System and method for generating two-dimensional light or laser beam, line or pattern

Abstract

A system and method for generating a two-dimensional light or laser beam, line or pattern includes a diffractive optical element (DOE) for changing or modifying an intensity distribution of an input beam or laser beam through the DOE. A focusing lens receives the altered or modified light beam or laser beam exiting the DOE and focuses the altered or modified light beam or laser beam. The bifocal relay optics receive the focused beam or laser beam exiting the focusing lens and magnify, change, or adjust at least one length or dimension or shape of the focused beam or laser beam. Finally, imaging optics receive, converge, and output the amplified, altered, or adjusted focused beam or laser beam exiting the bifocal relay optics as an output beam or laser beam.

Description

Technical Field

[0001] The present disclosure describes a system and method for creating an adjustable laser line or pattern, wherein one or more of the length or dimension or shape of the laser line or pattern can be changed or adjusted. Background Art

[0002] There are many applications that require an adjustable laser line with a Gaussian or uniform intensity profile for illumination or imaging systems. Often, there is a requirement for a length-to-width ratio, or a different requirement for the length of the laser beam along the long axis of the laser beam and the width along the short axis of the laser beam. To achieve this requirement, it is necessary for the optical system to include a laser line generator and relay optics to provide the required size, distribution, and other properties in the illumination or imaging plane.

[0003] To date, cylindrical lenses have been used to focus (or converge) or spread (or diverge) a Gaussian laser beam in one direction while keeping one or more other directions unchanged. This approach can provide a laser line with a two-dimensional Gaussian profile for a Gaussian input beam.

[0004] To achieve a uniform intensity distribution (flat top), a cylindrical lens redistributes the input Gaussian beam into a uniform intensity profile along one dimension. Due to the difficulty of the cylindrical lens manufacturing process, it is challenging to precisely control the fan angle and profile of the output beam.

[0005] Another challenge with using cylindrical lenses is the aspect ratio of the laser line. It is difficult to achieve a high aspect ratio using cylindrical lenses. Summary of the invention

[0006] An optical system and method for changing or adjusting the intensity distribution of an optical beam or laser beam is disclosed herein, comprising a diffractive optical element (DOE) operable or configured to produce a laser line having a desired uniform intensity profile in one dimension (e.g., a major axis) and a Gaussian distribution in another dimension (e.g., a minor axis), wherein different requirements are placed on the length of the laser line along the length L on the major axis and the width W on the minor axis. To help meet these requirements, a relay optical device is also disclosed herein, operable or configured to split a propagating beam in the major and minor axes and adjust the focal lengths of the major and minor axes to produce combined individual magnifications in the major and minor axes.

[0007] Also disclosed herein is an optical system for changing or adjusting the intensity distribution of a light beam or laser beam. The optical system includes a diffractive optical element (DOE) that is operable or configured to change or modify the intensity distribution of an input light beam or laser beam that passes through and leaves the DOE. The changed or modified light beam or laser beam that leaves the DOE may be referred to in the art as a designed propagation laser beam. For consistency in this disclosure, the phrase "changed or modified light beam or laser beam" will be used hereinafter. The focusing lens is positioned to receive the changed or modified light beam or laser beam that leaves the DOE, and is operable or configured to focus the changed or modified light beam or laser beam. The bifocal relay optics is positioned to receive the focused light beam or laser beam that leaves the focusing lens, and is operable or configured to positively or negatively amplify, change or adjust at least one length or dimension or shape of the focused light beam or laser beam. The imaging optics is positioned to receive, converge and output the amplified, changed or adjusted focused light beam or laser beam that leaves the bifocal relay optics as an output light beam or laser beam.

[0008] The present invention also discloses a method for changing or adjusting the intensity distribution of a light beam or a laser beam, comprising: a) expanding and collimating an input light beam or a laser beam via a first optical unit or element; b) changing or modifying the intensity distribution of the expanded and collimated input light beam or laser beam of step a via a second optical unit or element; c) focusing the light beam or laser beam with changed or modified intensity distribution of step b via a third optical unit or element; d) positively or negatively amplifying, changing or adjusting at least one length, dimension or shape of the focused light beam or laser beam of step c via a fourth optical unit or element; and e) converging the amplified, changed or adjusted light beam or laser beam of step d into an output light beam or laser beam via a fifth optical unit or element. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an example optical system according to the principles of the present disclosure;

[0010] Figure 2 is a schematic diagram of another example optical system according to the principles of the present disclosure;

[0011] Figure 3 is a schematic perspective view of a non-limiting embodiment or example diffractive optical element (DOE) in accordance with the principles of the present disclosure;

[0012] Figure 4 It is along Figure 3 A section taken along line IV-IV in FIG. 1 ; and

[0013] Figure 5 is a flow chart of a method according to the principles of the present disclosure. DETAILED DESCRIPTION

[0014] Various non-limiting examples will now be described with reference to the drawings, wherein like reference numerals correspond to similar or functionally equivalent elements.

[0015] For the purposes of the following description, terms such as "end", "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal" and their derivatives shall relate to the example(s) oriented in the accompanying drawings. However, it should be understood that the example(s) may assume various alternative variations and step orders unless otherwise expressly specified. It should also be understood that the specific example(s) shown in the accompanying drawings and described in the following specification are merely illustrative examples or aspects of the present disclosure. Therefore, the specific examples or aspects disclosed herein should not be construed as limiting.

[0016] In addition, as used herein, all numbers used in the specification and claims to represent dimensions, physical characteristics, processing parameters, the amount of ingredients, reaction conditions, etc. should be understood to be modified by the term "approximately" or "approximately" in all cases. Thus, unless otherwise specified, the numerical values ​​given in the following specification and claims can vary according to the desired characteristics that the present disclosure attempts to obtain. At least, each numerical value should at least be interpreted according to the reported significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein should be understood to cover the starting and ending range values ​​and any and all sub-ranges contained therein. For example, the specified range of "1 to 10" should be deemed to include any and all sub-ranges between (including the minimum value 1 and the maximum value 10) a minimum value of 1 and a maximum value of 10; that is, all sub-ranges starting with a minimum value of 1 or more and ending with a maximum value of 10 or less, such as 1 to 3.3, 4.7 to 7.5, 5.5 to 10, etc. "One" or "one" refers to one or more.

[0017] As used herein, "coupled", "coupling" and similar terms refer to two or more elements being coupled, linked, fastened, connected, communicated or otherwise associated (e.g., mechanically, electrically, fluidically, optically, electromagnetically) with each other. In various examples, the elements may be associated directly or indirectly. As an example, element A may be directly associated with element B. As another example, element A may be indirectly associated with element B, e.g., via another element C. It will be understood that not all associations between various disclosed elements must be represented. Thus, couplings other than those depicted in the figures may also be present.

[0018] As used herein, when used with a list of items, the phrase "at least one of" or "at least one of..." means that different combinations of one or more of the listed items may be used and only one of the individual items in the list may be required. For example, "at least one of item A, item B, and item C" may include, but is not limited to, item A or item A and item B. This example may also include item A, item B, and item C, or item B and item C. In other examples, "at least one of..." may be, for example, but not limited to, two items A, one item B, and ten items C; four items B and seven items C; and other suitable combinations.

[0019] refer to Figure 1 In some non-limiting embodiments or examples, an example optical system according to the principles of the present disclosure may include ( Figure 1 1 and 2) an expansion and collimation optical device 2, which may include an expansion lens 4 and a collimator 6, for expanding and collimating an input light beam or laser beam 8 and outputting it to a diffractive optical element (DOE) 10. The DOE 10, described in more detail below, can modulate the amplitude and / or phase of the light beam or laser beam output by the expansion and collimation optical device 2, and then output an amplitude and / or phase modulated light beam or laser beam (or a target light pattern) 11 to a focusing lens 12.

[0020] In an example, the focusing lens 12 can focus the amplitude and / or phase modulated light beam or laser beam 11 received from the DOE 10 to a focal plane 14 of the focusing lens 12, which is located at a distance f from the focusing lens 12. In an example, the focal plane 14 can also be located at a distance f1 from a first lens L1 of a bifocal relay optics 16, which can include a second lens L2 and a third lens L3. In this example, the focal plane of lens L1 can also be the focal plane 14.

[0021] In an example, lens L1 may be a spherical lens and lenses L2 and L3 may be cylindrical lenses. However, this should not be construed in a limiting sense, as it is contemplated that bifocal relay optics 16 may include any number and / or type of lenses that facilitate operation of bifocal relay optics 16 in the manner described herein.

[0022] In an example, cylindrical lens L2 may include at least one convex surface configured such that cylindrical lens L2 has a negative focus. Cylindrical lens L3 may include at least one concave surface configured such that cylindrical lens L3 has a positive focus. Imaging optics 18 having a focal length fi may be positioned to receive a light beam or laser beam output by bifocal relay optics 16.

[0023] In an example, the imaging optical device 18 may be operable or configured to receive, converge, and output the light beam or laser beam leaving the bi-focal relay optical device 16 as an output light beam or laser beam 22. In an example, the imaging optical device 18 may include one or more lenses L4 and / or L5 and an optional filter or collimator 20, which is operable or configured to receive, converge, and output the light beam or laser beam leaving the bi-focal relay optical device 16 to a downstream system as an output light beam or laser beam 22. However, this should not be interpreted in a limiting sense, as it is contemplated that the imaging optical device 18 may include any type or number of elements deemed appropriate and / or desired by a person skilled in the art to achieve receiving, converging, and outputting the light beam or laser beam leaving the bi-focal relay optical device 16 as an output light beam or laser beam 22.

[0024] For discussion purposes only, assume that an imaginary plane P (shown by a dashed imaginary plane P) is parallel to Figure 1 (and Figure 2 ), and an imaginary plane S (shown by a dotted line representing the edge of the imaginary plane S) is perpendicular to Figure 1 (and Figure 2 ) surface. In the P plane, the combination of lenses L1, L2, and L3 comprising bifocal relay optics 16 may have a focal length that is a distance fp from focal plane 14 in an example, while in the S plane, lens L1 may be positioned a distance f1 from focal plane 14 in an example.

[0025] According to the principles of the present disclosure, the lenses L1, L2, and L3 comprising the bifocal relay optics 16 may have a fixed focal length in the S plane. However, when the position (left or right) of lens L2 is adjusted relative to the fixed lenses L1 and L3 of the bifocal relay optics 16, the lenses L1, L2, and L3 comprising the bifocal relay optics 16 may have a variable or changing focal length in the P plane.

[0026] In an example, if the focal length of the imaging optics 18 is fi, the magnification of the combination of the bifocal relay optics 16 and the imaging optics 18 in the P plane and the S plane may be defined as Mp and Ms, respectively, by the following equations:

[0027] and

[0028] In the example, and as Figure 1As shown in , at the focal plane of the focusing lens 12, the amplitude and / or phase modulated light beam or laser beam 11 leaving the DOE 10 may have a short axis a (shown by a dashed arrow) parallel to the P plane and may have a long axis b (shown by a solid arrow) parallel to the S plane. When the amplitude and / or phase modulated light beam or laser beam 11 leaving the DOE 10 passes, propagates, or traverses the dual-focus relay optics 16, the lenses L1-L3 may apply different positive and negative magnifications Mp and Ms to each of the short axis a (shown by a dashed arrow) and the long axis b (shown by a solid arrow).

[0029] In an example, the imaging optics 18 can receive, converge, and output the light beam or laser beam exiting the bifocal relay optics 16 as an output light beam or laser beam 22 having a width W and a length L. In an example, the imaging optics 18 can receive, converge, and output the light beam or laser beam exiting the bifocal relay optics 16 without enlarging the minor axis a and / or the major axis b or further adjusting the ratio of a / b as the light beam or laser beam passes, propagates, or traverses the imaging optics 18, whereby the width W and length L of the output light beam or laser beam 22 are related to the size of the minor axis a and the major axis b of the light beam or laser beam exiting the bifocal relay optics 16 and entering the imaging optics 18.

[0030] In an example, some applications may require that the P plane be used only (ie, only along the minor axis a, such as via Figure 1 ) adjusts the magnification of the amplitude and / or phase modulated light beam or laser beam 11 output by the DOE 10. However, this should not be interpreted in a limiting sense, as it is contemplated that there may also be applications that may require amplification of the amplitude and / or phase modulated light beam or laser beam 11 output by the DOE 10 only in the S plane (i.e., along the major axis b) or in both the P plane and the S plane (i.e., along the minor axis a and the major axis b), and therefore the ratio a / b. However, due to manufacturing limitations of the lenses L1-L3 of the bifocal relay optics 16, the use of Figure 1 It may be challenging to achieve a desired a / b ratio at the imaging plane of imaging optics 18 with the example optical system shown in FIG. Therefore, in examples, relay optics 24 (described next) may be required.

[0031] refer to Figure 2 An example optical system according to the principles of the present disclosure that overcomes this limitation may be similar to Figure 1 , a relay optic 24 is added between the focusing lens 12 and the bifocal relay optic 16, disposed or positioned in the path of the light beam or laser beam 11 output by the DOE 10.

[0032] In an example, the relay optics 24 may include a single lens L6, which may be a single spherical lens positioned between the focusing lens 12 and the bifocal relay optics 16. However, this should not be interpreted in a limiting sense, as it is contemplated that the relay optics 24 may include any number of lenses that enable the relay optics 24 to perform optically in the manner described below. For purposes of this description, it will be assumed that the relay optics 24 includes a single lens L6. However, this should not be interpreted in a limiting sense.

[0033] In an example, the relay optics 24 may provide an adjustable magnification calculated by

[0034]

[0035] Wherein l' is the adjustable distance between the surface of lens L6 facing the bifocal relay optical device 16 and the focal plane 26, which in this example can be the object plane of lens L1, and where l is the adjustable distance between the surface of lens L6 facing the focal plane 14 of the focusing lens 12 and the focal plane 14.

[0036] In this example, the width a and length b of the amplitude and / or phase modulated light beam or laser beam 11 leaving the DOE 10 and passing through the focusing lens 12 may be

[0037] M1×a and M1×b

[0038] where M1 is the magnification of the relay optics 24 .

[0039] In this example, a and b are the width and length of the amplitude and / or phase modulated light beam or laser beam 11 in the minor and major axes, respectively. The magnification of the relay optics 24 can be changed by adjusting the distance l, and its conjugate distance l' will change accordingly. According to the principles of the present disclosure, the length L and width W of the light beam or laser beam leaving the bifocal relay optics 16 at the image plane of the imaging optics 18 can be calculated as follows:

[0040]

[0041]

[0042] The aspect ratio (L / W):

[0043]

[0044] in:

[0045] a and b are the respective width and length of the amplitude and / or phase modulated light beam or laser beam 11 at the focal plane 14 of the DOE 10;

[0046] M1 is the magnification of the relay optics 24;

[0047] Mp and Ms are the magnifications of the bifocal relay optics in the P and S planes, respectively; and

[0048] fi is the focal length of the imaging optics.

[0049] According to the above equations, the length L and width W of the laser line output by the bifocal relay optics 16 on the image plane of the imaging optics 18 can be determined by the design parameters of the DOE 10, the relay optics 24, and the imaging optics 18, and thus can be adjusted to the nominal design values. In this example, the length-to-width ratio (L / W) can be determined by the DOE 10 and the bifocal relay optics 16, and thus the ratio of L / W can be high due to the DOE characteristics.

[0050] refer to Figure 3 and Figure 4 And continue to refer to Figure 1 and Figure 2 In an example according to the principles of the present disclosure, the DOE 10 may be a phase element that changes the intensity distribution of light passing through the DOE 10. The different intensities in the distribution of light passing through the DOE 10 are generated by different step depths (or heights) of a relief structure formed or disposed on at least a first or top surface 30 of the DOE 10. The DOE 10 may use micro-optical technology to form a specific relief structure on at least a first surface 30 of an optical material substrate 32, the specific relief structure having different depths (or heights), including a depth or height of zero (0). These relief structures with different step depths (or heights) may be formed on the optical material substrate 32 by optical glue or by an etching process.

[0051] In an example, the DOE 10 may include a plurality of relief structures 34 on a first surface 30 of the DOE 10. In an example, the relief structures 34 of the DOE 10 may be annular and may be disposed coaxially about or around an axis or point 36 of the DOE 10. However, this should not be construed in a limiting sense, as it is contemplated that the relief structures 34 may have other shapes (other than annular) and may be disposed on the surface 30 of the DOE 10 in other arrangements (other than coaxially about or around an axis or point 36). In an example, the DOE 10 may be circular (e.g., as Figure 3 ). However, this should not be construed in a limiting sense, as it is contemplated that DOE 10 may have any suitable and / or desired shape (other than circular).

[0052] In an example, the number of steps of DOE 10 may be N=2. m, where m can be an integer ≥ 2. Taking m = 2 as an example, there are four step depths representing the phase θ of 0, π / 2, π, and 3π / 2. The corresponding relationship between the phase θ of the light leaving each relief structure 34 and the step depth (or height) h of each relief structure 34 is θ = 2nπ×h / λ; where n is the refractive index of the material forming the relief structure 34, h is the total depth (or height) of the relief structure 34 from the first surface 30 of the optical material substrate 32, and λ represents the wavelength of the incident light 40.

[0053] In the example, Figure 3 and Figure 4 The DOE 10 shown in FIG. 1 includes a first surface 30 of the DOE 10 and each having a depth (or height) corresponding to the wavelength of the incident light ( Figure 4 1. The annular relief structures 34-1-34-9 having a depth (or height) h=0 relative to the top surface 30 of the DOE 10 (from left to right) may not introduce a phase shift or an additional phase shift to those portions of the incident light 40 that enter the second surface 42 of the DOE 10, pass through the optical material substrate 32, and exit the DOE 10 via the relief structures 34-1, 34-4, and 34-9 having a depth (or height) h=0 on the first surface 30 of the DOE 10.

[0054] In an example, it is contemplated that the optical material substrate 32 may be formed of a material that may introduce a phase shift to the incident light 40 passing through the optical material substrate 32 or a material that may not introduce a phase shift to the incident light 40 passing through the optical material substrate 32. For example, in the case where the optical material substrate 32 is formed of a material that introduces a phase shift, the phase shift may be introduced to all incident light 40 passing through the optical material substrate 32 from the second surface 42 to the first surface 30. In another example, in the case where the optical material substrate 32 is formed of a material that does not introduce a phase shift, the incident light 40 may pass through the optical material substrate 32 from the second surface 42 to the first surface 30 without introducing any phase shift.

[0055] In another example, the relief structures 34-2 and 34-6 having a total depth (or height) h of π relative to the top surface 30 of the DOE 10 will introduce a phase shift of π (or 180°) to those portions of the incident light 40 that enter the second surface 42 of the DOE 10, pass through the optical material substrate 32, and exit the DOE 10 via the tops of the relief structures 34-2 and 34-6. In other words, the total depth (or height) h of the relief structures 34-2 and 34-6 is selected to introduce a phase shift of π (or 180°) to those portions of the incident light 40 that exit the first surface 30 of the DOE 10 and pass through the relief structures 34-2 and 34-6.

[0056] In an example, the phase shift and overall depth (or height) h associated with the relief structure 34 described herein are relative to the wavelength λ of the incident light 40 .

[0057] In another example, the relief structures 34-3 and 34-7 having a total depth (or height) h of π / 2 relative to the top surface 30 of the DOE 10 will introduce a phase shift of π / 2 (or 90°) to those portions of the incident light 40 that enter the second surface 42 of the DOE 10, pass through the optical material substrate 32, and exit the DOE 10 via the tops of the relief structures 34-3 and 34-7. In other words, the total depth (or height) h of the relief structures 34-3 and 34-7 is selected to introduce a phase shift of π / 2 (or 90°) to those portions of the incident light 40 that exit the first surface 30 of the DOE 10 and pass through the relief structures 34-3 and 34-7.

[0058] In another example, the relief structures 34-5 and 34-8 having a total depth (or height) h of 3π / 2 relative to the top surface 30 of the DOE 10 will introduce a phase shift of 3π / 2 (or 270°) to those portions of the incident light 40 that enter the second surface 42 of the DOE 10, pass through the optical material substrate 32, and exit the DOE 10 via the tops of the relief structures 34-5 and 34-8. In other words, the total depth (or height) h of the relief structures 34-5 and 34-8 is selected to introduce a phase shift of 3π / 2 (or 270°) to those portions of the incident light 40 that exit the first surface 30 of the DOE 10 and pass through the relief structures 34-5 and 34-8.

[0059] In an example, one, some, or all of the relief structures 34-2, 34-3, 34-5, 34-6, 34-7, and 34-8 may be configured to pass or substantially pass all portions of incident light 40 that enters the relief structure 34 via the first surface 30 of the optical material substrate 32 and exits the top surface of the relief structure 34. In another example, one, some, or all of these relief structures 34 may be configured to attenuate, substantially attenuate, or block all portions of incident light 40 that enters the relief structure 34 via the first surface 30 of the optical material substrate 32 and exits the top surface of the relief structure 34 by selecting the opacity or transparency of the relief structure 34. By selecting the opacity or transparency of each relief structure 34, the amplitude of the light exiting the relief structure 34 and the phase of the light may be controlled to achieve the desired lengths of the minor axis a and the major axis b of the light beam or laser beam at the imaging plane of the bifocal relay optics 16, and thus the ratio of a / b at the imaging plane of the imaging optics 18.

[0060] Through the relief structure 34, the amplitude or phase of the incident light 40 can be modulated to achieve various optical functions, such as beam shaping or beam splitting. These relief structures 34 with different depths (or heights) h can be formed by depositing optical glue on the first surface 30 of the optical material substrate 32 or by etching the optical material substrate 32. According to the desired pattern of the amplitude and / or phase modulated light beam or laser beam 11 output from the DOE 10 to the focal plane of the focusing lens 12, the relief structure 34 may include two m The depth (or height) h of each relief structure 34 is arranged in steps, wherein the depth (or height) h of each relief structure 34 is the distance from the first surface 30 to the top of the relief structure 34 .

[0061] By adjusting the incident light 40 via the relief structure 34 m By adjusting the amplitude and / or phase of each component, the incident light 40 can be shaped into an amplitude- and / or phase-modulated output light beam or laser beam 22 having a desired intensity and phase distribution.

[0062] For example, in order to form an amplitude and / or phase modulated output light beam or laser beam 22 having a Gaussian profile distribution in one dimension (e.g., short axis a) and a uniform (flat-top) distribution along another dimension (e.g., long axis b) on the focal plane of the focusing lens 12, the full width at half maximum (FWHM) on the short axis a and the length along the long axis b of the amplitude and / or phase modulated light beam or laser beam 11 can be designed by selecting the input Gaussian beam aperture, the focal length of the focusing lens 12, and the specific relief structure 34 of the DOE. By optimizing these parameters, an amplitude and / or phase modulated light beam or laser beam 11 having a desired length in both the short axis a and the long axis b and having satisfactory uniformity can be achieved on the focal plane of the focusing lens 12.

[0063] Figure 1 and Figure 2 The embodiment includes a relief structure 34 ( Figure 3 and Figure 4 ) and the DOE 10 facing the first surface 30 of the expansion and collimation optical device 2. However, this should not be interpreted in a limiting sense, as it is contemplated that the DOE 10 including the relief structure 34 ( Figure 3 and Figure 4 The first surface 30 of the optical element 10 (shown in FIG. 1 ) may face the expanding and collimating optics 2 , while the second surface 42 may face the focusing lens 12 .

[0064] Moreover, the DOE 10 including the relief structure 34 only on the first surface 30 should not be interpreted in a limiting sense, as it is contemplated that, in examples, the relief structure 34 may be disposed on both the first surface 30 and the second surface 42. In this latter example, the total depth (or height) h of the optically aligned relief structure 34 on both surfaces may be selected to achieve a desired amplitude and / or phase of light exiting the optically aligned relief structure 34. To this end, the depth (or height) h of the relief structure 34 on both surfaces may be selected to achieve a desired intensity distribution of the output light beam or laser beam 22.

[0065] refer to Figure 5 With continued reference to all previous figures, a method according to the principles of the present disclosure begins by proceeding from a "start" step to step S1, which includes expanding and collimating an input light beam or laser beam. In an example, step S1 is performed or executed by a first optical unit or element (such as, for example, an expansion and collimation optical device 2).

[0066] The method then proceeds to step S2 which comprises changing or modifying the intensity distribution of the expanded and collimated input light beam or laser beam of step S1. In an example, step S2 is performed or executed by a second optical unit or element such as, for example, DOE 10.

[0067] The method then proceeds to step S3 which comprises focusing the light beam or laser beam of the changed or modified intensity distribution of step S2. In an example, step S3 is performed or executed by a third optical unit or element such as, for example, a focusing lens 12.

[0068] The method then proceeds to step S4, which includes positively or negatively amplifying, changing or adjusting at least one length or dimension or shape of the focused light beam or laser beam of step S3. In an example, step S4 is completed or performed by a fourth optical unit or element (such as, for example, a bifocal relay optical device 16).

[0069] The method then proceeds to step S5, which comprises converging the amplified, altered or conditioned light beam or laser beam of step S4 into an output light beam or laser beam. In an example, step S5 is performed or executed by a fifth optical unit or element, such as, for example, imaging optics 18.

[0070] The method may then proceed to the "Stop" step.

[0071] The above method may optionally include step S6 (shown in dashed lines), which includes adjusting the magnification of the focused light beam or laser beam leaving the third optical unit or element in step S3 before entering the fourth optical unit or element in step S4. In an example, this optional step may be completed or performed by a sixth optical unit or element (such as, for example, relay optical device 24).

[0072] Although the present disclosure has been described in detail based on what is currently considered to be the most practical and preferred embodiments for the purpose of illustration, it should be understood that such details are only for this purpose, and the present disclosure is not limited to the disclosed embodiments, but is intended to cover modifications and equivalent arrangements within the spirit and scope of the appended claims. For example, it should be understood that the present disclosure contemplates that one or more features of any embodiment can be combined with one or more features of any other embodiment to the extent possible.

Claims

1. An optical system for changing or adjusting the intensity distribution of a light beam or a laser beam, the optical system comprising: A diffractive optical element (DOE) operable or configured to change or modify the intensity distribution of an input light beam or laser beam passing through the DOE; a focusing lens positioned to receive the altered or modified light beam or laser beam exiting the DOE and operable or configured to focus the altered or modified light beam or laser beam; a bifocal relay optic positioned to receive the focused light beam or laser beam exiting the focusing lens and operable or configured to positively or negatively amplify, change or adjust at least one length or dimension or shape of the focused light beam or laser beam; and An imaging optical device is positioned to receive, converge and output the amplified, altered or conditioned focused light beam or laser beam exiting the bifocal relay optical device as an output light beam or laser beam.

2. The optical system of claim 1, wherein the DOE comprises a plurality of relief structures of different heights formed on a surface of the substrate. 3 . The optical system of claim 2 , wherein the height of at least one of the relief structures of different heights is zero or is the surface of the substrate.

4. The optical system of claim 2, wherein the plurality of relief structures of different heights comprises N different heights.

5. The optical system of claim 4, wherein the number of different heights N=2 m , where m is an integer greater than 1.

6. The optical system of claim 5, wherein adjacent or neighboring relief structures have different heights.

7. The optical system of claim 5, wherein: For m=2, N=4 and the step heights are 0, π / 2, π and 3π / 2, where step height 0 is the surface of the substrate.

8. The optical system of claim 5, wherein the phase of the portion of the light or laser beam that passes through the relief structure of the DOE is (θ)=(2nπ)(h / λ), where: n = refractive index of the relief structure, h is the total height of the relief structure from the surface of the substrate, and λ is the wavelength of the portion of the light beam or laser beam that passes through the relief structure.

9. The optical system of claim 1 further comprising relay optics positioned in the path of the focused light or laser beam between the focusing lens and the bifocal relay optics.

10. The optical system of claim 9, wherein the bifocal relay optics comprises a spherical lens, a first cylindrical lens, and a second cylindrical lens in the order in which the light beam or the laser beam passes through the bifocal relay optics.

11. The optical system of claim 10, wherein at least one of the following: The first cylindrical lens includes at least one convex surface configured to cause the first cylindrical lens to have a negative focus; and The second cylindrical lens includes at least one concave surface configured to allow the second cylindrical lens to have a positive focus.

12. The optical system of claim 1, further comprising expansion and collimation optics for expanding and collimating the input light beam or laser beam before entering the DOE.

13. The optical system of claim 1, wherein the input light beam or laser beam has a different intensity distribution than the output light beam or laser beam.

14. The optical system of claim 1, wherein the output optical or laser beam has an intensity distribution in the shape of an optical or laser line of length L and width W, wherein the width W is smaller than the length L.

15. A method for changing or adjusting the intensity distribution of a light beam or a laser beam, comprising: a) expanding and collimating an input light beam or laser beam via a first optical unit or element; b) changing or modifying the intensity distribution of the expanded and collimated input light beam or laser beam via a second optical unit or element; c) focusing the light beam or laser beam with changed or modified intensity distribution via a third optical unit or element; d) positively or negatively amplifying, changing or adjusting at least one length or dimension or shape of the focused light beam or laser beam via a fourth optical unit or element; and e) Converging the amplified, changed or conditioned light beam or laser beam into an output light beam or laser beam via a fifth optical unit or element.

16. The method of claim 15, wherein at least one of the following: The first optical unit or element includes expansion and collimation optics; The second optical unit or element comprises a diffractive optical element DOE; The third optical unit or element includes a focusing lens; a fourth optical unit or element comprising bifocal relay optics; and The fifth optical unit or element comprises the imaging optics.

17. The method of claim 15, wherein the output light beam or laser beam has the shape of a line of length L and width W, wherein the width W is smaller than the length L.

18. The method of claim 15, further comprising adjusting a distance between at least two lenses of a fourth optical unit or element to change the amount by which the focused light beam or laser beam of step c is positively or negatively amplified, changed or adjusted.

19. The method of claim 15, wherein the second optical unit or element comprises a plurality of relief structures of different heights formed on a surface of the substrate.

20. The method of claim 19, wherein: The plurality of relief structures of different heights include N different heights; and The number of different heights N = 2 m , where m is an integer greater than 1.

21. The method of claim 15, further comprising adjusting, via a sixth optical unit or element, a magnification of the focused light beam or laser beam exiting a third optical unit or element before entering a fourth optical unit or element.

22. The method of claim 21, wherein the sixth optical unit or element comprises relay optics.

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