This PDF file contains the front matter associated with SPIE Proceedings Volume 8127, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Optical design usually concentrates on local ray slopes, leaving local wavefront curvatures transformation as a side issue. In this presentation we develop a generalized ray tracing method for diffractive and refractive surfaces based on calculation of local wavefront curvatures. We showed that a non-paraxial wavefront transformation still can locally be described by the thin optical element model and developed relevant generalization of the Coddington equations. Ray tracing and diffraction through sequentially cascaded smooth optical surfaces with nonsymmetrical diffractive phase functions, can now be approached with nearly the same simplicity as customary in paraxial optics of thin lenses and Fourier optics. Relations between diffractive polynomial and fabricated microrelief profile are derived for scalar and resonance domain diffractive optics.

Reverse optimization is a means of determining the internal details of a system and can identify the internal root causes of the effects to provide the exact prescription ready for immediate implementation in system improvement. We can apply the reverse optimization method to complex physical optics systems including full diffraction at all steps, laser gain, nonlinear optics, resonant oscillations, etc. using damped least squares (DLS) optimization. The targets for DLS optimization may consist of specific performance measures and wavefront or irradiance maps that may consist of many millions of points readily obtained from beam diagnostic instruments. Reformulation of the DLS mathematics allows efficient calculation and some examples illustrate the method. The classical Jacobian matrix is no longer constructed directly saving computer memory and time. Instead a system matrix of small rank is built on the fly with data points accessed the minimum number of times.

Q-switch lasers are traditionally modeled using the rate equation approximation[1]. This model is effective in relating the energy of the population inversion to the energy in the optical pulse. It is especially effective when augmented by the Frantz-Nodvik theory that effectively builds in conservation of energy. However, the rate equation approximation theory cannot independently describe the formation of longitudinal modes and, because it does not correctly consider the finite response time of the medium, its accuracy in predicting the very fast rise time of Q-switch pulses is suspect. A more powerful based on the laser gain in terms of radiating, resonant dipoles-the coherent gain model-is needed. This paper reports progress to incorporate the more advanced coherent gain into a 3D, time resolved numerical model that can predict both sub-nanosecond effects, the growth of longitudinal modes in the Q-switched laser, and other coherent effects. Work remains to be done to explore the capabilities of this model to its full range of possibilities. Sandia National Laboratories has been interested in short pulse modeling and provided support for the development of the coherent gain model which is now being applied to the NASA Q-switch program to address fast rise times and the formation of longitudinal modes[2]-[6].

This paper presents an equivalent direct detection receiver model by statistical method which simplifies the random impulse responses of electrons counting of returned signal, background radiation and dark current as a Gaussian random process with high enough gain. An investigation based on Gaussian distribution of system output in ICCD scannerless range-gated Lidar system is conducted with the calculations of error probability, absolute error and relative error. As the unique manipulated variable, optimized system gains are calculated separately based on the Gaussian model of the random process to achieve the lowest error probability, the lowest absolute error and relative error. The simulations show that the values of optimized gains tend to increase along with the target distance, although the increasing speeds are different. To meet multiple requests, an evaluation model based on cost function is constructed with different weights. The simulation shows that the evaluation model is capable of setting optimized gains for different circumstances and the settings of the weights are vital to the performance of Lidar system.

We propose a new phase retrieval technique using a windowed Fourier transform (WFT) method for fringe pattern analysis to obtain a high-resolution phase map. The WFT method has been studied to improve the noise robustness of FT methods. In our proposed technique, an extra step is added to isolate the WFT spectrum containing phase information from other spectra, which is effective when a narrow window function is used for the high-resolution phase map. We demonstrate phase retrieval along both x- and y-axes from a two-dimensional fringe pattern obtained by X-ray Talbot imaging. Differential phase maps in high resolution with effective noise reduction are retrieved by the proposed method.

In last years paper on the idea of Lambertian reflection we gave a partial translation of an almost lost chapter by Lambert on multiple reflection as a gimmick. The problem of multiple reflections is of special interest in scatterometric devices. The present paper is dedicated to a deeper discussion of the model proposed by J.H. Lambert or, better to say, a derivation using the matrix method of paraxial optics. Further some examples and special cases - especially the consequences for scatterometer design - are discussed. For easy handling it would be desirable to derive some simplified formulas describing the effective higher order refraction qualities of thick lenses, which might support the choice of lenses for certain applications.

The present paper is understood as a continuation of our paper on the utilization of the Scheimpflug-principle in scatterometric devices. Imaging scatterometers in principle gather the fourier image of the illuminated spot, which in microscopy would be the primary diffraction image. Therefore imaging scatterometers can be used as microscopes as well, which only requires an additional positive lens or equivalent mirror. It is obvious that combined designs are interesting in surface inspection: because of the loss of phase information in both direct and scatter image, there is still non redundant information besides the intersection set of both images. For the design of such combined devices it is of high interest to identify the fourier images. While a more or less paraxial dioptric device in orthogonal view has well defined fourier planes, in an off axis device with paraboloid or elliptical mirrors the fourier image is concerned by the Scheimpflug relations, which shall be subject of the present paper.

This paper provides an overview of the various image quality metrics used in astronomical imaging and explains in details a new metric, the Normalized Point Source Sensitivity. It is based on the Equivalent Noise Area concept, an extension of the EE80% metric and is intuitively linked to the required science integration time. As it was proved in recent studies, the PSSN metric properly accounts for image degradation due to the spatial frequency content of a given telescope aberration and the effects of various errors can be multiplicatively combined, like those expressed in Central Intensity Ratio. Extensions of the metric for off-axis imaging and throughput degradation are presented. Wavelength and spatial frequency dependence of PSSN are discussed. While the proper calculation of the PSSN metric requires the precise knowledge of the PSF of both the optics and atmosphere, there is a straightforward approximation linking PSSN to the Zernike decomposition of the OPD. Besides the summary of various aspects of the Point Source Sensitivity, the paper provides many numerical examples derived for the Thirty Meter Telescope.

The Comet Performance Engineering Workspace is an environment that enables integrated, multidisciplinary modeling and design/simulation process automation. One of the many multi-disciplinary applications of the Comet Workspace is for the integrated Structural, Thermal, Optical Performance (STOP) analysis of complex, multi-disciplinary space systems containing Electro-Optical (EO) sensors such as those which are designed and developed by and for NASA and the Department of Defense. The Comet^TM software is currently able to integrate performance simulation data and processes from a wide range of 3-D CAD and analysis software programs including CODE V^TM from Optical Research Associates and SigFit^TM from Sigmadyne Inc. which are used to simulate the optics performance of EO sensor systems in space-borne applications. Over the past year, Comet Solutions has been working with MZA Associates of Albuquerque, NM, under a contract with the Air Force Research Laboratories. This funded effort is a "risk reduction effort", to help determine whether the combination of Comet and WaveTrain^TM, a wave optics systems engineering analysis environment developed and maintained by MZA Associates and used by the Air Force Research Laboratory, will result in an effective Model-Based Engineering (MBE) environment for the analysis and design of laser weapons systems. This paper will review the results of this effort and future steps.

The Cassegrain telescope system was design for space environment. The correct lens mount assembly is included as correct lens, lens mount, spacer, mount barrel and retainer. The system mass budget allocated to correct lens assembly was 5 Kg. Meanwhile, according to optical design the correct lens is made from fused silica, the lens diameter is 130 mm, and the mass is 2.3 Kg. Therefore, remain mass budget is 2.7 Kg; including the lens mount, spacer, mount barrel and retainer. The telescope system deformation is mainly caused by thermal deformation on space orbit. The correct lens mount was made from invar material in initial design. The CTE (Coefficient of Thermal Expansion) of invar is only 1* 10^-6/°C, low CTE would be resistant to thermal deformation, but invar density is 8* 10^-6 kg/mm³. If all components were made from invar, the total mass was over 2.7 kg. Thus, the components material would consider titanium alloy (CTE is 8.6* 10^-6/°C, density is 4.43* 10^-6 kg/mm³) or aluminum alloy (CTE is 23.6* 10^-6/°C, density is 2.81* 10^-6 kg/mm³). The titanium alloy density is 1.83 times lighter than invar, but CTE is 8.6 times higher. The aluminum alloy density is 2.84 times lighter then invar, but CTE is 23.6 times higher. The lens mount thermal deformation would effect correct lens surface wavefront error and introduce optical aberration. This article analyzes the correct lens assembly thermal deformation and optical performance in different lens mount material. From above conditions, using FEM (Finite Element Method) and optical software, simulation and optimization on the lens mount design have been performed to achieve system mass requirement.

The Navy Prototype Optical Interferometer (NPOI) array, located near Flagstaff, Arizona, transports 12.5 cm diameter stellar radiation simultaneously from six primary collectors through a 9,000 cubic foot vacuum relay system prior to entering a specialized laboratory where further manipulations of each beam occur. The relay system redirects each 12.5 cm beam 10 times. Ground-based optical interferometry requires very high quality, ideally flat, relay mirrors. The mirrors used in the relay system have flatness deviation tolerance 32 nm peak-to-valley over the 18.3 cm clear aperture. Once mounted in the 10-element optical train, errors from each mirror tend to stack up and increase the resultant wavefront distortion for that path. This leads to reduced fringe contrast, fringe tracking, and number of observables. In a previous paper, it was shown that it is possible to mitigate the resultant wavefront distortion by using a phase-shifting interferometer combined with a single compliant static deformable mirror and control system. In that work, the mirrors tested showed a fairly uniform, concentric concavity deformation, which a single, centrally located actuator may significantly improve. In this paper, we extend the previous analysis to consider an off-center actuator acting on a mirror to counteract an asymmetric wavefront distortion resulting from the superposition of several relay mirrors. The shape applied to a single corrector mirror was determined from the resultant wavefront distortion of a 7-reflection optical relay system using phase-shifting interferometer data. Finite element analysis results indicating how resultant wavefront error from a collection of slightly deformed mirrors can be cancelled are presented and discussed.

BigBOSS is a proposed DOE-NSF Stage IV ground-based dark energy experiment designed to study baryon acoustic oscillations (BAO) and the growth of large scale structure with a 14,000 square degree survey of the redshifts of galaxies and quasi-stellar objects. The project involves modification of existing facilities operated by the National Optical Astronomy Observatory (NOAO). Design and systems engineering of a preliminary 3 degree field of view refractive corrector, atmospheric dispersion corrector (ADC), and 5000 actuator fiber positioning system are presented.

The effect of the acceleration force during launch on the primary mirror of a Cassegrain telescope has been studied in the paper. Finite element method and Zernike polynomial fitting are applied to the ZERODUR^R primary mirror with a predesigned lightweight configuration on the back. The relations between several selected surface treatment conditions and the mirror characteristic strength as well as the safety factors under various launch accelerations have been investigated. It is found that the surface treatment on the mirror surface needs to be at least ground using a D251 or finer tool to keep the load safety factor of the primary mirror structure of the telescope higher than 1.5 aerially. In addition the principle strss difference of the lightweight ZERODUR^R mirror induced by the grinding process with an average grain size of 149 μm is up to 1 MPa.

An earth-based ground terminal and a lunar orbiting space terminal are being developed as part of NASA's Lunar Laser Communications Demonstration program. The space terminal is designed to minimize mass and power requirements while delivering high data rates using a four-inch aperture telescope and a 0.5 watt beam. Design challenges for the space terminal include providing telescope pointing stability to 4 μrad RMS and diffraction-limited wavefront quality. Conflicting design requirements including stress, LOS jitter, mounting errors, and thermal distortion were balanced to meet performance requirements in the presence of operational vibration and thermal disturbances while assuring that the system will survive the launch load environment. Analysis techniques including finite element analyses, closed-loop LOS jitter simulations, and integrated optomechanical analyses were utilized to evaluate and drive proposed design solutions to the final telescope configuration.

Space borne astronomical telescopes are subjected to random dynamic disturbances from the host spacecraft that create line-of-sight (LoS) jitter errors, which decrease image quality. Special software tools and techniques have been developed to determine the degradation in image quality as measured by the modulation transfer function (MTF) and to identify regions of the telescope to be redesigned in order to minimize the LoS jitter response. A general purpose finite element program is used to find the natural frequencies and mode shapes of the telescope. Each of the optical surfaces for each mode shape is then decomposed into average rigid body motion and elastic deformation. Automated calculation of the LoS equations based on the optical prescription of the telescope provides the LoS response due to expected random loads. The percent contribution of each mode shape to the total LoS jitter is reported that helps pinpoint regions of the telescope structure to redesign. The LoS error due to the random input is then decomposed into drift and jitter components based on a specified sensor integration time. The random jitter is converted to a jitter MTF response function which may be used to modify the MTF function of the nominal optical system yielding the resulting optical system MTF in the operational random environment.

Point spread function (PSF) models are critical to Hubble Space Telescope (HST) data analysis. Astronomers unfamiliar with optical simulation techniques need access to PSF models that properly match the conditions of their observations, so any HST modeling software needs to be both easy-to-use and have detailed information on the telescope and instruments. The Tiny Tim PSF simulation software package has been the standard HST modeling software since its release in early 1992. We discuss the evolution of Tiny Tim over the years as new instruments and optical properties have been incorporated. We also demonstrate how Tiny Tim PSF models have been used for HST data analysis. Tiny Tim is freely available from tinytim.stsci.edu.

The performance metrics of many optical systems are affected by temperature changes in the system through different physical phenomena. Temperature changes cause materials to expand and contract causing deformations of optical components. The resulting stress states in transmissive optics can cause refractive changes that can affect optical performance. In addition, the temperature changes themselves can cause changes in the refractive properties of transmissive optics. Complex distributions of refractive indices that relate to the thermal profile, the thermo-optic refractive index profile, within the optical media can be predicted by the finite element method. One current technique for representing such refractive index profiles is through the generation of OPD maps by integration along integration paths. While computationally efficient, this method has limitations in its ability to represent the effect of the index changes for rays associated with multiple field points and multiple wavelengths. A more complete representation of the thermo-optic refractive index profile may be passed to the optical analysis software through the use of a user defined gradient index material. The interface consists of a dynamic link library (DLL) which supplies indices of refraction to a user defined gradient index lens as ray tracing calculations are being performed. The DLL obtains its refractive index description from a database derived from the thermal analysis of the optics. This process allows optical analysis software to perform accurate ray tracing for an arbitrary refractive index profile induced by changes in temperature. The implementation of this method by the authors is currently in development as a feature in Sigmadyne/SigFit, and this paper is a current status of that effort.

A concurrent engineering approach to the design and analysis of a space-borne Electro-Optical (EO) sensor is presented. A detailed design of an infrared telescope payload is developed by an interdisciplinary team of mechanical, structural, thermal, and optical engineers using a Simulation Driven Engineering (SDE) software environment. The telescope payload design is also integrated with a conceptual level design of the space segment of a mission that incorporates the payload. The flow of the concurrent design process is described, and design outputs are provided.

The efficient simulation of multidisciplinary thermo-opto-mechanical effects in precision deployable systems has for years been limited by numerical toolsets that do not necessarily share the same finite element basis, level of mesh discretization, data formats, or compute platforms. Cielo, a general purpose integrated modeling tool funded by the Jet Propulsion Laboratory and the Exoplanet Exploration Program, addresses shortcomings in the current state of the art via features that enable the use of a single, common model for thermal, structural and optical aberration analysis, producing results of greater accuracy, without the need for results interpolation or mapping. This paper will highlight some of these advances, and will demonstrate them within the context of detailed external occulter analyses, focusing on in-plane deformations of the petal edges for both steady-state and transient conditions, with subsequent optical performance metrics including intensity distributions at the pupil and image plane.