WO2002016969A2 - Intravolume diffractive optical elements - Google Patents
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- WO2002016969A2 WO2002016969A2 PCT/IL2001/000789 IL0100789W WO0216969A2 WO 2002016969 A2 WO2002016969 A2 WO 2002016969A2 IL 0100789 W IL0100789 W IL 0100789W WO 0216969 A2 WO0216969 A2 WO 0216969A2
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- G—PHYSICS
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- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
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Definitions
- the present invention relates to the field of intravolume diffractive optical elements, especially those produced in transparent materials by means of digital laser engraving at very high energy densities.
- DOE's Diffractive optical elements
- Digital DOE's have been described by B.R.Brown and A. .Lohmann in the article "Complex Spatial Filtering with Binary Masks", published in Applied Optics, Vol. 5, p. 967ff, (1966).
- Such digital DOE's have generally been produced by means of mechanical micro-engraving, electron beam, ion beam or chemical etching, electron lithography or photolithography, or by other suitable techniques.
- R(r) jS(u)T(n)exp(ikd(r, ⁇ ))/d(r, ⁇ )ds (1)
- Equation (1) is the Kirchhoff approximation for the solution of the scalar Dirichlet problem with infinite boundary conditions, and with Sommerfeld radiation conditions. Equation (1) can alternatively be interpreted as the Fresnel transformation of the field S(u)r(u) from the surface of the DOE to the point r .
- the inverse problem has to be solved, whereby the incident field S(u) and the transmitted field R(u) are known and the appropriate complex transmission function of the DOE - I ⁇ u) , has to be calculated.
- Such a DOE then produces the desired transformation of the incident field such that the correct field is formed in the image plane.
- the method of representing the DOE by means of a function T( ⁇ ) is performed by assigning complex values of the transmission function to discrete pixels of the DOE. The number of pixels chosen depends on the size of the DOE and its resolution.
- the values of the transmission function for each pixel can be calculated by means of scalar diffraction theory, and form a Fourier transform of the model field. Evaluation of this Fourier series requires some approximations.
- DOE's are principally two dimensional in nature and are located on the surface of the DOE.
- Such DOE's have found limited use because of the complexity of constructing integrated multi-element devices from an assembly of 2-dimensional devices. The need to maintain correct alignment of a number of separate elements, also reduces the reliability of such a device.
- a further serious limitation is the inability to produce a coherent arrangement of independent sequential devices and a 3-dimensional spatial diffractive structure.
- Fusek describes the production of high performance optical spatial filters
- U.S. Patent No. 4,846,552, to W.B.Veldkamp et al describes a method of fabricating high efficiency binary planar optical elements based on photolithographic techniques
- U.S. Patent No. 5,428,479, to R.A. Lee describes a method of manufacture of a diffraction grating with assembled point gratings
- Modavis describes a method of forming a grating in an optical waveguide utilizing photosensitive materials. All of the above-cited prior art methods have one or more of the disadvantages mentioned in the previous paragraph.
- the present invention seeks to provide a new method of producing 3-dimensional intravolume DOE's, including both polychromatic and achromatic DOE's, in transparent materials, by creating inside the material a set of scattering centers. The position of every point of this set of scattering centers is computed, so that the set of secondary waves of light scattered from these points is such as to create the desired field by means of a suitable transformation of the incident electromagnetic field.
- the methods described in the above-mentioned references can be applied only to two dimensional structures or to an incoherent set of two-dimensional devices.
- R(r) ⁇ S(u,.) 1 .(r)exp(t (r,u i ))/ ⁇ (r,u / ) (2)
- U is the position of tth center, and a ; (r.) is the complex scattering coefficient of the tth center in direction r..
- Equation 2 is the analog of equation 1 for the 3-dimensional discrete case, but it is only a zero level approximation. Equation 2 can be evaluated in an analytical form, but an analytic solution of the inverse problem of finding a, (f j ) when R( ⁇ j ) and s(u,.) are given, cannot be achieved. The inverse problem can, however, be converted to one of functional extremum searching:
- a solution of equation (3) for the value of a .(F .) can be obtained both for fixed positions of the scattering centers and for a discrete set of real scattering coefficients.
- the solution of this problem for a fixed set of scattering centers at u can be performed by means of a number of well known methods.
- One example is by the use of the modified genetic algorithm, as discussed in "Multi-element diffractive optical designs using evolutionary programming", by D.Brown and A.Kathman, published in SPIE, Vol. 2404, pp.17-27,(1995), hereby incorporated in its entirety by reference.
- a more accurate mathematical model of a three-dimensional discrete DOE can be obtained using an analog to Faddeev' s approach of T-matrix formalism for a multi-body system, as described in L. D. Faddeev and S. P. Merkuriev, "Quantum Scattering Theory for Several Particle Systems", published by Kluver, Dordrech, 1993.
- ⁇ 0 ( ⁇ ,k) is a solution of the wave equation for a specific wave vector k,k - k and ⁇ ,. is the Laplace operator in x space.
- equation (4) can be written as:
- Equation (4) and (4a) can be combined into one equation:
- the perturbed Green's function can then be represented as:
- the T matrix for (10) obeys the following i equation:
- T i (z) w(z,. ⁇ i ) ⁇ (z,.-u i )g 0 (z)T(z)
- T(z) T i (z) (12) j
- T t (z) t t (z) - t t (z)g 0 (z) ⁇ t, (z) +t t (z)g 0 (z) ⁇ t,. (z)g 0 (z) ⁇ t k (z) - j ⁇ i J ⁇ t k ⁇ j
- T(z) and t(z) are vectors with components T t (z) and t, (z) respectively.
- the total resulting scattering amplitude A(x,k,k) according to (9) can be presented as:
- equation (3) allows obtaining the correct problem definition for manifold scattering.
- equation (3) is the possibility of sequential evaluation of the extremum according to the level of approximation, or in the present case, to the degree of operator ⁇ (z) .
- equation (9) allows another interpretation of Green's function G(k 2 ) as a propagation operator for the wave function and the solution ⁇ ( ⁇ ,k) as a result of transformation of the incident field ⁇ 0 (x,k) .
- Intravolume optical breakdown involves the focusing of the beam from a laser emitting ultra-short pulses, of the order of tens of picoseconds or less, into the volume of a transparent material, by means of a high quality objective lens, such that a focal spot of size close to the diffraction limit for the laser wavelength, is obtained within the material.
- the material undergoes optical breakdown, since the power density of the focused beam far exceeds the threshold above which non-linear effects occur in the transmission properties of the otherwise transparent materials, and the material strongly absorbs the focused beam. Because of the intense power density, atomic and molecular bonds of the material are broken down, and the material decomposes almost instantaneously into its basic components, generally highly ionized component atoms, leaving behind a tiny diffuse scattering center.
- the optical breakdown damage zones constituting these scattering centers define the pixels of the DOE. The position of these scattering centers is calculated according to the function of the DOE planned, using one of the methods described hereinabove, such as by the modified genetic algorithm.
- the DOE may be produced in a transparent molecularly porous material, such as Corning Glass type Porous Vicor 7930, and the voids created at the optical breakdown damage zones filled with a liquid having a different refractive index to that of the transparent material, for instance by immersion in the liquid. The scattering then takes place from those points of different refractive index.
- the liquids used can preferably be organic solvents such as acetone, alcohol or toluene, or other suitable liquids such as oils, having suitably different refractive index from the host material.
- a sealant layer is preferably applied to the DOE so produced in order to avoid loss of the filling liquid.
- the liquid used can act as a carrier of another active material, such as a phosphorescent or a fluorescent dye, or a simple absorbent dye, and the DOE operative by scattering from this dye under the relevant conditions of activation or view.
- another active material such as a phosphorescent or a fluorescent dye, or a simple absorbent dye
- the above method is capable of producing pixels of size close to the diffraction limit for the laser light used, of the order of 0.5 ⁇ m, and at distances apart of less then 1 ⁇ m.
- DOE's are called digital DOE's.
- the scattering points essentially consist of a series of digital ones or zeros, in so far as their scattering ability is concerned, such DOE's are also known as binary DOE's.
- t .(k,k',z) t(k,k',z)ex ⁇ jt(u ,k-k') .
- the accuracy of the arrangement of pixels inside the transparent material depends on the quality of the optical and mechanical beam positioning system, and on the size of the pixels produced. In practice, with good quality focusing optics, it is possible to create pixels of size close to ⁇ /2 of the engraving light, which is the theoretical limit for such a focusing process, and with a location accuracy of greater than ⁇ /S . Pixel sizes and location accuracies of this order should thus be sufficient for the production of intravolume DOE's for use in the visible range, by means of the methods of this invention.
- the DOE's constructed according to the present invention can be used for a number of purposes in the field of optics, including, but not limited to, focusing, beam shaping, wavefront correction, beam splitting, optical filtering, diffracting, partial reflecting, and others. According to a further preferred embodiment of the invention, if the scattering points are produced throughout the volume of the transparent material in a random manner, an optical diffuser is obtained, whose density is dependent on the density of scattering centers produced.
- DOE's are monochromatic and are designed for one specific wavelength.
- DOE's constructed according to preferred embodiments of the present invention are primarily three dimensional, and this enables the selection of a wide range of spatial wave vectors for achieving polychromatic design. This means that it is possible to control the scattering of a set of electromagnetic waves with different wavelengths. This feature allows achromatic DOE's to be achieved, when the element is designed such that all the waves with different wavelength are scattered in the same way.
- DOE's can be utilized for transformation of an incident electromagnetic field in a predetermined manner. It is thus possible to compensate a beam emitted from a light source, such as, for instance, a laser diode, or a LED, for undesired properties therein.
- a light source such as, for instance, a laser diode, or a LED
- the light emitted from the source is measured, and the results analyzed and compared with the desired output of the source.
- a set of data according to the differences between the measured and desired beam characteristics is used to produce a DOE according to preferred methods of the present invention.
- this DOE is incorporated into the front envelope of the source, or elsewhere in its beam path, it compensates the emitted light to achieve the desired beam characteristic.
- correction can be achieved for undesired characteristics in spatial intensity (mode form), phase or even chromatic variations of the beam.
- spatial intensity corrections a simple beam profile is sufficient
- phase correction a full phase profile of the incident beam is necessary
- chromatic correction a wavelength profile is preferably used.
- the correcting DOE is calculated according to the differences between the undesired beam characteristics and the desired beam characteristics.
- the DOE's constructed according to the present invention are intravolume elements, using all three dimensions of the support material, they are well suited for multielement designs, since all the elements can be located in one piece of glass, and do not need any adjustment or maintenance.
- Such a multi-element device can also be constructed by locating the scattering points in a plurality of separate planes, thus constituting a sequential set of diffractive elements.
- the DOE's constructed according to the present invention can be used in hybrid optical assemblies by locating them inside the volume of classic refractive elements constituting a hybrid optical device.
- a method of producing in a solid transparent material, a diffractive optical element for the predefined transformation of an incident wave consisting of the steps of developing a mathematical model of the diffractive optical element in terms of the transformation, using the mathematical model for determining a set of points which form the diffractive optical element, and focusing at least one pulsed laser beam onto the points, such that it causes optical breakdown damage at the points.
- the mathematical model may review the discrete structure of the set of points and take into account the amplitude and phase properties of their scattering diagram.
- the determining is performed by finding a numerical solution to the equation
- the solid transparent material is a porous material
- the points of the optical breakdown damage may be filled with a liquid having a refraction index different from that of the transparent material.
- the points are located on a fixed grid, have sizes determined from a definite set and form a digital diffractive optical element.
- the sizes may be variable and are achieved by varying the number of pulses of the pulsed laser beam used to form each point.
- the diffractive optical element may be operative to compensate for undesired properties of the incident wave.
- a method as described above and also consisting of the step of impinging a monitoring incident wave onto the diffractive optical element during at least part of the step of focusing a pulsed laser beam onto each of the points sequentially, and correcting the diffractive optical element during production in accordance with the scattered wave obtained in real time.
- any of the methods described above may be used to correct an aberration in an optical element by the formation of a diffractive optical element within the element.
- a monitoring incident wave is impinged onto the optical element during at least part of the step of focusing a pulsed laser beam onto each of the points sequentially, and the diffractive optical element corrected during production in accordance with aberrations obtained from the optical element in real time.
- the diffractive optical element may be a wave front corrector, or a lens, or a grating, or a beam splitter or a filter, or has a predefined reflectance to the incident wave, or is an optical diffuser.
- the at least one laser beam may be a plurality of laser beams, operative to simultaneously produce a plurality of diffractive optical elements.
- a laser system for simultaneous production of a plurality of damage points in a solid transparent material, consisting of a pulsed laser beam capable, when focused, of causing optical breakdown damage at the points in the material, and a master diffractive optical element, through which the pulsed laser beam is passed, the master diffractive optical element being predefined such as to focus the laser beam onto the locations of the plurality of damage points.
- the laser system can further include a computer control system for relative displacement of the sample and the laser beam, and can further include a focusing optical system.
- a laser system for producing a diffractive optical element in a solid transparent material consisting of a pulsed first laser beam capable, when focused, of causing optical breakdown damage at points in the material, an optical system for focusing the first laser beam, a computer controlled motion system for moving the solid transparent material in the first laser beam, such that the optical breakdown damage is formed at the desired points, a second laser beam, projected through the solid transparent material, operative as a probing beam, and an imaging system consisting of a camera for monitoring the diffraction of the second laser beam through the diffractive optical element, the imaging system providing data to the computer controlled motion system, such that the diffractive optical element is correctly formed in real time according to the diffractive effects obtained.
- Fig. 1 is a schematic illustration of a computer controlled system for the production of computer generated intravolume 3-dimensional DOE's, constructed and operative according to a preferred embodiment of the present invention
- Fig. 2(a) is a schematic illustration of the use of a DOE, constructed and operative according to a preferred embodiment of the present invention, for beam focusing;
- Fig. 2(b) shows a typical DOE pixel arrangement for performing the focusing functions shown in Fig. 2(a);
- Fig. 2(c) is a view of the logarithm of the energy distribution of the resulting field in the focal plane;
- Fig. 3(a) is a schematic illustration of the use of a DOE, constructed and operative according to a preferred embodiment of the present invention, for beam shaping;
- Fig. 3(b) shows a typical example of a DOE pixel arrangement for performing the shaping functions shown in Fig. 3(a);
- Fig. 3(c) is a view of the energy distribution of the resulting field in the object plane;
- Fig. 4(a) is a schematic illustration of using a DOE, constructed and operative according to a preferred embodiment of the present invention, as a wave front corrector
- Fig. 4(b) is an illustration of the known energy distribution in the incident field, which may have aberrations which it is desired to remove.
- Fig. 4(c) shows the desired energy distribution
- Fig. 4(d) shows a sample of a DOE pixel arrangement
- Fig. 4(e) illustrates the energy distribution obtained in the refracted field;
- Fig. 5 is a schematic illustration of a system, according to a further preferred embodiment of the present invention, whereby replication of DOE's can be performed without the need for auxiliary focussing or scanning, by means of passing a writing laser beam through a master DOE;
- Fig. 6 is a schematic illustration of a system, according to a further preferred embodiment of the present invention, in which the DOE being engraved is dynamically inspected by means of a probe laser beam transmitted through the DOE and imaged thereby, and the laser engraving system adjusted in real time to obtain the desired DOE according to the image obtained.
- FIG. 1 illustrates schematically a computer-controlled system for the production of 3-dimensional intravolume Diffractive Optical Elements, constructed and operative according to a preferred embodiment of the present invention.
- a femtosecond pulsed laser 10 emits a beam 12 which is deflected by beam deflector 14 and focused by means of a high quality optical system 16, into a transparent sample 18 in which the DOE is to be produced.
- the laser pulse peak power is sufficiently high to achieve optical breakdown for the particular material of the sample.
- the sample is disposed on a CNC-controlled three-axis precision stage 20.
- the motions along the X-Y-Z axes are executed by means of motors 22, 24, 26.
- Selection of the position at which the spot is to be focused is performed either by motion of the sample using the CNC-controlled motion stage 20, or by means of a the fast optical beam scanner 14, which operates in the x-y plane only, or by a combination of both.
- a computer 27, supplies data to a CNC controller unit 28, which supervises all of the functions of the system, synchronizing the firing of the laser pulses with the motion of the X-Y-Z stage and deflector, such that the required arrangement of scattering points is formed throughout the volume of the sample, in accordance with a predefined program.
- the method by which the predefined program determines the location of each scattering center is described hereinabove.
- Figs. 2(a) schematically illustrates the use of a DOE 30, constructed and operative according to a preferred embodiment of the present invention, in a beam focusing application.
- the beam from the laser 33 is focused at the point 31.
- Fig. 2(b) is a typical DOE pixel arrangement for performing the focusing function shown in Fig. 2(a).
- Fig. 2(c) is a view of the logarithm of the energy distribution of the resulting field in the focal plane.
- This beam focusing element resembles a Fresnel Zone plate, but is constructed from scattering points. It differs from a Zone plate due to the phase properties of the T- matrix (i.e. scattering amplitude equation (9)A(x,k,k)).
- Fig. 3(a) is a schematic illustration of the use for beam shaping of a DOE 32, constructed and operative according to another preferred embodiment of the present invention.
- the laser 33 produces a plane coherent wavefront 34, which is directed to be incident on the DOE 32.
- the arrangement of scattering centers produced by the methods of the present invention within the volume of the DOE, are such as to cause the plane wave 34 to diverge to produce the desired high contrast image 35 in the image plane.
- Fig. 3(b) shows a typical example of a DOE pixel arrangement for performing the shaping functions shown in Fig. 3(a).
- Fig. 3(c) is a view of the energy distribution of the resulting field in the object plane.
- Such a DOE can be used in encoding, encryption or marking applications.
- Fig. 4(a) is a schematic illustration of the use of a DOE 36, constructed and operative according to a preferred embodiment of the present invention, as a wave front corrector.
- the DOE operates by preferentially spatially diffracting the incident beam 37 in such a way that the incident field E(x,y) is refracted to a value U(x,y) for every point in the transmitted beam 38.
- Fig. 4(b) is an illustration of the known energy distribution in the incident field, which may have aberrations which it is desired to remove.
- Fig. 4(c) shows the desired energy distribution.
- Fig. 4(d) shows a sample of a DOE pixel arrangement.
- Fig. 4(e) illustrates the energy distribution obtained in the refracted field after passage through the field-correcting DOE.
- Such an aberration- correcting DOE may also be produced inside another optical element, whether conventional or a DOE, in order to correct aberrations present in that optical element.
- Fig. 5 is a schematic illustration of another preferred embodiment of the present invention, wherein repeated samples of a DOE 40 are produced by means of passing a writing beam 42 produced by a laser 33, through a master DOE 43, to provide the desired image of the desired DOE in the focal plane 44.
- the master DOE 43 may be calculated and produced according to any of the previous embodiments described hereinabove, or by any other suitable method.
- the laser beam is focused so as to produce an assembly of scattering points by means of optical breakdown, such that multiply repeated samples of the desired DOE is obtained. If the laser beam is sufficiently energetic, it can produce several scattering points simultaneously for each incident laser pulse, by differently diffracted beams of the writing laser beam.
- the writing beam is diffracted by the master DOE such that it can engrave several DOE samples simultaneously, thereby increasing productivity of the system.
- Fig. 6 is a schematic illustration of yet another preferred embodiment of the present invention, whereby active feedback is used to control the properties of a DOE during production in a transparent material by means of optical breakdown.
- the DOE is dynamically inspected by means of a second probe laser beam transmitted through the DOE and imaged by it, and the laser engraving system adjusted in real time to obtain the desired DOE characteristics according to the resulting image obtained.
- the DOE production system is similar to that shown in Fig. 1, and consists of an engraving laser 50, whose beam is focused by means of an objective lens onto the sample 54 in which the DOE is to be engraved.
- the sample 54 is mounted on a motor driven CNC-controlled motion table 56.
- a probe laser 60 provides a collimated beam 62 which is used as the probe beam for testing the DOE under production 54.
- the probe laser beam is preferably directed onto the optical axis of the DOE by means of a dichroic beam combiner 64. After being focused by the DOE, the image is recorded by means of a CCD camera 66 mounted on an inspection microscope 68.
- This CCD camera provides data in real time to the control system 70, about the actual focusing performance of the DOE being produced.
- the image is compared with the known image expected from the desired DOE performance, and the control system then adjusts the engraving laser and motion system to correct the DOE characteristics to provide the desired DOE performance.
- a set of scattering centers can be produced for the purpose of amending the optical properties of a material in a predetermined manner.
- the refraction coefficient or transparency are examples of the properties of the material that can be thus amended.
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Application Number | Priority Date | Filing Date | Title |
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EP01961096A EP1320770A2 (en) | 2000-08-24 | 2001-08-23 | Intravolume diffractive optical elements |
US10/362,800 US6884961B1 (en) | 2000-08-24 | 2001-08-23 | Intravolume diffractive optical elements |
CA002420370A CA2420370A1 (en) | 2000-08-24 | 2001-08-23 | Intravolume diffractive optical elements |
AU2001282474A AU2001282474A1 (en) | 2000-08-24 | 2001-08-23 | Intravolume diffractive optical elements |
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IL138077 | 2000-08-24 | ||
IL13807700A IL138077A (en) | 2000-08-24 | 2000-08-24 | Intravolume diffractive optical elements in transparent materials |
GB0031146A GB2368663B (en) | 2000-08-24 | 2000-12-20 | Intravolume diffractive optical elements in transparent materials |
GB0031146.4 | 2000-12-20 |
Publications (2)
Publication Number | Publication Date |
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WO2002016969A2 true WO2002016969A2 (en) | 2002-02-28 |
WO2002016969A3 WO2002016969A3 (en) | 2003-04-17 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/IL2001/000789 WO2002016969A2 (en) | 2000-08-24 | 2001-08-23 | Intravolume diffractive optical elements |
Country Status (4)
Country | Link |
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EP (1) | EP1320770A2 (en) |
AU (1) | AU2001282474A1 (en) |
CA (1) | CA2420370A1 (en) |
WO (1) | WO2002016969A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1686412A2 (en) | 2004-12-03 | 2006-08-02 | Ohara Inc. | Optical component and method of manufacture of optical component |
WO2006113145A2 (en) * | 2005-04-13 | 2006-10-26 | Kla-Tencor Technologies Corporation | Systems and methods for mitigating variances on a patterned wafer using a prediction model |
US7459242B2 (en) | 2002-02-20 | 2008-12-02 | Pixer Technology Ltd. | Method and system for repairing defected photomasks |
WO2021170555A1 (en) | 2020-02-24 | 2021-09-02 | Carl Zeiss Smt Gmbh | Method and apparatus for performing an aerial image simulation of a photolithographic mask |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CH698833B1 (en) | 2007-04-03 | 2009-11-13 | Diamond Sa | Coupling piece for a plug connection. |
Family Cites Families (3)
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---|---|---|---|---|
RU2008288C1 (en) * | 1991-04-23 | 1994-02-28 | Санкт-Петербургский государственный университет | Method of laser forming images in solid media |
US6087617A (en) * | 1996-05-07 | 2000-07-11 | Troitski; Igor Nikolaevich | Computer graphics system for generating an image reproducible inside optically transparent material |
JP3433110B2 (en) * | 1998-08-03 | 2003-08-04 | 科学技術振興事業団 | Three-dimensional diffractive optical element and method of manufacturing the same |
-
2001
- 2001-08-23 WO PCT/IL2001/000789 patent/WO2002016969A2/en active Search and Examination
- 2001-08-23 AU AU2001282474A patent/AU2001282474A1/en not_active Abandoned
- 2001-08-23 EP EP01961096A patent/EP1320770A2/en not_active Withdrawn
- 2001-08-23 CA CA002420370A patent/CA2420370A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
D.BROWN; A.KATHMAN: "Multi-element diffractive optical designs using evolutionary programming", SPIE, vol. 2404, 1995, pages 17 - 27 |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7459242B2 (en) | 2002-02-20 | 2008-12-02 | Pixer Technology Ltd. | Method and system for repairing defected photomasks |
EP1686412A2 (en) | 2004-12-03 | 2006-08-02 | Ohara Inc. | Optical component and method of manufacture of optical component |
EP1686412A3 (en) * | 2004-12-03 | 2006-08-16 | Ohara Inc. | Optical component and method of manufacture of optical component |
US7405883B2 (en) | 2004-12-03 | 2008-07-29 | Ohara Inc. | Optical component and method of manufacture of optical component |
WO2006113145A2 (en) * | 2005-04-13 | 2006-10-26 | Kla-Tencor Technologies Corporation | Systems and methods for mitigating variances on a patterned wafer using a prediction model |
WO2006113145A3 (en) * | 2005-04-13 | 2007-11-15 | Kla Tencor Tech Corp | Systems and methods for mitigating variances on a patterned wafer using a prediction model |
WO2021170555A1 (en) | 2020-02-24 | 2021-09-02 | Carl Zeiss Smt Gmbh | Method and apparatus for performing an aerial image simulation of a photolithographic mask |
US11366382B2 (en) | 2020-02-24 | 2022-06-21 | Carl Zeiss Smt Gmbh | Method and apparatus for performing an aerial image simulation of a photolithographic mask |
Also Published As
Publication number | Publication date |
---|---|
EP1320770A2 (en) | 2003-06-25 |
CA2420370A1 (en) | 2002-02-28 |
WO2002016969A3 (en) | 2003-04-17 |
AU2001282474A1 (en) | 2002-03-04 |
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