This paper deals with the predesign of a two-element objective for the infrared spectrum. The design procedure is based on Warren Smith's MOE (Modern Optical Engineering), Third Edition, and illustrates the wealth of information and practical guidance that is available in this classic work. We find the choice of the basic configuration and follow the procedure for minimizing the aberrations through lens-bending, aspherizing, and the use of a diffractive surface. All this is achieved without the use of a computer. The results will then be applied to quickly computer-optimize the system after adding a proper thickness to the elements and a reasonable field of view.
This paper contains some recommendations for the optics curricula that seek to serve students intent on a career in optical engineering, as well as suggestions for the young professional embarking on such a career. It also illustrates the suggestions with some examples of actual optical systems.
This paper is an eclectic compilation of designs, ideas, observations, and lessons learned over the twenty-six year career of an optical design engineer. And, un-be-knownst to Warren Smith, he has played a significant and influential roll in this career, as I am certain he has in many others. More often than not, when one thinks of influential people in their careers, names will surface for which there are tight bonds, friendship, or a long history of contact etc. But how often do we name those whom we have never met, or at best, know casually through contact at professional conferences? I believe that Warren Smith holds the unique position of having influenced the careers of thousands of people, while simultaneously having knowledge of a very small fraction of them. I am confident that Warren is unaware of most of the lives he has touched and changed for the better. How many times have YOU reached for your copy of 'Modern Optical Engineering', or gone running through the halls, searching for someone else's copy that you can quickly borrow? By the way, I have one observation/question that I keep asking myself. Warren Smith initially wrote Modern Optical Engineering like, back in the 1920's or something. My question is 'How can it still be considered MODERN optical engineering?' Shouldn't it be 'Sunset' optical engineering, or 'Relatively Old' optical engineering or something? Also, it seems that all Warren basically did, is publish to existing stuff. Just about everything in his book was already known in the field of optics. All he did was to compile existing information, arrange it in a coherent form, add some words and pictures, and publish. Well HECK! I figured that I could do THAT! So I Xeroxed the pages of MOE and brought them to the SPIE publisher and said that I had a book on optical engineering that I'd like to publish. They seemed very interested. When I showed them the pages of my 'first draft', they quickly showed me the way out. I still don't get it. How come Warren gets away with it but I don't?
Brought on by the availability of large computers and optimizations programs, zoom lens design has advanced continuously during the past forty years. Changes in applications, manufacturing, and requirements have all contributed to a large and growing knowledge of zoom lens design. As a result entirely new zoom lens forms have been developed for use in a variety of cameraas and instruments. Most of the new designs are characterized by complex motions of zooming groups, and particularly by moving the aperture stop during zooming. Continuing to find ways to control the internal pupil imaging, the compound zoom lens has been developed. By performing the zooming operation on both sides of an intermediate image, the pupils and images are located advantageously.
This paper will be a survey of some designs I did about 30 years ago,
where all the surfaces are monocentric or are monocentric with some added flat surfaces. This would seem like a severe design constraint, to have all the surfaces have the same center of curvature, but a surprising number of interesting and useful designs can be done despite that. They are all either catadioptric or all-reflective and range from the very simple to the rather complex. I will first look at designs that are exactly monocentric, and then move on to designs that also have some flat surfaces. In monocentric designs with the stop at the center of curvature and a monocentric image surface, the performance is the same for any field angle.
In the period from 1973 through 1992, Polaroid introduced six different free-form aspheric optical surfaces in some unusually innovative instant photographic cameras, made in the millions. In each case these peculiar components were used to solve unusual problems of product size, shape, and function. This presentation relates how and why those surfaces were used and how they were tooled and manufactured with high quality.
A set of 200 Tessar lenses, covering a wide range of f/ numbers and angular fields, was designed with a consistent optimization scheme. Four different high-index crown glasses were used for the front and back elements, while the glasses of the remaining two elements were optimization variables. The imaging quality and trends in the index and dispersion of the variable glasses were analyzed and described.
The influence of diffractive optics on modern optical engineering has been considerable. The paper discusses a wide variety of applications of diffractive surfaces in the infrared and visible wavebands. Successful developments in low mass and multi-waveband infrared optics are described and results presented from manufactured hardware. The use in the visible waveband for real-time 3-D imagery, high power magnification of full colour displays, and possible use in diffractive-only helmet displays are examined for their potential. The limitation in the use of conventional diffractive surfaces for wide spectral bandwidth applications is described along with a method for alleviating this problem.
The Spaceborne Infrared Atmospheric Sounder for Geosynchronous Earth Orbit (SIRAS-G) is an infrared imaging spectrometer concept being developed to address future Earth observation from both low-earth and geosynchronous orbit. SIRAS-G is now in its second year of development as part of NASA's Instrument Incubator Program. The SIRAS-G approach offers lower mass and power requirements than heritage instruments while offering enhanced capabilities for measuring atmospheric temperature, water vapor, and trace gas column abundances at improved spatial resolution. The system employs a wide field-of-view hyperspectral infrared optical system that splits the incoming radiation to several grating spectrometer channels. Combined with large 2-D focal planes, this system provides for simultaneous spectral and high-resolution spatial imaging. In 1999, the SIRAS team built and tested the SIRAS LWIR spectrometer also under NASA's Instrument Incubator Program (IIP-1). SIRAS-G builds on this experience with a goal of producing a laboratory demonstration instrument operating in the MWIR including the telescope, a single spectrometer channel, focal plane and active cooling subsystem. In this paper, we describe the on-going development of this instrument concept, focusing on aspects of the optical design, fabrication and testing of the demonstration instrument, performance requirement predictions and potential future scientific instrument applications.
Deep Impact is NASA's Discovery class mission to Comet Tempel 1. The probe will separate into two spacecraft, one of which will impact the surface and excavate a large crater. Optical observations will allow the mission to determine much about the composition and structure of the comet nucleus, of which very little is known, in addition to helping the craft navigate to the target. We will discuss the mission, its goals and hardware, with emphasis on the optical instruments and the challenges of designing passive cryogenic optics for deep space operation while staying within tighter cost constraints than have been the norm for space missions.
When looking into even modern textbooks on optical design and engineering one can get the impression that everything has already been said about microscope optics. Also at optical conferences microscope optics is at most a marginal topic. Because of this only insiders are aware about the exciting challenges and really amazing achievements in today's state-of-the-art microscope optics. To give an example, this paper will focus on ultra-high resolution DUV microscope objectives for semiconductor inspection and metrology with feature size (half pitch) resolution down to about 60 nm. To meet the performance requirements of such objectives all aspects of optical design and tolerancing, optical coating design, optical production, assembly and image performance assessment have to be matched perfectly to each other at the highest technological level.
Splitting an optical system into two parts separated by an intermediate image is a very fruitful method for designing ultra-wide-angle, ultra-large-aperture lenses. This technique is illustrated by several designs having an extremely large optical invariant. These designs are further characterized by low geometrical distortion and remarkably uniform relative illumination.
The title of my paper refers to "very high power densities", and this implies here, of course, optical power, but first I should quantify what I mean by "very high". For the purpose of this paper, it shall mean power densities at and beyond which optical glasses are no longer transparent. This occurs basically due to the creation of free electrons by multi-photon absorption, which then cause stress and subsequent physical damage, such as cracks, in the glass. There is a threshold for this phenomenon, typically of the order of 1010 W/cm2 but strongly material dependent. For comparison: this is 7 orders of magnitude higher than what we can ever achieve by focussing light from the sun, our most powerful natural radiation source. It is, needless to say, readily achieved with current technology solid state pulsed lasers.
We review how optical aberration correction principles were applied in the design of classical photographic lenses. This makes the teaching of lens design more meaningful and interesting since a logical approach to understanding the increasing complexity of objective lenses is used.
Precision polymer optics, manufactured by injection molding techniques, has been a key enabling technology for several decades now. The technology, which can be thought of as a subset of the wider field of precision optics manufacturing, was pioneered in the United States by companies such as Eastman Kodak, US Precision Lens, and Polaroid. In addition to suppliers in the U.S. there are several companies worldwide that design and manufacture precision polymer optics, for example Philips High Tech Plastics in Europe and Fujinon in Japan. Designers who are considering using polymer optics need a fundamental understanding of exactly how the optics are created. This paper will survey the technology and processes that are employed in the successful implementation of a polymer optic solution from a manufacturer's perspective. Special emphasis will be paid to the unique relationship between the molds and the optics that they produce. We will discuss the key elements of production: molding resins, molds and molding equipment, and metrology. Finally we will offer a case study to illustrate just how the optics designer carries a design concept through to production. The underlying theme throughout the discussion of polymer optics is the need for the design team to work closely with an experienced polymer optics manufacturer with a solid track record of success in molded optics. As will be seen shortly, the complex interaction between thermoplastics, molds, and molding machines dictates the need for working closely with a supplier who has the critical knowledge needed to manage all aspects of the program.