
CN (1) CN1431477A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101799279A (en) * 2010-04-16 2010-08-11 北京理工大学 Optical fiber point diffraction phase shift interferometry method of surface shape of large relative aperture sphere
CN101709956B (en) * 2009-11-06 2011-01-05 北京理工大学 Optical fiber point diffraction phase shifting interferometry of optical plane surface shape
CN101644600B (en) * 2008-12-25 2011-11-16 长春理工大学 Embedded type laser beam quality measuring device
CN103557948A (en) * 2013-09-25 2014-02-05 南京理工大学 Optical system wavefront measurement device and method based on circular carrier frequency phase demodulation method
CN105928454A (en) * 2016-04-15 2016-09-07 中国科学院光电研究院 Double-fiber point diffraction full-view-field low-frequency heterodyne interferometer
CN106289096A (en) * 2015-12-29 2017-01-04 中国科学院长春光学精密机械与物理研究所 A kind of convex spherical mirror surface testing system and detection method
CN106338258A (en) * 2015-12-21 2017-01-18 中国科学院长春光学精密机械与物理研究所 Device and method for pinhole alignment of point diffraction interferometer
CN106415191A (en) * 2013-08-19 2017-02-15 康宁股份有限公司 Grazing-incidence interferometer with dual-side measurement capability
CN108732066A (en) * 2017-04-24 2018-11-02 河北工业大学 A kind of Contact-angle measurement system
CN108801173A (en) * 2018-04-20 2018-11-13 浙江大学 Point-diffraction interference detecting system based on Nanowire Waveguides
CN113465540A (en) * 2021-07-07 2021-10-01 西安交通大学 Phase shifting method for aperture plate for pinhole point diffraction interferometry system

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101644600B (en) * 2008-12-25 2011-11-16 长春理工大学 Embedded type laser beam quality measuring device
CN101709956B (en) * 2009-11-06 2011-01-05 北京理工大学 Optical fiber point diffraction phase shifting interferometry of optical plane surface shape
CN101799279A (en) * 2010-04-16 2010-08-11 北京理工大学 Optical fiber point diffraction phase shift interferometry method of surface shape of large relative aperture sphere
CN101799279B (en) * 2010-04-16 2013-08-28 北京理工大学 Optical fiber point diffraction phase shift interferometry method of surface shape of large relative aperture sphere
CN106415191B (en) * 2013-08-19 2021-11-05 康宁股份有限公司 Grazing incidence interferometer with bilateral measurement capability
CN106415191A (en) * 2013-08-19 2017-02-15 康宁股份有限公司 Grazing-incidence interferometer with dual-side measurement capability
CN103557948A (en) * 2013-09-25 2014-02-05 南京理工大学 Optical system wavefront measurement device and method based on circular carrier frequency phase demodulation method
CN103557948B (en) * 2013-09-25 2016-03-02 南京理工大学 Based on optical system Wavefront measuring apparatus and the method for circle carrier phase demodulation method
CN106338258A (en) * 2015-12-21 2017-01-18 中国科学院长春光学精密机械与物理研究所 Device and method for pinhole alignment of point diffraction interferometer
CN106338258B (en) * 2015-12-21 2019-06-28 中国科学院长春光学精密机械与物理研究所 A kind of device and method for the alignment of point-diffraction interferometer pin hole
CN106289096A (en) * 2015-12-29 2017-01-04 中国科学院长春光学精密机械与物理研究所 A kind of convex spherical mirror surface testing system and detection method
CN106289096B (en) * 2015-12-29 2019-08-23 中国科学院长春光学精密机械与物理研究所 A kind of convex spherical mirror surface testing system and detection method
CN105928454A (en) * 2016-04-15 2016-09-07 中国科学院光电研究院 Double-fiber point diffraction full-view-field low-frequency heterodyne interferometer
CN108732066A (en) * 2017-04-24 2018-11-02 河北工业大学 A kind of Contact-angle measurement system
CN108801173A (en) * 2018-04-20 2018-11-13 浙江大学 Point-diffraction interference detecting system based on Nanowire Waveguides
CN113465540A (en) * 2021-07-07 2021-10-01 西安交通大学 Phase shifting method for aperture plate for pinhole point diffraction interferometry system
CN113465540B (en) * 2021-07-07 2022-10-25 西安交通大学 Phase shifting method for aperture plate for pinhole point diffraction interferometry system

Similar Documents

Publication Publication Date Title
US5933236A (en) Phase shifting interferometer
CN102147240B (en) Method and device for measuring multiple element parameters in differential con-focus interference manner
US20080130013A1 (en) Device and method for measurement of surfaces
CN112577446B (en) In-place surface shape splicing measuring device and method for large-caliber planar optical element
CN108152299A (en) The beauty defects detection device and detection method of high-precision optical element
CN112556990A (en) Lens refractive index measuring device and measuring method thereof
CN1431477A (en) Spot diffraction interferometer for measuring surface shape
CN112556991A (en) Lens refractive index measuring device and measuring method thereof
US5309214A (en) Method for measuring distributed dispersion of gradient-index optical elements and optical system to be used for carrying out the method
CN113092077A (en) Lens refractive index measuring device and measuring method thereof
CN115561220A (en) Light scattering angle resolution detection analysis system
CN1385675A (en) Wavefront sensor
CN113804651B (en) Lens refractive index measuring device and method based on multi-wavelength astigmatic probe
CN2599524Y (en) Dot diffraction interferometer for detecting surface shape
CN109580182B (en) Method and device for measuring refractive index of curved optical element based on Brewster's law
CN1763504A (en) Transmissive multi-beam confocal interference microscope with tens nanometer transverse resolution
CN210863101U (en) Lens refractive index measuring device
CN109458939A (en) With the lens center thickness measurement method combined of quickly feeling relieved
CN108827595A (en) Detection device based on adaptation theory optical system mismachining tolerance
CN111176075B (en) Polarization aberration detection device, objective lens test bench and photoetching equipment
CN110514411B (en) Lens refractive index detection device and method
RU183150U1 (en) AUTOCOLLIMATION INTERFEROMETRIC DEVICE FOR CENTERING OF OPTICAL ELEMENTS
CN208872262U (en) Hundred microns of range transmission-type interference testing devices
JPH11314184A (en) Optical device machining apparatus
CN216013144U (en) Nonlinear optical parameter measuring device based on 4f phase coherent imaging system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication