Wavefront sensor systems and methods of using the same

Abstract

A wavefront sensor is disclosed for measuring a wavefront. The sensor can include a mask configured to receive incident light of the wavefront and including irregularly spaced apertures that respectively transmit sub-beams of the incident light. A lenslet array can be positioned to receive sub-beams of the incident light from the mask so that individual lenslets of the lenslet array collect and focus the sub-beams of incident light. A camera can be included and positioned in a focal plane of the mask and the lenslet array, the camera configured to obtain a digital image of the lenslet array and / or the mask related to the incident light. A system controller can measure the wavefront of the incident light based at least partially on the digital image.

Description

WAVEFRONT SENSOR SYSTEMS AND METHODS OF USING THE SAMECROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 681.571 filed August 9. 2024. entitled “WAVEFRONT SENSOR SYSTEMS AND METHODS OF USING THE SAME.” The foregoing application is hereby incorporated by reference in its entirety, including but not limited to those portions that specifically appear hereinafter, but except for any subject matter disclaimers or disavowals, and except to the extent that the incorporated material is inconsistent with the express disclosure herein, in which case the language in this disclosure shall control.FIELD

[0002] This application generally relates to wavefront sensors.BACKGROUND

[0003] Wavefront sensors are widely used across in the optics industry' for a variety of applications. For example, wavefront sensors are used for measuring and characterizing optical wavefronts, measuring optical surface figures and imperfections, and / or aligning optical systems.

[0004] Wavefront sensors, at their core, measure the slope of incident light’s wavefront. By measuring the slope of sub-regions of the beam, the beam's wavefront can be reconstructed and characterized. Depending on the magnitude of slopes, and the characteristics of the beams, there are various methods of measuring wavefront. However, common limitations of many wavefront sensors include their inability to easily and accurately measure a large range of wavefront errors, regardless of the beam’s overall tilt, diameter, wavelength, and coherence.

[0005] Accordingly, there is a need for improved wavefront sensors.SUMMARY

[0006] In some aspects, a wavefront sensor is disclosed for measuring a wavefront. The sensor can include a mask configured to receive incident light of the wavefront and including irregularly spaced apertures that respectively transmit sub-beams of the incident light. A lenslet array can be positioned to receive sub-beams of the incident light from the mask so that individual lenslets of the lenslet array collect and focus the sub-beams of incidentlight. A camera can be included and positioned in a focal plane of the mask and the lenslet array, the camera configured to obtain a digital image of the lenslet array and / or the mask related to the incident light. A system controller can measure the wavefront of the incident light based at least partially on the digital image.

[0007] In some aspects, the wavefront sensor can include a source of collimated light having the wavefront. The source of collimated light can include a laser.

[0008] In some aspects, the controller is configured to measure the wavefront based on positions of the sub-beams relative to both respective reference positions and neighboring subbeams.

[0009] In some aspects, the controller is configured to determine a null position of each sub-beam and to calculate each sub-beam’s displacement from its null position.

[0010] In some aspects, the controller is configured to measure a tilt of the incident light, and wherein the tilt is an average tilt.

[0011] In some aspects, the controller is configured to measure the wavefront without a tilt.

[0012] In some aspects, the controller is configured to measure tilt of a plurality of diffracted beams.

[0013] In some aspects, the controller is configured to measure a wavefront error of the incident light.

[0014] In some aspects, the controller is configured to measure a wavefront error of the incident light with Zemike terms removed.

[0015] In some aspects, the controller is configured to measure beam deviation as light refracts.

[0016] In some aspects, the controller is configured to measure precession radius noise.

[0017] In some aspects, the controller is configured to measure bearing wobble.

[0018] In some aspects, the sensor can include a diffuser between the lenslet array and the camera.

[0019] In some aspects, the sensor does not include a mask or a diffuser.

[0020] In some aspects, the sensor includes a field-of-view (FOV) of approximately + / - 10 degrees.

[0021] In some aspects, a wavefront sensor is disclosed for measuring a wavefront. The sensor can include a diffuser, a lenslet array including an array of microlenses that collect and focus sub-beams of incident light onto the diffuser, a camera having a focal plane of the diffuser and the lenslet array, the camera configured to obtain a digital image of the lensletarray and / or the diffuser related to the incident light, and a controller configured to measure the wavefront of the incident light based at least partially on the digital image.

[0022] In some aspects, a method is disclosed for measuring a wavefront. The method can include passing, at a lenslet array, incident light of the wavefront or sub-beams of the incident light of the wavefront; imaging, by a camera, one or more patterns of sub-beams the incident light passed through the lenslet array to create one or more digital images; and measuring, by a system controller and based on the one or more digital images, the wavefront of the incident light.

[0023] In some aspects, the method can include generating collimated light having the wavefront, wherein a source of collimated light includes a laser.

[0024] In some aspects, the method can include using a beamsplitter to reflect light from a light source to a surface the wavefront from which is to be measured, to receive light that is reflected, and to transmit such light which then is incident on the lenslet array.

[0025] In some aspects, the lenslet array receives light that is transmitted by an optical component generating the wavefront to be measured.

[0026] In some aspects, the wavefront is measured based on positions of the sub-beams on the lenslet array relative to both respective reference positions and neighboring sub-beams.

[0027] In some aspects, the step of measuring can include measuring the wavefront based on positions of sub-beams relative to both respective reference positions and neighboring sub-beams.

[0028] In some aspects, the method can include determining, by the system controller, a null position of each sub-beam and calculating each sub-beam’s displacement from its null position.

[0029] In some aspects, the method can include measuring, by the system controller, a tilt of the incident light, and wherein the tilt is an average tilt.

[0030] In some aspects, the step of measuring the wavefront includes measuring, by the system controller, the wavefront without a tilt.

[0031] In some aspects, the method can include measuring, by the system controller, a tilt of a plurality of diffracted beams.

[0032] In some aspects, the method can include measuring, by the system controller, a wavefront error of the incident light.

[0033] In some aspects, the method can include measuring, by the system controller, a wavefront error of the incident light with Zemike terms removed.

[0034] In some aspects, the method can include measuring, by the system controller, beam deviation as light refracts.

[0035] In some aspects, the method can include measuring, by the system controller, precession radius noise.

[0036] In some aspects, the method can include measuring, by the system controller, bearing wobble.

[0037] In some aspects, a computer-implemented system can include one or more memories storing instructions; a system controller; and one or more processors configured to execute the instructions to perform operations configured to measure a wavefront. The operations can include causing, by the system controller, incident light of the wavefront or subbeams of the incident light of the wavefront to pass at a lenslet array; imaging, by a camera, one or more patterns of sub-beams the incident light passed through the lenslet array to create one or more digital images; and measuring, by the system controller and based on the one or more digital images, the wavefront of the incident light.

[0038] In some aspects, the operations include causing, by the system controller, collimated light to be generated by a source, the collimated light having the wavefront.

[0039] In some aspects, the operation of measuring can includes measuring the wavefront based at least partially on positions of the sub-beams on the lenslet array relative to both respective reference positions and neighboring sub-beams.

[0040] In some aspects, the operation of measuring can includes measuring the wavefront at least partially based on positions of sub-beams relative to both respective reference positions and neighboring sub-beams.

[0041] In some aspects, the operations include determining, by the system controller, a null position of each sub-beam and calculating each sub-beam’s displacement from its null position.

[0042] In some aspects, the operations include measuring, by the system controller, a tilt of the incident light, and wherein the tilt is an average tilt.

[0043] In some aspects, the operation of measuring includes measuring the wavefront without a tilt.

[0044] In some aspects, the operation of measuring includes measuring a tilt of a plurality of diffracted beams.

[0045] In some aspects, the operation of measuring includes measuring a wavefront error of the incident light.

[0046] In some aspects, the operation of measuring includes measuring a wavefront error of the incident light with Zemike terms removed.

[0047] In some aspects, the operation of measuring includes measuring beam deviation as light refracts.

[0048] In some aspects, the operation of measuring includes measuring precession radius noise.

[0049] In some aspects, the operation of measuring includes measuring bearing wobble.

[0050] It is to be understood that any respective features / examples of each of the aspects of the disclosure as described herein may be implemented together in any appropriate combination, and that any features / examples from any one or more of these aspects may be implemented together with any of the features of the other aspect(s) as described herein in any appropriate combination to achieve the benefits as described herein.BRIEF DESCRIPTION OF DRAWINGS

[0051] The above and further aspects of this disclosure are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. The figures depict one or more implementations of the inventive devices, by way of example only, not by way of limitation.

[0052] FIG. 1 schematically illustrates components of an example configuration of the present w avefront sensor.

[0053] FIG. 2 schematically illustrates aspects of an example configuration of a wavefront sensor of this disclosure.

[0054] FIG. 3 schematically illustrates aspects of an example configuration of a wavefront sensor of this disclosure.

[0055] FIG. 4 schematically illustrates aspects of an example configuration of a wavefront sensor of this disclosure.

[0056] FIG. 5 schematically illustrates aspects of an example configuration of a wavefront sensor of this disclosure.

[0057] FIGs. 6 to 8 schematically illustrates an example configuration during operations of a wavefront sensor according to an example of this disclosure.

[0058] FIG. 9 is an image of an example configuration of a wavefront sensor according to an example of this disclosure.

[0059] FIG. 10 illustrates an example flow of operations in a method for measuring a wavefront using an example wavefront sensor of this disclosure.

[0060] FIG. 11 illustrates an example user interface presenting information related to a measured wavefront measured using an example wavefront sensor of this disclosure.

[0061] FIG. 12 illustrates an example user interface presenting information related to a measured wavefront measured using an example wavefront sensor of this disclosure.

[0062] FIG. 13 illustrates an example user interface presenting information related to a measured wavefront measured using an example wavefront sensor of this disclosure.

[0063] FIG. 14 illustrates an example user interface presenting information related to a measured wavefront measured using an example wavefront sensor of this disclosure.

[0064] FIG. 15 illustrate an example flow of operations in a method for using an example wavefront of this disclosure.

[0065] FIG. 16 is a computer architecture diagram showing a general computing system for implementing aspects of the present disclosure in accordance with one or more embodiments described herein.

[0066] FIGs. 17A to 17E illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure.

[0067] FIGs. 18A to 18C illustrate example representations of measured data from one example construction of an example w avefront sensor of this disclosure.

[0068] FIGs. 19A to 19C illustrate example representations of measured data from one example construction of an example w avefront sensor of this disclosure.

[0069] FIGs. 20A to 20D illustrate example representations of measured data from one example construction of an example w avefront sensor of this disclosure.

[0070] FIGs. 21A to 21D illustrate example representations of measured data from one example construction of an example w avefront sensor of this disclosure.

[0071] FIGs. 22A-22D illustrate example representations of measured data obtained from one example construction of an example wavefront sensor of this disclosure.DETAILED DESCRIPTION

[0072] This description provides examples, and is not intended to unnecessarily limit the scope, applicability’ or configuration of the solution of this disclosure. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementingembodiments of the solution. Various changes may be made in the function and arrangement of elements. Thus, various embodiments may omit, substitute, and / or add various procedures or components as appropriate. For instance, aspects and elements described with respect to certain embodiments may be combined in various other embodiments. It should also be appreciated that the following systems, devices, and components may individually or collectively be components of a larger system, wherein other procedures may take precedence over or otherwise modify their application.

[0073] Disclosed herein are systems, devices, and methods relating to wavefront sensors with aperture masks, diffusers, and / or cameras, and methods of making and using the same. Systems of this disclosure can include a wavefront sensor with significantly higher dynamic range than previously known wavefront sensors. More specifically, the present wavefront sensors measure the wavefront of incident light by separating the light into discrete, measurable sub-regions. Measuring the direction of propagation of the respective sub-regions then provides an array of wavefront surface normal vectors, or instantaneous subsampled gradients of the wavefront. From this information, the overall beam shape can be calculated.

[0074] It must also be noted that, as used in the specification and the appended claims, the singular forms ‘'a,” '‘an” and "the" include plural referents unless the context clearly dictates otherwise.

[0075] In this disclosure, the term “comprising'’ is synonymous with “including,’" “having,” “containing.” or “characterized by.” These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps. By using any of these terms, it is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0076] In this disclosure, the phrase '‘consisting of’ excludes any element, step, or ingredient not specified in the claim. When this phrase appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

[0077] In this disclosure, the phrase “consisting essentially of’ limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristic(s) of the claimed subj ect matter.

[0078] In this disclosure, where publications are referenced, the disclosures of these publications in their entireties are hereby incorporated by reference into this application.

[0079] In this disclosure, relative terms, such as “about,” “substantially,” or “approximately” are used to indicate a possible variation of ±10% in the stated value.

[0080] As used herein, “dynamic range” is intended to refer to the ratio between resolution and range. Dynamic range refers to the ability to measure thousands or waves of error with the same accuracy as measuring one wave of error.

[0081] A “high dynamic range” is intended to mean a high resolution across a relatively large range. In some examples, a high dynamic range can mean sub-wave wavefront resolution and approximately <10 arcsecond angular resolution, with a measurement range of several millimeters and several degrees. In some aspects, high dynamic range can refer to the relationship between measurement sensitivity and measurement range. For example, example systems of this disclosure can have relatively high sensitivity whether its measuring approximately 0.000 to approximately 0.001 degrees, or approximately 5.000 to approximately 5.001 degrees. In some aspects, high dynamic range can refer to approximately 0.0 to approximately 0.1 microns of wavefront curvature, or approximately 1000 to approximately 1000.1 microns of wavefront curvature. In some aspects, example wavefront sensors of this disclosure can be configured for high dynamic ranges in applications where tilt or wavefront magnitude is treated as a “signal” and resolution / sensitivity are the “noise” and this noise is most often unaffected by the signal magnitude.

[0082] As used herein, to “measure” a wavefront can encompass capturing an image of sub-beams of a wavefront, analyzing the image, and calculating the wavefront based on the analysis.

[0083] In describing example embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. It is also to be understood that the mention of one or more steps of a method does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Steps of a method may be performed in a different order than those described herein without departing from the scope of the disclosed technology. Similarly, it is also to be understood that the mention of one or more components in a device or system does not preclude the presence of additional components or intervening components between those components expressly identified.

[0084] The following examples illustrate the various embodiments of the present disclosure. Those skilled in the art will recognize many variations that are within the spirit of the present disclosure and scope of the claims.

[0085] . In some aspects, the sub-regions of a highly aberrated beam may have a large range of directional vectors. As recognized by the present inventors, the ability to accurately measure a relatively large range of sub-region vectors (e.g., several degrees of angle range, illustratively on the order of about ten degrees, e.g., about ±5-10 degrees) can be one key to measuring relatively large wavefront errors ( e.g., errors on the order of tens to thousands of waves, e.g., on the order of tens to hundreds of waves, or on the order of hundreds to thousands of waves); and / or wavefronts with relatively large tilts (e.g., tilts on the order of several degrees, illustratively on the order of about ten degrees, e.g., about ±5-10 degrees).

[0086] The example sensor systems of this disclosure may be configured to measure relatively large wavefront errors that are too large for a typical interferometer to measure, for example because interference fringes may be too dense. The present sensor also or alternatively may be configured to measure relatively large tilts that are too large for a typical Shack-Hartmann or autocollimator to measure, for example because the tilt may move the light outside of the measurement area. As such, the present sensor may be considered to have a high dynamic range.

[0087] Qualitatively, a high dynamic range wavefront sensor has a greater measurement range than an interferometer, and a greater angular measurement range than an autocollimator. In comparison, the previously known wavefront sensors described have a significantly lower dynamic range, e.g., less ability to measure large wavefront errors or lower wavefront errors.

[0088] Example components of the present wavefront sensor may include an aperture mask, a lenslet array, a diffuser, and a camera. For example, FIG. 1 schematically illustrates components of an example configuration of an example wavefront sensor system 100. More specifically, system 100 illustrated in FIG. 1 includes a mask 110, a diffuser 122 (e.g., a fluorescing diffuser for use on non-visible wavelengths of light), a lenslet array 121 for direct imaging of spots, and a camera 130 for imaging. In some examples, diffuser 122 can be configured to accommodate various beam dimensions, position, and aberrations. Mask 110 can be configured to receive incident light having a wavefront to be measured. For example, system 100 can include a light source 140 of collimated light (such as a laser that can include collimation optics) and a beamsplitter 150. In some aspects, source 140 can be configured to generate collimated light having any suitable wavelength that is visible to camera 130 (illustratively, 415-532nm). In some aspects, source 140 can be a coherent source and / or include a tight wavelength band. In some aspects, source 140 can include a fiber-coupled LED, continuous-wave (CW) laser, or pulsed laser.

[0089] In some aspects, beamspliter 150 can reflect light from source 140 to a surface the wavefront from which is to be measured, e.g., measurement surface 190. Beamspliter 150 can receive light that is reflected (e.g., specularly) by measurement surface 190 and can transmit such light which then is incident on mask 110. In some examples, beamspliter 150 may include a cube beamspliter or a plate beamspliter. Beamspliter 150 can transmit and reflect the reflect light in any suitable ratio, illustratively to transmit about half of the received light and to reflect about half of the received light (e.g., a 50 / 50 beamspliter). In some aspects, source 140 and / or beamspliter 150 can be omited, and mask 110 can receive light that is transmited by an optical component generating a wavefront to be measured.

[0090] In some aspects, mask 110 can be a spot mask with irregularly spaced apertures that respectively transmit sub-beams of the incident light onto lenslet array 121 having wavelength Xi. Lenslet array 121 can include lenslets that include similar or the same focal lengths in a plane. Mask 110 can include an array of apertures (which also may be referred to as pinholes) that segment incident light into sub-beams. In some aspects, aperture mask 110 can be ’ irregular" because it can include irregularly spaced apertures. In some aspects, the aperture array may have a unique, non-repeating pattern such that a sub-region of a certain size is unique across the array. In some aspects, spots of light transmited by mask 110 can be identified by the patern of surrounding spots. In some examples, mask 110 can include a printed pattern (e.g., a chrome pattern) on a substrate (e.g.. glass), such as a chrome aperture array on a fused silica substrate using a photolithography process, or a thin metal with lasercut patern. In some aspects, mask 110 can be formed of metal and any patern can be formed therein (e.g., cut, etched, etc.), into the metal. In some aspects, mask 110 can include at least one of copper, aluminum, gold, silver, platinum, and titanium. In some aspects, aspects of mask 110 can be tailored for according to parameters, such as aperture diameter, spacing, overall dimensions, etc. In some aspects, individual lenslets of array 121 collect and focus the light at wavelength Z2 to diffuser 122. Array 121 can cany' the non-repeating bi nan patern from mask 110.

[0091] In some examples, there is sufficient space between mask 110, array 121, and / or diffuser 122 to allow for the projected light to move on to array 121 and / or diffuser 122. depending on the configuration. In some examples, the spacing between mask 110, array 121, and / or diffuser 122 can be between 40-75mm. In some aspects, diffuser 122 and / or array 121 can be located in the focal plane of camera 130. Camera 130 can be configured to obtain a digital image to measure the related wavefront (e.g., a digital image of diffuser 122 and / or lenslet array 121 if diffuser 122 is not included in the example system). In some aspects,camera 130 can obtain a digital image of the incident light the sub-beams of which mask 110 transmits.

[0092] In some aspects, camera 130 can be operably coupled to a system controller 160. Controller 160 can be configured to electronically receive the digital image from camera 130. Controller 160 can be configured to measure the wavefront of the incident light based on the digital image, e.g., to measure the tilt and / or wavefront error of the incident light. Some setups may include a network switch or hub to allow for controller 160 to communicate with multiple cameras. Controller 160 can capture digital images from camera 130 and pass the image to a post-processing sequence performed by controller 160. The post-processing sequence can analyze the image to find the sub-beams (e.g., spots) projected on array 121 and diffuser 122. determine the sub-beam vectors associated with each spot, and calculate the wavefront surface.

[0093] Controller 160 can be implemented using any suitable combination of digital electronic circuitry, integrated circuitry7, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), central processing units (CPUs), graphical processing units (GPUs), computer hardware, firmware, software, and / or combinations thereof. For example, one or more functionalities of controller 160 may be implemented in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to. a storage system, at least one input device, and at least one output device. The programmable system or computing system can include clients and servers, such as in the example of FIG. 16. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0094] These computer programs, which can also be referred to as modules, programs, software, software applications, applications, components, or code, can include machine instructions for a programmable processor, and / or can be implemented in a high-level procedural language, an object-oriented programming language, a functional programming language, a logical programming language, and / or in assembly / machine language. As used herein, the terms “memory ” and “computer-readable medium” refer to any computer program product, apparatus and / or device, such as magnetic discs, optical disks, solid-state storage devices, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and / or data to a programmable data processor, including a machine-readablemedium that receives machine instructions as a computer-readable signal. The term ‘‘computer- readable signal" refers to any signal used to provide machine instructions and / or data to a programmable data processor. The computer-readable medium can store such machine instructions non-transitorily, such as would a non-transient solid-state memon or a magnetic hard drive or any equivalent storage medium. The computer-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores.

[0095] The computer components, software modules, functions, data stores and data structures can be connected directly or indirectly to each other in order to allow the flow of data needed for their operations. It is also noted that a module or processor includes but is not limited to a unit of code that performs a software operation, and can be implemented for example as a subroutine unit of code, or as a software function unit of code, or as an object (as in an object-oriented paradigm), or as an applet, or in a computer script language, or as another type of computer code. The software components and / or functionality can be located on a single computer or distributed across multiple computers and / or the cloud, depending upon the situation at hand.

[0096] In one nonlimiting example, controller 160 may be implemented using a computing device architecture, such as the system shown in FIG. 16 herein. In such architecture, a bus (not specifically illustrated) can serve as the information highway interconnecting the other illustrated components of the hardware. The system bus can also include at least one communication port (such as a network interface) to allow for communication with external devices either physically connected to the computing system or available externally through a wired or wireless network. Controller 160 may be implemented using a CPU (central processing unit) (e.g., one or more computer processors / data processors at a given computer or at multiple computers) that can perform calculations and logic operations required to execute a program. Controller 160 may include a non-transitory processor-readable storage medium, such as read only memory (ROM) and / or random access memory (RAM) in communication with the processor(s) and can include one or more programming instructions for the operations provided herein, e.g., for implementing any of the herein disclosed operations. Optionally, the memory may include a magnetic disk, optical disk, recordable memory' device, flash memory, or other physical storage medium. To provide for interaction with a user, controller 160 may include or may be implemented on a computing device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display)monitor) for displaying information obtained to the user and an input device such as keyboard and / or a pointing device (e.g., a mouse or a trackball) and / or a touchscreen by which the user can provide input to the computer.

[0097] In some aspects, diameter, spacing, and dimensions can be selected based on incident light being measured, expected aberrations in the wavefront, as well as how much the light is expected to tilt and / or decenter. In some aspects, mask 110 can accommodate the expected potential position of the incident light. For example, if the incident light is a 10mm diameter beam and can move around approximately + / - 20mm on the mask plane, then mask 110 can be at least approximately 50 x 50mm. In some aspects, the aperture’s diameter and spacing can be sized to maximize the number of projected spots, without causing spots to overlap. In some aspects, if the spots are too small and / or close together, they can begin to blur due to diffraction effects. In some aspects, apertures can be about approximately 100-500 microns in diameter. The smaller and closer the apertures are, the more can be added to mask 110. Apertures can be circular, although other shapes may be used such as oval, square, rectangular, or the like.

[0098] In some aspects, apertures can be approximately 250um in diameter with a center-to-center spacing of approximately 500um. In some aspects, mark parameters result in sufficiently sharp spots on diffuser 122, e.g., when diffuser 122 is a maximum of approximately 75mm from mask 110 and the incident light. In some aspects, apertures center-to-center distance can be increased if the expected wavefront could cause the projected spots to overlap. Overlapping is possible when the projected light through neighboring apertures is converging.

[0099] In one example operation of system 100, diffuser 122 diffuses incident light from array 121 such that discrete spots appear on diffuser 122 and can be imaged by camera 130. In some aspects, dimensions and position of diffuser 122 along the optical axis can be optimized for each application. For example and without limitation, the greater the distance between mask 110, array 121 and / or diffuser 122, the more the spots will displace per unit angle. In some aspects, a greater the distance between mask 110, array 121, and / or diffuser 122 can cause the projected spots to move a greater distance from their null position. However, diffraction effects can blur the spots if diffuser 122 is too far. In some aspects, camera 130 can be configured to image diffuser 122 and can be large enough to accommodate the incident light initially transmitted to array 121 and focused on diffuser 122.

[0100] In some aspects, sensor size, lens focal length, and working distance of camera 130 can be optimized depending on the system parameters. For example, camera 130 can include sufficient resolution to resolve the sub-beams imaged onto diffuser 122. To providesufficient resolution, the sensor(s) of camera 130 can have as many pixels as needed to provide such resolution, and diffuser 122 preferably fills as much of the camera’s field of view (FOV) as practicable. In some aspects, example wavefront sensor systems of this disclosure, including system 100, can include a relatively large FOV, which is understood as the acceptance angles or field angles that the related system can measure. In some aspects, system 100 can have a relatively large FOV such that system 100 can measure light that enters its aperture and ends up on one or more respective components, such as array 121 and / or diffuser 122. In some aspects, system can have a relatively large FOV of approximately + / - 10 degrees though system 100 can be configured with a larger or smaller FOV.

[0101] In some aspects, a plurality of cameras 130 can be used to image diffuser 122 for increased resolution and / or larger diffusers. For example, cameras 130 can be extrinsically calibrated relative to each other to determine how to stitch their images together in postprocessing. In some aspects, cameras 130 can have overlapping fields of view such that they can see some of the same projected spots. In this example, the reconstructed wavefront from each camera 130 can be combined by aligning the shared datapoints (e.g., spots). Cameras 130 in this example can have intrinsic and extrinsic parameters that are calibrated to best postprocess the image. Techniques for calibrating camera parameters are known in the art.

[0102] In the system 100 of FIG. 1 any suitable number and type(s) of beam shaping optics can be included. For example, system 100 can include a collimated light source 140, one or more fold mirrors, and / or one or more beam splitters 150 to reflect light off of a measurement surface 190 before entering system 100. In some aspects, the sensor 100 can receive light directly from an external system. In some aspects, fold mirrors can be located somewhere between the collimated source and the beamsplitter 150, for example to steer the beam for packaging reasons. In some aspects, system 100 can include housing 170 in which mask 110, lenslet array 121, diffuser 122, and / or camera 130 are located. As can be appreciated in view of subsequent example sensor configurations of this disclosure, diffuser 122 and / or mask 110 are not necessarily required in each sensor configuration and system 100 and its housing 170 are simply one example implementation. Controller 160 can be located within the 170 and coupled to camera 130 via a direct electrical connection (e.g.. cabling), or alternatively may be located remotely from the housing and coupled to camera 130 via a wireless connection (e.g., Wi-Fi, Bluetooth, or the like).

[0103] FIG. 2 schematically illustrates only certain components of another example configuration of an example wavefront sensor system 200. Similar to system 100, system 200 can include a mask 210, diffuser 222, and lenslet array 221 for direct imaging of spots, and acamera 230 for imaging. Mask 210 can be configured to receive incident light having a wavefront to be measured, just as with system 100. Mask 210 can be a spot mask with irregularly spaced apertures that respectively transmit sub-beams of the incident light onto lenslet array 221 having wavelength Xi. Mask 210 can include an array of apertures that segment incident light into sub-beams, as shown in FIG. 2. Just as in mask 110, mask 210 can be irregular having a unique, non-repeating pattern such that a sub-region of a certain size is unique across its aperture array. In some aspects, spots of light transmitted by mask 210 can be identified by the pattern of surrounding spots. Lenslets of array 221 can collect and focus the light at wavelength Z2 to diffuser 222 whereby array 221 can cany7the non-repeating binary7pattern from mask 210. Camera 230 of system 200 can be configured to electronically capture a digital image of diffuser 222 so that an associated controller can measure the wavefront of the incident light based on the captured digital image, e.g., to measure the tilt and / or wavefront error of the incident light.

[0104] FIG. 3 schematically illustrates aspects of another example configuration of an example wavefront sensor system 300. System 300 can include a diffuser 310 and lenslet array 321 for direct imaging of spots, and a camera 330 for imaging but may not necessarily include a diffuser. Lenslet array 321 can be an array of microlenses that collect and focus sub-beams of the incident light onto diffuser 310 having wavelength Xi. Lenslet array 321 can include an array of lenslets that segment and focus incident light onto diffuser 310. Lenslet array 321 can include a unique, non-repeating pattern of missing and / or obscured lenslets such that a subregion of a certain size is unique across lenslet array 321. In some aspects, spots of light transmitted by lenslet array 321 onto diffuser 310 can be identified by the pattern of lenslet array 321. Lenslets of array 321 can collect and focus the light whereby array 321 can carry its non-repeating pattern of missing and / or obscured areas. Camera 330 of system 300 can be configured to electronically capture a digital image of lenslet array 321 so that an associated controller (e.g., similar to controller 160) can measure the wavefront of the incident light based on the captured digital image, e.g., to measure the tilt and / or w avefront error of the incident light.

[0105] FIG. 4 schematically illustrates components of an example configuration of an example wavefront sensor system 400. More specifically, system 400 illustrated in FIG. 4 includes a mask 410, a lenslet array 421 for direct imaging of spots, and a camera 430 having a camera sensor 435. In some examples, mask 410 can be configured to receive incident light having a wavefront to be measured (e.g.. such as collimated light from light source 140 as described in previous system 100). In some aspects, mask 410 can be a spot mask withirregularly spaced apertures that respectively transmit sub-beams of the incident light onto lenslet array 421 having wavelength Xi. Mask 410 can include an array of apertures that segment incident light into sub-beams, as shown in FIG. 4. Similar to previous masks of this disclosure, mask 410 can be irregular having a unique, non-repeating pattern such that a subregion of a certain size is unique across its aperture array. In some aspects, spots of light transmitted by mask 410 can be identified by the pattern of surrounding spots. As demonstrated in FIG. 4, lenslets of array 421 can collect and focus the light at wavelength / .2to camera sensor 435 whereby array 421 can carry the non-repeating binary pattern from mask 410. Camera 430 with camera sensor 435 can be configured to electronically capture a digital image of array 421 so that an associated controller can measure the wavefront of the incident light based on the captured digital image, e.g., to measure the tilt and / or wavefront error of the incident light.

[0106] FIG. 5 schematically illustrates components of an example configuration of an example wavefront sensor system 500. More specifically, system 500 illustrated in FIG. 5 includes a lenslet array 521 for direct imaging of spots and a camera 530 having a camera sensor 535. In some examples, lenslet array 521 can be configured to receive incident light having a wavefront to be measured (e.g.. such as collimated light from light source 140 as described in previous system 100). Lenslet array 521 can include a unique non-repeating pattern of missing or obscured areas in its array of apertures that segment incident light into sub-beams, as shown in FIG. 5. As demonstrated in FIG. 5, lenslets of array 521 can collect and focus the light at a wavelength to camera sensor 535. Camera 530 can be configured to electronically capture a digital image of sensor 535 so that an associated controller (e g., similar to controller 160) can measure the wavefront of the incident light based on the captured digital image, e.g., to measure the tilt and / or wavefront error of the incident light.

[0107] FIG. 6 schematically illustrates an example wavefront sensor configuration 600 and its use to measure a tilted wavefront. In this example, the incident illustrated wavefront, whether reflected from a measurement optic or received directly, is split into sub-beams at the mask 610, which then project onto the diffuser 622. While a diffuser is shown in configuration 600, it is contemplated that configuration 600 could include a mask and / or a lenslet array in addition to diffuser 622 or in place of diffuser 622. Camera 630 can then generate an image of diffuser 622. The position of the spots 625 on the diffuser 622 is a function of the direction of propagation of the wavefront as it enters each aperture thereof. As the w avefront tilts in FIG. 6, the spots will move relative to the reference position according to the tilt angle. In some aspects, wavefront characteristics can be calculated by a controller (e.g., controller 160 of prior example system 100) based on the position of each projected spot (sub-beam of the incidentwavefront) on the diffuser relative to both its reference position and its neighboring spots. While it may appear in FIG. 6 that the spots 625 (and sub-beams) are regularly and periodically spaced, the apertures of mask 610 may be irregularly spaced and therefore the spots 625 similarly may be irregularly spaced.

[0108] FIG. 7 schematically illustrates an example wavefront sensor configuration 700 with high-dynamic range with an aberrated measurement surface 790’. In the depicted configuration, when measuring a wavefront, the imaged spots 725 in FIG. 7 must be uniquely identifiable by controller such that corresponding null positions of spots 725 can be determined, and therefore their position deltas from null. Determining the corresponding null position for any visible spot, regardless of displacement magnitude, may be important for a high dynamic range, as in the depicted example of FIG. 7, where spots 725 in the resultant image appear filled while the depicted vectors that created those spots are different.

[0109] FIG. 8 schematically illustrates an example wavefront sensor configuration 800 and its use to take multiple measurements. In this example, the wavefront sensor is shown configured to measure multiple wavefronts from multiple corresponding measurement surfaces 890” whereby incident illustrated wavefronts are split into sub-beams at the mask 810, which then project onto the diffuser 822. While diffuser 822 is shown in configuration 800, it is contemplated that configuration 800 could include a lenslet array in addition to diffuser 822 or in place of diffuser 822. Camera 830 can then generate an image of diffuser 822. The position of the spots 825 on the diffuser 822 is a function of the direction of propagation of the wavefronts as they enter each aperture thereof. Just as in prior examples, wavefront characteristics can be calculated by a controller (e.g., controller 160 of prior example system 100) based on the position of each projected spot (sub-beam of the incident wavefronts) on the diffuser 822 relative to both its reference position and its neighboring spots.

[0110] FIG. 9 shows an example wavefront sensor constructed in accordance with aspects of this disclosure. As can be seen, a collimator was used to collimate a laser beam that was directed onto a beamsplitter. The beamsplitter reflected the beam to a surface to be measured as described herein, and then transmitted the light reflected by such surface to a mask whereby the mask generated sub-beams of the incident light and projected spots onto a diffuser w hich was imaged by a calibrated camera. The digital images from the camera in the illustrated example w ere processed on a computer configured to implement operations such as described herein.[OHl] FIG. 10 schematically illustrates an example configuration 1000 of one example w avefront sensor of this disclosure. In this example, the incident wavefront is shown beingsplit into sub-beams at the mask 1010, which can be an encoded pinhole mask, which is projected with its unique pattern onto diffuser 1022. While diffuser 1022 is shown in configuration 1000, it is contemplated that configuration 1000 could include a lenslet array in addition to diffuser 1022 or in place of diffuser 1022. Camera 1030 can then generate one or more images of the pattern of diffuser 1022 (or lenslet array in those examples), such as a QHS image 1101 (where QHS is charge at high gain over a short integration time). From these images, the displacement of spots 1025 can be used to provide a vector field from which wavefront and tilt can be calculated, as in example tilted beam image 1102a and defocused example beam image 1102b. The position of the spots 1025 on the diffuser 1022 is a function of the direction of propagation of the wavefront as it enters each aperture. As discussed herein, wavefront characteristics can be calculated based on the position of each projected spot 1025 relative to both its reference position and its neighboring spots. As long as the projected subregions land with sufficient contrast, camera 1030 can image and wavefront characteristics can be determined. Based on related analytics carried out by system controller, analytical output 1103 can be displayed for further use. In some aspects, the system controller can be configured to utilize components of configuration 1000 to take measurements that would otherwise require multiple instruments or a more complex setup.

[0112] FIG. 11 schematically illustrates one example output 1103a of configuration 1000 displayable in a related user interface in communication with the system controller. Output 1103a in FIG. 11 can include a window to toggle through one or more related outputs as well as include 2D and / or 3D plots (e g., the illustrated Zemike reconstructed 3D wavefront). In some embodiments, the measured wavefront can be fit with Zemike polynomials to deconstruct individual optical aberrations (astigmatism, coma, etc.) for the purposes of optical system alignment and optimization as in example output 1103b of FIG. 12 which illustrates an example Zemike polynomials bar chart. Other outputs contemplated for display in the window can include output 1 103c (tilt measurement plots shown in FIG. 13) and output 1103d (beam intensity distribution plots shown in FIG. 14). These example outputs and the related user interface display windows are merely examples and any number of outputs and related graphs or plots are contemplated for use with the example systems of this disclosure.

[0113] FIG. 15 shows a method 1500, which can be computer-implemented, for operating or using one or more of the example wavefront configurations of this disclosure. Step 1510 of method 1500 can include passing incident light through a lenslet array and / or a mask (e.g.. a pinhole mask or any other mask of this disclosure). Step 1520 of method 1500 can include imaging (and / or reimaging), by a camera, one or more patterns of the sub-beamsof the incident light passed through the lenslet array and / or the mask. The camera can be camera 130 and / or any related camera sensor of this disclosure. Step 1530 of method 1500 can include creating a vector field by displacement of spots associated with the incident light passed through the lenslet array and / or the mask. Step 1540 of method 1500 can include calculating (e.g., by a system controller) wavefront and / or tilt based on the created vector field.

[0114] FIG. 16 is a computer architecture diagram showing a general computing system capable of implementing aspects of the present disclosure, such as the controller 160 of system 100 and related camera 130, in accordance with one or more embodiments described herein. In any of these example implementations, computer 1600 of the aforementioned may be configured to perform one or more functions associated with embodiments of this disclosure. For example, the computer 1600 may be configured to perform operations in accordance with those examples shown in FIGs. 1 to 15. It should be appreciated that the computer 1600 may be implemented within a single computing device or a computing system formed with multiple connected computing devices. The computer 1600 may be configured to perform various distributed computing tasks, in which processing and / or storage resources may be distributed among the multiple devices. The data acquisition and display computer 1650 and / or operator console 1610 of the system shown in FIG. 16 may include one or more systems and components of the computer 1600.

[0115] As shown, the computer 1600 includes a processing unit 1602 (“CPU’'), a system memory 1604, and a system bus 1606 that couples the memory 1604 to the CPU 1602. The computer 1600 further includes a mass storage device 1612 for storing program modules 1614. The program modules 1614 may be operable to analyze data, such as wavefront data and related analytics, from any herein disclosed components and / or control any related operations. The program modules 1614 may include an application 1618 for performing data acquisition and / or processing functions as described herein, for example to acquire and / or process any of the herein discussed data feeds. The computer 1600 can include a data store 1620 for storing data that may include data 1622 of data feeds from system components.

[0116] The mass storage device 1612 is connected to the CPU 1602 through a mass storage controller (not shown) connected to the bus 1606. The mass storage device 1612 and its associated computer-storage media provide non-volatile storage for the computer 1600. Although the description of computer-storage media contained herein refers to a mass storage device, such as a hard disk or CD-ROM drive, it should be appreciated by those skilled in the art that computer-storage media can be any available computer storage media that can be accessed by the computer 1600.

[0117] By way of example and not limitation, computer storage media (also referred to herein as "computer-readable storage medium” or “computer-readable storage media”) may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-storage instructions, data structures, program modules, or other data. For example, computer storage media includes, but is not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology. CD-ROM. digital versatile disks (“DVD”), HD-DVD, BLU-RAY, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer 1600. “Computer storage media”, “computer-readable storage medium” or “computer-readable storage media” as described herein do not include transitory signals.

[0118] According to various embodiments, the computer 1600 may operate in a networked environment using connections to other local or remote computers through a network 1616 via a network interface unit 1610 connected to the bus 1606. The network interface unit 1610 may facilitate connection of the computing device inputs and outputs to one or more suitable networks and / or connections such as a local area network (LAN), a wide area network (WAN), the Internet, a cellular network, a radio frequency (RF) network, a Bluetooth- enabled network, a Wi-Fi enabled network, a satellite-based network, or other wired and / or wireless networks for communication with external devices and / or systems.

[0119] The computer 1600 may also include an input / output controller 1608 for receiving and processing input from any of a number of input devices. Input devices may include one or more of keyboards, mice, sty lus, touchscreens, microphones, audio capturing devices, and image / video capturing devices. An end user may utilize the input devices to interact with a user interface, for example a graphical user interface, for managing various functions performed by the computer 1600. The bus 1606 may enable the processing unit 1602 to read code and / or data to / from the mass storage device 1612 or other computer-storage media.

[0120] The computer-storage media may represent apparatus in the form of storage elements that are implemented using any suitable technology, including but not limited to semiconductors, magnetic materials, optics, or the like. The computer-storage media may represent memory components, whether characterized as RAM, ROM, flash, or other types of technology. The computer storage media may also represent secondary' storage, whether implemented as hard drives or otherwise. Hard drive implementations may be characterized as solid state or may include rotating media storing magnetically-encoded information. Theprogram modules 1614, which include the data feed application 1618, may include instructions that, when loaded into the processing unit 1602 and executed, cause the computer 1600 to provide functions associated with one or more embodiments illustrated in the figures of this disclosure. The program modules 1614 may also provide various tools or techniques by which the computer 1600 may participate within the overall systems or operating environments using the components, flows, and data structures discussed throughout this description.

[0121] In general, the program modules 1614 may, when loaded into the processing unit 1602 and executed, transform the processing unit 1602 and the overall computer 1600 from a general-purpose computing system into a special-purpose computing system. The processing unit 1602 may be constructed from any number of transistors or other discrete circuit elements, which may individually or collectively assume any number of states. More specifically, the processing unit 1602 may operate as a finite-state machine, in response to executable instructions contained within the program modules 1614. These computerexecutable instructions may transform the processing unit 1602 by specifying how the processing unit 1602 transitions between states, thereby transforming the transistors or other discrete hardware elements constituting the processing unit 1602.

[0122] Encoding the program modules 1614 may also transform the physical structure of the computer-storage media. The specific transformation of physical structure may depend on various factors, in different implementations of this description. Examples of such factors may include but are not limited to the technology used to implement the computer-storage media, whether the computer storage media are characterized as primary or secondary storage, and the like. For example, if the computer storage media are implemented as semiconductorbased memory, the program modules 1614 may transform the physical state of the semiconductor memory, when the software is encoded therein. For example, the program modules 1614 may transform the state of transistors, capacitors, or other discrete circuit elements constituting the semiconductor memory.

[0123] As another example, the computer storage media may be implemented using magnetic or optical technology. In such implementations, the program modules 1614 may transform the physical state of magnetic or optical media, when the software is encoded therein. These transformations may include altering the magnetic characteristics of particular locations within given magnetic media. These transformations may also include altering the physical features or characteristics of particular locations within given optical media, to change the optical characteristics of those locations. Other transformations of physical media are possiblewithout departing from the scope of the present description, with the foregoing examples provided only to facilitate this discussion.

[0124] According to certain embodiments, the above-described data feeds may be stored in databases such as database servers that store master data as well as logging and trace information. The databases may also provide an API and / or API access (e.g., for open source) to the web server for data interchange based on JSON specifications. According to certain embodiments, the database servers may be optimally designed for storing large amounts of data, responding quickly to incoming requests, having a high availability and historizing master data.

[0125] In the description herein, numerous specific details are set forth. However, it is to be understood that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been show n in detail in order not to obscure an understanding of this description. References to ‘‘one embodiment,'’ “an embodiment,” “example embodiment,” “some embodiments,” “certain embodiments.” “various embodiments.” etc., indicate that the embodiment(s) of the present disclosure so described may include a particular feature, structure, or charactenstic. but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase “in one embodiment” does not necessarily refer to the same embodiment, although it may.

[0126] Throughout the specification and the claims, the following terms take at least the meanings explicitly associated herein, unless the context clearly dictates otherwise. The term “or” is intended to mean an inclusive “or.” Further, the terms “a,” “an,” and “the” are intended to mean one or more unless specified otherwise or clear from the context to be directed to a singular form. Accordingly, “a module” or “the module” may refer to one or more modules where applicable.

[0127] Unless otherwise specified, the use of the ordinal adjectives “first,” “second,” “third,” etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0128] Certain embodiments of the present disclosure are described above with reference to block and How diagrams of systems and methods and / or computer program products according to example embodiments of the present disclosure. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow' diagrams, respectively, may be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some embodiments of the present disclosure.

[0129] This disclosure is more clearly understood with corresponding studies discussed more particularly below. It is understood that data is presented herein for purposes of illustration and should not be construed as limiting the scope of the disclosed technology in any way or excluding any alternative or additional embodiments.

[0130] In one example, FIGs. 17A to 17F illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure. Specifically, the example of FIGs. 17A to 17F included a 45 mm collimated beam used to directly measure wavefront and tilt, such as a lens assembly and / or parabolic mirror system. In the test, live feedback for lens and mirror alignment was observed and no compression optics were required. FIG. 17A illustrates a plot related to the measured wavefront, FIG. 17B illustrates a plot related to Zemike surface, FIG. 17C illustrates a plot related to measured wavefront and tilt removed, FIG. 17D illustrates a bar plot showing Zemike coefficient (pm) versus various high-order aberrations, and FIG. 17E illustrates beam tilt of the test. In FIGS. 17A to 17E, it was observed that wavefront peak-to-valley (PV) was approximately 114.69 pm while wavefront PV with tilt removed was approximately 0.130 pm. The X Tilt was approximately -0.4570 degrees and Y Tilt was approximately -0. 1867 degrees.

[0131] In another example, FIGs. 18A to 18C illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure. Specifically, the example of FIGs. 18A to 18C was directed to determine accuracy of the configuration by measuring the beam deviation as light refracts through a rotating wedge. The wedge directed the beam approximately 2°, which traced a cone when rotated with approximately 4° full angle. The measured tilt was directed to trace a circle with a radius equal to the wedge beam deviation. FIG. 18A illustrates a precession plot related to Y tilt (degrees) versus X tilt (degrees), FIG. 18B illustrates a plot related to tilt angle versus wedge rotation with one curve corresponding to X tilt and another curve corresponding to Y tilt, and FIG. 18C illustrates a plot related to theta (precession radius noise) as to theta (degrees) versus wedge rotation (deg). In FIGS. 18A to 18C, the system successfully demonstrated relatively high resolution tilt measurement, even with approximately 4° of beam deviation and tilt error standard deviation was observed as approximately 0.00008 degrees (1.4 prad).

[0132] In another example, FIGs. 19A to 19C illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure. Specifically, the example of FIGs. 19A to 19C was directed to determine the “wobble” of a bearing by measuring the light reflected by a mirror that is rotating on the bearing. In this example, the measured angle of the reflected light was configured to trace a circle when the bearing was perfect. Any repeatable deviation from a circle was due to the wobble of the bearing. FIG. I9A illustrates a precession plot related to Y tilt (degrees) versus X tilt (degrees), FIG. 19B illustrates a plot related to tilt angle versus wedge rotation with one curve corresponding to X tilt and another curve corresponding to Y tilt, and FIG. 19C illustrates a plot related to theta (precession radius noise) as to theta (degrees) versus wedge rotation (deg). In FIGs. 19A to 19C, the system successfully demonstrated relatively high resolution wobble characterization with wobble magnitude being + / -0.0005 degrees (9 microradians) and random noise being approximately 0.0001 degrees (1.8 microradians).

[0133] In another example, FIGs. 20 A to 20D illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure. Specifically, the example of FIGs. 20A to 20D was directed to measure radius of curvature and reflected wavefront of a cylindrical and concave mirror with 50 mm focal length. In this example, FIG. 20A illustrates a plot related to measured wavefront error (WFE), FIG. 20B illustrates a plot related to Zemike fit, FIG. 20C illustrates a plot related to measured WFE with Zemike terms removed, and FIG. 20D illustrates a bar plot showing Zemike coefficient (pm) versus various high-order aberrations. In FIGs. 20A to 20D, wavefront PV was observed as approximately 1.940 millimeters, radius of curvature was observed as approximately 82.5 millimeters, and spherical aberration was observed as approximately 13.2 micron.

[0134] In another example, FIGs. 21A to 21D illustrate example representations of measured data from one example construction of an example wavefront sensor of this disclosure. Specifically, the example of FIGs. 21 A to 21 D was directed to measure radius of curvature and reflected wavefront of a cylindrical and concave mirror with 50 mm focal length. In this example, FIG. 21 A illustrates a plot related to measured WFE. FIG. 21 B illustrates a plot related to Zemike fit. FIG. 21 C illustrates a plot related to measured WFE with Zemike terms removed, and FIG. 21 D illustrates a bar plot showing Zemike coefficient (pm) versus various high-order aberrations. In FIGs. 21A to 21D, wavefront PV was observed as approximately .878 micron.

[0135] In another example, FIGs. 22A to 22D illustrate example representations of measured data from one example construction of an example wavefront sensor of thisdisclosure. Specifically, the example of FIGs. 22A to 22D was directed to diffractive optics to measure the light transmitted through a 2D diffractive beam splitter and a diffractive beam splitter that created a 7 x 7 grid with approximately F separation. In this example, FIG. 22A illustrates the example scatter plot summarizing measured tilt of diffracted beams that includes Y tilt versus X tilt, FIG. 22B illustrates a plot related to unit vectors or diffracted beams, FIG. 22C illustrates a plot related to wavefront of each beam, and FIG. 2 ID illustrates a plot related to each beam with tilt removed. In FIGs. 22A to 22D, multiple beams (here 49 individual beams) were analyzed w ith a single measurement to determine tilts and vectors of each beam. The system successfully determined the wavefront of each beam, with and without tilt.

[0136] From the foregoing, it will be appreciated that multiple aspects of the present subject matter alone or in combination provide for wavefront sensors having improved usability and dynamic range as compared to previously known sensors. For example, the present subject matter includes a hardware aspect. Additionally, or alternatively, the present subject matter includes one or more steps of a method. Such aspects may include, but are not limited to, any suitable combination of one or more of the following: mask design, mask focal length, and / or imaging camera(s) parameters for desired application; and / or image processing algorithm for each measurement of incident light. Such algorithm may include any combination of one or more of the following: detect features in images; identify features, and determine displacements with their respective null positions; determine vectors represented by feature displacements; output vector field, mean vector, wavefront, and / or Zemike polynomials; and / or multiple wavefronts measured simultaneously.

[0137] It is to be understood that any respective features / examples of each of the aspects of the disclosure as described herein may be implemented together in any appropriate combination, and that any features / examples from any one or more of these aspects may be implemented together with any of the features of the other aspect(s) as described herein in any appropriate combination to achieve the benefits as described herein.

[0138] While various illustrative examples are described above, it will be apparent to one skilled in the art that various changes and modifications may be made therein without departing from the invention. The appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Claims

CLAIMSWhat is claimed is:

1. A wavefront sensor for measuring a wavefront, the sensor comprising: a mask configured to receive incident light of the wavefront and comprising irregularly spaced apertures that respectively transmit sub-beams of the incident light; a lenslet array positioned to receive sub-beams of the incident light from the mask so that individual lenslets of the lenslet array collect and focus the sub-beams of incident light; a camera having a focal plane of the mask and the lenslet array, the camera configured to obtain a digital image of the lenslet array and / or the mask related to the incident light; and a controller configured to measure the wavefront of the incident light based at least partially on the digital image.

2. The sensor of claim 1 , wherein the controller is configured to measure the wavefront without a tilt.

3. The sensor of claim 1, wherein the controller is configured to measure tilt of a plurality of diffracted beams.

4. The sensor of claim 1, wherein the controller is configured to measure a wavefront error of the incident light.

5. The sensor of claim 1, wherein the controller is configured to measure a wavefront error of the incident light with Zemike terms removed.

6. The sensor of claim 1, wherein the controller is configured to measure beam deviation as light refracts.

7. The sensor of claim 1, wherein the controller is configured to measure precession radius noise.

8. The sensor of claim 1, wherein the controller is configured to measure bearing wobble.

9. The sensor of claim 1 , further comprising a diffuser between the lenslet array and the camera.

10. The sensor of claim 1, wherein the sensor comprises a field-of-view of approximately + / - 10 degrees.

11. A method for measuring a wavefront, comprising: passing, at a lenslet array, incident light of the wavefront or sub-beams of the incident light of the wavefront; imaging, by a camera, one or more patterns of sub-beams the incident light passed through the lenslet array to create one or more digital images; and measuring, by a system controller and based on the one or more digital images, the wavefront of the incident light.

12. The method of claim 11. further comprising: generating collimated light having the wavefront, wherein a source of collimated light comprises a laser.

13. The method of claim 11. further comprising: using a beamsplitter to reflect light from a light source to a surface the wavefront from which is to be measured, to receive light that is reflected, and to transmit such light which then is incident on the lenslet array.

14. The method of claim 11. wherein the lenslet array receives light that is transmitted by an optical component generating the wavefront to be measured.

15. The method of claim 11, wherein the wavefront is measured based on positions of the sub-beams on the lenslet array relative to both respective reference positions and neighboring sub-beams.

16. The method of claim 11, further comprising: measuring, by the system controller, a wavefront error of the incident light.

17. The method of claim 11, further comprising:measuring, by the system controller, a wavefront error of the incident light with Zemike terms removed.

18. The method of claim 11, further comprising: measuring, by the system controller, beam deviation as light refracts.

19. The method of claim 11. further comprising: measuring, by the system controller, precession radius noise.

20. The method of claim 11. further comprising: measuring, by the system controller, bearing wobble.

21. A computer-implemented system, comprising: one or more memories storing instructions; a system controller; and one or more processors configured to execute the instructions to perform operations configured to measure a wavefront, the operations comprising: causing, by the system controller, incident light of the wavefront or sub-beams of the incident light of the wavefront to pass at a lenslet array; imaging, by a camera, one or more patterns of sub-beams the incident light passed through the lenslet array to create one or more digital images; and measuring, by the system controller and based on the one or more digital images, the wavefront of the incident light.

22. A wavefront sensor for measuring a wavefront, comprising: a diffuser; a lenslet array comprising an array of microlenses that collect and focus sub-beams of incident light onto the diffuser; a camera having a focal plane of the diffuser and the lenslet array, the camera configured to obtain a digital image of the lenslet array and / or the diffuser related to the incident light; and a controller configured to measure the wavefront of the incident light based at least partially on the digital image.

Images