Interferometry with computer generated holograms (CGH) has evolved to be a standard technology for optical testing and metrology. By controlling the phase of the diffracted light, CGHs are capable of generating reference wavefronts of any desired shape, which allows using of interferometers for measuring complex aspheric surfaces. Fabrication errors in CGHs, however, cause phase errors in the diffracted wavefront, which directly affects the accuracy and validity of the interferometric measurements. Therefore, CGH fabrication errors must be either calibrated or budgeted. This dissertation is a continuation and expansion of the analysis and calibration of the wavefront errors caused by CGH in optical testing. I will focus on two types of error: encoding error and etching variation induced errors. In Topic one, the analysis of wavefront error introduced by encoding the CGH is discussed. The fabrication of CGH by e-beam or laser writing machine specifically requires using polygon segments to approximate the continuously smooth fringe pattern of an ideal CGH. Wavefront phase errors introduced in this process depend on the size of the polygon segments and the shape of the fringes. We propose a method for estimating the wavefront error and its spatial frequency, allowing optimization of the polygon sizes for required measurement accuracy. This method is validated with both computer simulation and direct measurements from an interferometer. In Topics two, we present a new device, the Diffractive Optics Calibrator (DOC), for measuring etching parameters, such as duty-cycle and etching depth, for CGH. The system scans the CGH with a collimated laser beam, and collects the far field diffraction pattern with a CCD array. The relative intensities of the various orders of diffraction are used to fit the phase shift from etching and the duty cycle of the binary pattern. The system is capable of measuring variations that cause 1 nm peak-to-valley (P-V) phase errors. The device will be used primarily for quality control of the CGHs. DOC is also capable of generating an induced phase error map for calibration. Such calibration is essential for measuring freeform aspheric surfaces with 1 nm root-mean-square (RMS) accuracy.

Interferometry with computer generated holograms (CGH) has evolved to be a standard technology for optical testing and metrology. By controlling the phase of the diffracted light, CGHs are capable of generating reference wavefronts of any desired shape, which allows using of interferometers for measuring complex aspheric surfaces. Fabrication errors in CGHs, however, cause phase errors in the diffracted wavefront, which directly affects the accuracy and validity of the interferometric measurements. Therefore, CGH fabrication errors must be either calibrated or budgeted. This dissertation is a continuation and expansion of the analysis and calibration of the wavefront errors caused by CGH in optical testing. I will focus on two types of error: encoding error and etching variation induced errors. In Topic one, the analysis of wavefront error introduced by encoding the CGH is discussed. The fabrication of CGH by e-beam or laser writing machine specifically requires using polygon segments to approximate the continuously smooth fringe pattern of an ideal CGH. Wavefront phase errors introduced in this process depend on the size of the polygon segments and the shape of the fringes. We propose a method for estimating the wavefront error and its spatial frequency, allowing optimization of the polygon sizes for required measurement accuracy. This method is validated with both computer simulation and direct measurements from an interferometer. In Topics two, we present a new device, the Diffractive Optics Calibrator (DOC), for measuring etching parameters, such as duty-cycle and etching depth, for CGH. The system scans the CGH with a collimated laser beam, and collects the far field diffraction pattern with a CCD array. The relative intensities of the various orders of diffraction are used to fit the phase shift from etching and the duty cycle of the binary pattern. The system is capable of measuring variations that cause 1 nm peak-to-valley (P-V) phase errors. The device will be used primarily for quality control of the CGHs. DOC is also capable of generating an induced phase error map for calibration. Such calibration is essential for measuring freeform aspheric surfaces with 1 nm root-mean-square (RMS) accuracy.

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In conventional laser material processing systems the energy distribution available at the work-piece is restricted to a focused spot. Such energy distributions are often not the most efficient or effective for many applications. This thesis proposes the utilisation of diffractive optical elements to shape high power laser beams into complex intensity distributions, thereby overcoming the limitations of conventional laser systems. The research presented demonstrates, for the first time, how processing characteristics and efficiency can be significantly enhanced by tailoring the incident laser energy distribution to take into account the process being undertaken, the material and geometry of the work-piece.

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As techniques for manufacturing and metrology advance, optical systems are being designed with more complexity than ever before. Given these prescriptions, alignment and calibration can be a limiting factor in their final performance. Computer generated holograms (CGHs) have several unique properties that make them powerful tools for meeting these demanding tolerances. This work will present three novel methods for alignment and calibration of optical systems using computer generated holograms. Alignment methods using CGHs require that the optical wavefront created by the CGH be related to a mechanical datum to locate it space. An overview of existing methods is provided as background, then two new alignment methods are discussed in detail. In the first method, the CGH contact Ball Alignment Tool (CBAT) is used to align a ball or sphere mounted retroreflector (SMR) to a Fresnel zone plate pattern with micron level accuracy. The ball is bonded directly onto the CGH substrate and provides permanent, accurate registration between the optical wavefront and a mechanical reference to locate the CGH in space. A prototype CBAT was built and used to align and bond an SMR to a CGH. In the second method, CGH references are used to align axi-symmetric optics in four degrees of freedom with low uncertainty and real time feedback. The CGHs create simultaneous 3D optical references where the zero order reflection sets tilt and the first diffracted order sets centration. The flexibility of the CGH design can be used to accommodate a wide variety of optical systems and maximize sensitivity to misalignments. A 2-CGH prototype system was aligned multiplied times and the alignment uncertainty was quantified and compared to an error model. Finally, an enhanced calibration method is presented. It uses multiple perturbed measurements of a master sphere to improve the calibration of CGH-based Fizeau interferometers ultimately measuring aspheric test surfaces. The improvement in the calibration is a function of the interferometer error and the aspheric departure of the desired test surface. This calibration is most effective at reducing coma and trefoil from figure error or misalignments of the interferometer components. The enhanced calibration can reduce overall measurement uncertainty or allow the budgeted error contribution from another source to be increased. A single set of sphere measurements can be used to calculate calibration maps for closely related aspheres, including segmented primary mirrors for telescopes. A parametric model is developed and compared to the simulated calibration of a case study interferometer.

Since 1962, a photographic invention by Gabriel Lippmann (1845-1921), his Nobel Prize winning interference colour photograph of 1891, has been cited by physicists as the antecedent of the three-dimensional hologram. However, Dennis Gabor (1900-1979) in his original publications on the hologram of 1948 and 1949 did not cite Lippmann’s work. This thesis explores how the hologram that featured in Gabor’s original theory, as an imaging technique to improve the electron-microscope, was significantly different from the hologram for which Gabor was awarded the Nobel Prize for Physics in 1971. The citation of Lippmann’s work as the antecedent to the hologram confirmed that the hologram was to be seen as a three-dimensional photograph, and attempted to give the invention a progressive historical lineage that would conform to photography’s existing history. This popular narrative, as demonstrated in this text, could overlook the pursuit of the hologram for Cold War surveillance by researchers at the University of Michigan on behalf of the United States military. This technology was, from 1955, engaged with aerial radar image processing, a significant application that was classified and hidden from the public, and initially from Gabor himself. Two researchers at the University of Michigan, Emmett Leith (1927–) and Juris Upatnieks (1936–) attracted the attention of the popular press for their development of a three-dimensional laser hologram. This thesis reveals the fragmented nature of the new discipline at the peak of holography’s popularity. This analysis explores some of the historical traits between the two Nobel Prize winning inventions, the Lippmann photograph and the hologram, that were exploited to promote a new imaging medium to the public. In presenting these technologies as images the text also reviews devices and papers––some cited within the popular Lippmann-to Gabor historical narrative––by father and son Frederic (1856-1937) and Herbert Ives (1882-1953), that have competed to produce a three-dimensional full-colour image.

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Holograms are a newer form of digital media. Digital media is changing traditional arts. They are also shaping how people play. How holograms have influenced play and crafting is not well understood. This project used dollhouses to examine how crafting a digital dollhouse relates to crafting a tangible dollhouse. Further, the project examined how playing in both dollhouses compares. Two dollhouses were created by the author/craftsperson. She reflects on her craft practices, relating her two experiences. Adult play testers describe their play experience in the holographic dollhouse and tangible dollhouse. The author’s experience creating is analyzed through its material, social and playful aspects. She found each dollhouses had both material and immaterial qualities. She preferred playing alone in the dollhouses and found the creation process of the dollhouses was both play and work at the same time. The play testers’ experience was also examined through material, social and playful characteristics. Their responses to the survey indicated that grasping objects was difficult in both dollhouses. They reported that they would have preferred to play alone in the dollhouses and that both dollhouses felt playful. An area of potential research that was uncovered involved a question of ownership of the dollhouse and how this may have changed the results of the study.