The research described in this dissertation conclusively demonstrates the superior qualitative and quantitative performance of spectroscopic systems which employ a new class of optical detectors--charge transfer device (CTD) detectors. An overview of the operation and characteristics of these detectors, as well as theoretical models predicting their performance are presented. The evaluation of a unique prototype single element CID detector, a commercially available linear CCD detector, and a prototype two-dimensional CCD detector are described. Outstanding characteristics include the ability of the single element CID to quantitate photon fluxes ranging over eleven orders of magnitude, a quantum efficiency of the linear CCD in excess of 90%, and a read noise of the two-dimensional CCD of under 5 electrons. In addition, the use of the linear CCD for molecular fluorescence spectroscopy is demonstrated. A direct comparison of CCD and CID detection for atomic emission spectroscopy using a custom echelle system is described. The second part of these investigations focus on the design of spectrometers compatible with the format of these multichannel detectors. While a large number of spectrometer designs exist, the spectrometer and detector combination which produces the highest possible signal-to-noise ratio (SNR) spectra for a given experimental system is almost always desired. The investigations into optimum spectrometer design have led to the use of a unique spatial interferometer system. The performance of a common path interferometer using a linear charge-coupled device detectors is presented and compared to conventional dispersive systems. The throughput, resolution, and other practical factors are discussed. The common path system has a much larger light gathering ability compared to dispersive systems; however, spatial interferometry suffers from the multiplex disadvantages encountered with other forms of UV/Vis interferometry. A unique crossed interferometric dispersive arrangement allows the simultaneous acquisition of the spectral information while greatly reducing these multiplex disadvantages. Preliminary work on the crossed interferometric system is presented demonstrating significant reduction of these multiplex disadvantages.

A parametric design study of light weight mirror shapes with various support conditions was performed utilizing the finite element program NASTRAN. Improvements in the mirror performance were made based on the following design criteria: (1) minimization of the optical surface wavefront variations, (2) minimization of the self-weight directly related to cost of manufacturing, and (3) optimal location of support points. A pre-processor to automatically generate a finite element model for each mirror geometry was developed in order to obtain the structural deformations systematically. Additionally, a post-processor, which prepares an input data file for FRINGE (an optical computer code) was developed for generating the optical deflections that lead to the surface wavefront variations. Procedures and modeling techniques to achieve the optimum (the lightest and stiffest mirror shape due to self-weight) were addressed. Fundamental natural frequency analyses, for contoured back mirror shapes for a variety of support conditions, were performed and followed by comparisons of the results which were obtained from NASTRAN and a closed-form approximate solution. In addition, element validity and sensitivity studies were conducted to demonstrate the behavior of the element types provided in the NASTRAN program when used for optical applications. Scaling Laws for the evaluations of the optical performances and the fundamental frequencies were established.

Unobscured reflective optical systems can be more transmissive and of higher diffraction quality than classical systems. Unobscured systems are generated by decentering symmetric systems, tilting elements to correct coma or astigmatism along a real ray, or by cross-tilting elements to control astigmatism. Such a system of relatively high quality may be further corrected with a general spline surface. For spline surfaces, optical aberration coefficients are undefined. This study developed real ray analysis and design techniques for general optical systems. A decentered symmetric system with a field correcting spline surface was designed. The optical design program ACCOS V was used for most design and analysis tasks. Design and analysis of general systems are considered first. Basic system quantities of image location, scaling, and irradiation are defined with real rays. Spline surfaces are discussed with special emphasis on features important in optical design. Real ray analytical techniques of composite spot diagrams across the image, footprints on spline surfaces, wavefront aperture maps, and spline surface maps are described. The use of these tools in general system design procedures is discussed. Standard telescope objectives of f/8.5 were considered as base designs for systems with spline surfaces. A spline surface was added to the decentered Schmidt-Cassegrain. Optimization yielded diffraction-limited performance across a 0.85 degree square field. The spline system was compared to the Galileo spacecraft narrow angle lens and a three-mirror decentered design. It had a far wider field than the Galileo but at a lower quality. Diffraction quality was better than that of the three-mirror system. Simple tolerances were considered for the spline system. The allowable effect of a thermal gradient was estimated by bending the reference axis. Decentration and figure tolerances for the spline were commensurate with classical surfaces. Techniques presented were shown to be useful for design and analysis of general systems. Spline surfaces were found to be useful in optimization of such systems. This work was supported by the Director's Discretionary Fund, Jet Propulsion Laboratory, California Institute of Technology.

The primary distinction between an ordinary optical system and one which is both unobscured and reflective is that the elements of the latter must be tilted or decentered with respect to one another. In general, this results in an optical system which has no axis of rotational symmetry, and therefore the classical aberration theory of symmetric systems is no longer applicable. Furthermore, the image becomes anamorphic and keystone distorted, due to the relative tilt between the object and the optical surfaces. The first part of this work is the development of a semi-analytic treatment of the properties (through third order) of systems possessing large tilts and decentrations. The Gaussian properties of both the image and pupil are described in terms of tilt, decentration, magnification, keystone distortion, and anamorphic distortion parameters. In computing these parameters, it is important to take into account the transferred components of the parameters, which are due to the Gaussian properties of the preceding surfaces. The third order properties are computed using the fact that each optical surface, together with its associated entrance pupil, form an optical subsystem which possesses an axis of approximate symmetry. About this axis, the aberration contributions of that surface may be described in the classical wave aberration expansion. The coefficients in this expansion may be corrected for the non-circular appearance of both the object and pupil, using the parametric description of their Gaussian form. the aberration fields due to the various surface contributions are then combined vectorally to yield the resultant aberration field in the image plane. The vector theory is applied to the analysis of several optical systems, and the accuracy of the theory verified by comparison with raytrace data. As a demonstration of the usefulness of the theory to an optical designer, a three mirror unobscured system was designed using a methodology derived from the theory. At each step, the design options are explained, and the probable results are discussed. The residual aberrations of the resulting system are studied, and the selection of another design starting point is discussed from the point of view of the theory.

No description available.

The purpose of this investigation is to examine synthesis for reconstruction of electrostatic lenses having an axial potential distribution four times continuously differentiable. The solution of the electrode and pole piece reconstruction is given. Spline functions are used to approximate a continuous function to fit a curve. The present method of synthesis is based on cubic spline functions, which have only two simultaneous continuous derivatives, and all the other higher derivatives are ignored. The fifth-order or quintic spline is introduced simply because it has four simultaneous continuous derivatives. So the reconstruction program would have three terms appearing in the series expansion of the off-axis potential distribution, with regard to two terms when using cubic functions.

No description available.

The work of this thesis is to investigate new techniques for Integral Field Spectroscopy (IPS) to make the most efficient use of modem large telescopes. Most of the work described is aimed at the FMOS for the SUBARU 8m telescope. Although this is primarily a system for Multiple Object Spectroscopy (MOS) employing single fibres, there is an option to include a multiple-IFS (MIPS) system. Much of this thesis is therefore aimed at the design and prototyping of critical systems for both the IPS and MOS modes of this instrument. The basic theory of IFU design is discussed first. Some particular problems are described and their soludons presented. The design of the MIPS system is described together with the construction and testing of a prototype deployable IFU. The assembly of the pickoff/fore-optics, microlens array and fibre bundle and their testing are described in detail. The estimated performance of the complete module is presented together with suggestions for improving the system efficiency which is currently limited by the performance of the microlens array. The prototyping of the MIPS system is supported by an extensive programme of testing of candidate microlens arrays. Another critical aspect of the instrument is the ability to disconnect the (IPS and MOS) fibre input which is installed on a removable prime focus top-end ring from the spectrographs which are mounted elsewhere on the telescope. This requires high-performance multiple fibre connectors. The designs of connectors for the MOS and IPS modes are described. Results from the testing of a prototype for the MOS mode are presented. This work is supported by a mathematical model of the coupling efficiency which takes into account optical aberrations and alignment errors. The final critical aspect of FMOS which has been investigated is the design of the spectrographs. The baseline system operates in the near-infrared (NIR) but an additional visible channel is an option. Efficient designs for both the visible and NIR systems are presented. The design of the NIR spectrograph presents challenges in the choice of materials for the doublet and triplet lenses employed. The choice of material and the combinations in which they can be used are described. This thesis shows that all these critical aspects of FMOS have good solutions that will result in good performance of the whole instrument. For the multiple IFU system, the prototype demonstrates acceptable performance which can be made excellent by the use of a better microlens array. The multiple fibre connector prototype already indicates excellent performance. Finally, the spectrograph designs presented should result in high efficiency and good image quality.

The acoustic impedance is a valuable parameter in musical acoustics. Information contained within this frequency-domain parameter can be used to determine the acoustical behaviour of a musical wind instrument: the notes at which the instrument will play; the ease with which a particular note can be played; and the timbre of the instrument. The time-domain version of acoustic impedance - the input impulse response - gives us information on how sound waves propagate within an instrument under playing conditions and how sound is radiated from the open end or from other holes in the bore. Acoustic impedance data can also be used to calculate an accurate profile of the internal structure of the instrument - referred to as a bore reconstruction. This is very useful as the main bore is usually coiled and difficult to measure mechanically. An accurate reconstruction, however, is only possible if the impedance is measured over a large range of frequencies, typically of the order of tens of hertz up to many kilohertz. The bulk of this work follows on from research where the impedance of a short, closed, cylindrically-symmetric tube has been measured experimentally at high frequencies - 1 kHz up to 20 kHz - and compared with theory. The technique used is known as the Two-Microphone-Four-Calibration system, or TMFC system: two microphones are used to monitor the air pressure in the system, and measurement of four closed tubes of different length are required for calibration. The TMFC system has been modified so that impedance data far below 1 kHz (down to 10 Hz) can be attained for a full instrument as well as instrument components - for example trombone mouthpieces or French horn crooks. Suitable algorithms have been developed for processing the impedance data. Obtaining large bandwidth impedance data has allowed the possibility of accurate reconstructions of an instrument's internal profile. The results are compared with plane-wave theoretical models, which are derived in detail, and other well-documented methods of bore and impedance analysis: the acoustic pulse reflectometer (APR), and the brass instrument analysis system (BIAS). An in-depth discussion and analysis of the TMFC results for test objects and instruments of various lengths are presented. Simulations, whereby bore profiles are artificially altered, and a post-processing method utilising transmission matrix theory (TMT), are explored. A variety of orchestral French horn crooks dating from as early as the 18th-Century have been measured using APR and TMFC. A comparison is made between the capabilities of the two systems. Conclusions - of interest from a historical and manufacturing perspective - are drawn. The BIAS has been used to investigate how changes to the bore profile affect the behaviour of trumpets. The impedance of the trumpet is measured using a variety of leadpipes and mouthpieces.

Adolphe Sax developed in Paris in the early 1840s a family of brass instruments, the saxhorns, which gained an immediate popularity in France, Britain and other parts of the world. The originality of saxhorns was challenged at the time through long-lasting litigations, and is still questioned by many researchers. This thesis investigates the development of the saxhorn from an organological standpoint. Saxhorns are examined in comparison to instruments predating them by other makers, along with relevant archival material (patents, lawsuit minutes, daily press, publicity material etc.) so as to reveal whether the allegations against their originality were sound. It is noticed that idiosyncrasies of intellectual property law of the time facilitated a strong interaction between musical instrument makers particularly of France and Britain. Instruments examined are Adolphe Sax saxhorns, saxhorns by other contemporary makers, mainly French and British, but not exclusively, as well as a number of related instruments, made before and after the development of Sax’s saxhorns. The assertions of Sax’s rivals are not fully confirmed based on the analysis of instrument measurements. It is also argued that the saxotromba family, so far considered extinct, is in fact represented by two members in the saxhorn family, the alto and the baritone. A number of related instruments emerged around the middle of the nineteenth century in various wraps and with different names. These are compared to saxhorns and classified according to bore-profile properties. Only certain groups were distinct, whereas most were essentially saxhorns in different forms. Sax’s brasswind production as a whole is reviewed not only as an enumeration of his developments, but also to provide an assessment of the genuine innovation in his work.