Cheng-An Lin

When searching for landmines using vehicular-mounted sensors, it is important that the ground locations of the detected mines be accurately determined. This is useful for data association when one has multiple looks at a mine by a single sensor or if one uses multiple sensors. This knowledge is necessary for neutralizing the detected mines or at least marking them for avoidance. Factors that contribute to errors in geo-location include sensor error, inaccurate knowledge of the vehicle position and/or attitude, and incomplete knowledge about the terrain being searched. This paper addresses the problem of incomplete terrain knowledge and its effects on geo-location accuracy. It presents different techniques for modelling the terrain and reducing the geo-location errors. A variety of uneven surfaces have been simulated. Random noise has been added to the basic surfaces to simulate the terrain roughness. A terrain model is then derived based on measurements one could obtain from a coarse scan of the field of view using a ranging laser. Two types of sensors are considered for the landmine detection: Synthetic Aperture Forward-Looking Radar (SAFLR) and Camera Type Sensors such as Infrared (IR). Relationships between the terrain unevenness and resulting geo-location errors are presented. The geo-location errors are worse for the Camera Type Sensor, but they can be significant for SAFLR also. The results of this analysis demonstrate that there may be significant geo-location errors for situations where the terrain is not so smooth, e.g. off-road searches, and that the problem can be alleviated via better knowledge of the terrain. If the field of view is planar or almost planar, even coarse-range scanning can improve the geo-location accuracy. For more complex surfaces, finer scanning may be required (preliminary results on this topic were presented at the SPIE (International Society for Optical Engineering) Conference, Orlando, FL, April 2001 (G. Cook, S. Jakkidi, S. Kansal, C. Amazeen and K. Sherbondy, “Impact of uneven terrain on geo-locations errors for mines detected via vehicular mounted sensors”, in Proceedings of SPIE, 2001, pp. 594–605.)). The computed geo-location errors, and the conclusions drawn as to the effectiveness of the different models are presented in the paper.

I am pleased to welcome you to this timely and informative conference organized by The International Society for Optical Engineering (SPIE). As Conference Chair, I amvery pleased, but not at all surprised, by your interest and enthusiastic response: Over 300 participants are contributing over 210 technical papers to six topical conferences.

For many years, programs have focused on single optical fiber sensors for each measurement required on an engine. Sensor systems therefore required signal processing for each of these individual sensors. While this approach provided the best individual sensor for each measurement, the system cost and complexity suffered. BFGoodrich has begun a new program focused on developing an optical fiber engine sensor suite based on one single sensing mechanism to monitor the majority of the measurements on an engine. The sensors will be optically multiplexed to a single signal processing unit thereby reducing cost, weight and size for the overall system. This program is a joint effort among three BFGoodrich divisions: Aircraft Sensors Division (Rosemount Aerospace), Aircraft Integrated Systems Division and Engine Electrical Systems Division. The program is described and results to date on choosing and developing the single sensing mechanism are presented.

The mission and scope of the National Science Foundation (NSF) and lightwave technology will be very briefly discussed. The focus of the presentation will be directed toward changes in research support that are taking place and the opportunities we have for aiming our research to meet the challenges and needs that face the nation. In the USA it is very clear that defense oriented research is downsizing and is being redirected into economy driven aresas, such as manufacturing, business, and industry. For those researchers who are willing to move into these areas and find a niche, the rewards may be very great. Industrial research partners should also seize these opportunities to enhance their resources in an otherwise bleak future for industrial support of basic research in lightwave technology and many other reserach disciplines. These activities of bringing together industry and academia will have the value added benefit of providing increased job opportunities for students. An outline of some of these opportunities and incentives will be presented. On the international front, there has never been a better time for the encouragement of joint research and collaboration across borders. The economic potential for involvement in Eastern Europe and Asia are enormous. Agencies like ourselves are open to help support of visiting scientist/engineer exchange, international conferences and forums and support of innovative ideas to help further enhance economic developemnt of the world and hence the quality of life. The presence of the Russian delegation here at these SPIE meetings in in part the result of NSF support. Concomitant with these changes is a growing interest in education. Academia is gradually realizing that education includes training for students to acquire jobs and hence we complete the cycle of the importance of interacting with industry. At the NSF a major new initiative is being introduced in Optical Science and Engineering (OSE). This effort has been created as an outgrowth of the NRC study being conducted in parallel under the same name. OSE is based on the fact that optics is a very interdisciplinary area and special emphasis on the interface between the relevant areas is where the action is. Lightwave technology and the implementation of organic materials to optoelectronic applications is clearly an area which has tremendous potential for economic impact and it fits the criteria for the OSE initiative. It is also exciting, challenging, and personally rewarding. But organic materials have been promising for quite some time and some are getting impatient. To provide credibility to those who support this research (governement, idustry, etc.), we must turn our attention to ways in which we can accelerate the transition from the laboratory discovery to the consumer. In this way everyone will become a winner.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The finite-difference time-domain (FD-TD) numerical solver for Maxwell's equations is used to model problems in nonlinear optics. Since FD-TD makes no assumptions about pulse bandwidth or preferred direction of scattering, and can account for frequency-dependent material properties that vary on a submicron scale, it can provide optical design engineers with an unprecedented level of detailed field information, including pulse dynamics. This paper presents FD-TD computed results for a variety of passive and active optical microstructures.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

One-dimensional (1-D) photonic bandgap (PBG) structures remain one of the most practical ways of applying the PBG concepts to the solution of many urgent problems in laser physics and optical technologies. The sol-gel method is an inexpensive and flexible liquid phase processing technique that is suitable for the deposition of multilayer stacks. The multilayer stacks can be designed as 1-D PBG structures, such as distributed Bragg reflectors (DBR), or single and coupled microcavities, as reported in this work. Spin-coated TiO2 and SiO2 layers acted as the high and low refractive index materials, respectively. Each layer was heat-treated at a high temperature (~1000 degree(s)C) for a short period of time (~90 s) in order to increase the index contrast, while preserving relatively smooth interfaces between the consecutive layers. Ellipsometry, X-ray diffraction, micro-Raman spectroscopy, transmittance/reflectance spectroscopy, and atomic force microscopy were used to characterize both the individual layers and the whole structures. Strong PBG properties are demonstrated, with an omni-directional stop band for a 5.5-pair DBR ((lambda) equals 550 - 600 nm, gap to mid-gap ratio equals 7.6%) and sharp pass bands within the stop bands for the microcavities.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The research in the field of gradient-index optics provided at the Institute of Applied Optics is reviewed. In particular, achievements in Luneburgs lens theory, measurements of refractive index profiling of gradient index elements and technology of GRIN optics making using ion- exchange in glass during the thermodiffusion process are presented. The bibliography of this work was done.

Recent advances in optical devices, polymeric materials, and in the electronic MCM packaging and interconnect technologies could bring the cost of optical interconnect to a level affordable for module, board, and backplane level interconnect applications. Specifically, we discuss how the development in (1) vertical-cavity surface-emitting-laser devices, (2) multichip module packaging technologies, (3) optical polymers, and (4) adaptive interconnect can be applied to benefit optoelectronic packaging and interconnect. We show how these advancements will allow widely used planar processes and the already developed packaging technology in electronics to be applicable to optoelectronic packaging to reduce both recurring and nonrecurring engineering costs for this new technology insertion into computers and advanced electronic systems.

A smart structure based on fiber optic sensor technology is used to provide nondestructive evaluation of fluids. Acoustic Resonance Spectroscopy techniques are used to extract fluid signatures using the proposed smart structure. These signatures are then presented to a nonparametric classifier either in their raw format or in a processed format based on autoregressive modeling techniques. Three types of nonparametric fluid classifiers are examined in this study. The performances of these classifiers are compared and the effects of autoregressive modelling on the classification performance are examined.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Ultra-high-speed optical communication networks will require routing switches which support data rates beyond the capabilities of optical-electronic conversion. This paper describes the preliminary design of an `all-optical' routing switch for a network in which data messages remain in optical form throughout the transmission from source to destination. The basic switch architecture and fundamental design trade-offs affecting switch implementation are discussed. Characteristics of the optical device technology required to implement the routing switch elements are also presented.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The report considers the evaluation of the automatic optical authentication technologies for the automated integrated system of physical protection, control and accounting of nuclear materials at RFNC-VNIITF, and for providing of the nuclear materials nonproliferation regime. The report presents the nuclear object authentication objectives and strategies, the methodology of the automatic optical authentication and results of the development of pattern recognition techniques carried out under the ISTC project #772 with the purpose of identification of unique features of surface structure of a controlled object and effects of its random treatment. The current decision of following functional control tasks is described in the report: confirmation of the item authenticity (proof of the absence of its substitution by an item of similar shape), control over unforeseen change of item state, control over unauthorized access to the item. The most important distinctive feature of all techniques is not comprehensive description of some properties of controlled item, but unique identification of item using minimum necessary set of parameters, properly comprising identification attribute of the item. The main emphasis in the technical approach is made on the development of rather simple technological methods for the first time intended for use in the systems of physical protection, control and accounting of nuclear materials. The developed authentication devices and system are described.

A new optical interference filter deposition technology demonstrated that provides the deep blocking and extended transmission regions required for multiphoton fluorescence applications. This technology allows for the deposition of high phase thickness coatings with many more layers than was previously possible. Theoretical blocking at a level greater than optical density 9 is achieved. We present examples of shortpass edge filters and bandpass filters with high transmission and deep blocking. A dichroic mirror with high reflection in the near infrared and an extended region of high transmission throughout the visible is also presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Holographic gratings of various kinds used as parts of optical layouts have received increasing attention in optical science and technology. It is a proposal to use a holographic grating in order to change the state of polarization of polarized light, what is the contribution dealing with. The subject follows our previous work. The treatment of that process is given. Attention had been paid to the properties of both amplitude and phase holographic grating. A possibility to use such a layout is discussed.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Recent developments in Er-doped glass waveguide amplifiers on silicon will be reviewed. In a number of devices usable gain at practical pump powers was demonstrated in packaged devices. Challenges of integration of waveguide amplifier devices into silicon optical bench technology will be discussed.

A great number of parallel computer architectures have been proposed, whether they are SIMD machines (Single Instruction Multiple Data) with lots of quite simple processors, or MIMD machines (Multiple Instruction Multiple Data) containing few, but powerful processors. Each one claims to offer some kind of an optimality at the hardware level. But implementing parallel image processing algorithms to make them run in real time will remain a real challenge; it addresses rather the control of communication networks between processors (message passing, circuit switching..) or the computing model (e.g. data parallel model). In that respect, our goal here is to point out some algorithmic needs to distribute image processing operators. They will be translated first in terms of programming models, more general then image processing applications, and then as hardware properties of the processor network. In that way, we do not design yet another parallel machine dedicated to image processing, but a more general parallel architecture which one will be able to efficiently implement different kinds of programming models.