Introduction

OSLO is an acronym that stands for Optics Software for Layout and Optimization. The current OSLO programs are the latest in a series of optical design programs whose genesis is a program developed for teaching optical design at the University of Rochester. In addition to features that take advantage of changes in optical design and computer technology, OSLO now includes many features formerly available in the GENII program, which Sinclair Optics acquired from Genesee Optics Software in 1993. Moreover, OSLO is now available in three versions, OSLO SIX, OSLO PRO, and OSLO Light (or OSLO LT) to meet the general requirements of three user disciplines: advanced research and development, professional optical design, and general optical engineering.

The division of OSLO into three programs has been done to extend its range of applicability, and to provide economical access to the program by eliminating advanced features from the simpler versions. For internal program development at Sinclair Optics, there is only one program. The different versions are obtained by means of compiler directives from the same source code. This scheme ensures that all users will have access to the highest level of software quality. Since the small versions are subsets of the main program, they are compatible. Lenses saved in one version can be read by a higher-level version.

There is a tremendous range of scale and complexity in optical design projects. A simple imaging system may have a half dozen surfaces, and can be quite adequately designed, using an error function built from a half dozen rays in a single color, in a few seconds. On the other hand, a precision microlithography system or a TV zoom lens may have dozens of surfaces and several zoom configurations, requiring an error function with hundreds of rays in a dozen colors, and may take hours for a single design iteration.

OSLO SIX is the flagship version of OSLO. It is intended for advanced research and development work. In addition to the lens design and evaluation features of OSLO PRO and OSLO Light, it contains several features that provide forefront design capability, such as

OSLO PRO is an advanced optical design program that adds a highly-efficient operands compiler to the evaluation and basic optimization features of OSLO Light. OSLO PRO is ideally suited for optical designers who place heavy loads on the optimization portions of their software. OSLO PRO includes

OSLO Light makes use of the unique capabilities of OSLO to provide an economical program that is simultaneously easy to use and unusually powerful. In particular, OSLO Light includes a macro language called SCP that has complete access to the hundreds of commands contained in the program. This language is used in OSLO Light not only to extend the capabilities of the program, but to build error functions for optimization and tolerancing. In addition to default routines that set up common design tasks, the program gives the user complete flexibility in solving special problems. OSLO Light was formerly named OSLO Analyst, and before that, OSLO MG.

OSLO LT has the same features as OSLO Light, but file saving is not supported, hard copy output is by screen capture only, and input is restricted to spreadsheets or supplied demo files.

This User’s Guide constitutes the principal documentation for OSLO Light and LT, and serves as an introductory guide for OSLO PRO and OSLO SIX. Two other volumes, the Program Reference Manual and the Optics Reference Manual, are specifically intended for use with OSLO PRO and OSLO SIX (although much of the material is also relevant to OSLO Light and LT). A separate addendum to the Program Rerference describes features added in Rev. 5.2. The general content of the manuals is as follows.

User’s Guide	Summary of general program operation with cookbook instructions for simple systems and several example lenses.
Program Reference (including Rev. 5.2 addendum)	Description of how to use OSLO, organized according to the default menu commands, with summary descriptions of commands and macro programming at the end.
Optics Reference	Background information of the theory and algorithms used in OSLO, together with examples of typical use, organized according to optical tasks to be performed.

The official documentation for all versions of OSLO is the on-line help system, specifically the Commands reference volume, which is, in fact, the source code for the command definitions that are used to build the program. This information is best referenced through the context-sensitive help files coupled to the individual spreadsheets and dialog boxes in the program.

OSLO documentation assumes that you have at least an introductory background in optical design. Naturally, the experience required depends on the type and complexity of the task to be accomplished. Because of its background as a teaching program, OSLO is easy to use for simple designs. At the same time, some of the tools in the program require you to have a solid knowledge of optical principles to achieve successful results. The primary emphasis in the manuals that accompany the program is to explain how to use the program, the input data required, and the meaning of the output data. It is expected that you will consult the optics literature when necessary.

There are now quite a few good books on optical design, although curiously there are not so many available on computer-aided optical design. The following is a short list of titles that are especially recommended for OSLO users.

Warren J. Smith, "Modern Optical Engineering (Second Edition)", McGraw-Hill 1990, ISBN 0-07-059174-1. Also "Modern Lens Design", co-authored with Genesee Optics Software (now Sinclair Optics), McGraw-Hill 1992, ISBN 0-07-059178-4. The first of these has been the standard reference in optical engineering since its first edition was published thirty years ago. If you are able to have only one book on optical engineering, this is the one to have. The second book is more specific to lens design and is supplied with OSLO PRO and SIX. It describes the lenses contained in the public\len\lib\wsmith directory. It is one of the few places where computer optimization is discussed. Both books are used in Warren Smith’s Modern Lens Design courses.

Robert R. Shannon, "The Art and Science of Optical Design", Cambridge University Press 1997, ISBN 0-521-58868-5. This is a new book that surveys the overall design of image-forming systems, including elementary theory and several examples that show the use of three contemporary optical design programs (one of which is OSLO). The book is an outgrowth of lens design classes taught by the author at the Optical Sciences Center, University of Arizona.

W.T. Welford, "Aberrations of Optical Systems", Adam Hilger 1986, ISBN 0-85274-564-8. This is a more formal description of the theory underlying many of the algorithms used in OSLO. For many years this book was used as a text in the first-year graduate course in geometrical optics at The Institute of Optics, University of Rochester.

A. Walther, "The Ray and Wave Theory of Lenses", Cambridge University Press 1995, ISBN 0-521-45. This is the way geometrical optics should be taught (unfortunately it is not). The book is highly recommended to all who really want to understand how their designs work. While the narrative assumes a level of mathematical competence that will strain the abilities of many optical designers, the author’s felicitous style and penchant for compartmentalization make it quite readable.

Max Born and Emil Wolf, "Principles of Optics", Pergamon Press, ISBN 0-08-018018 3. This is the standard reference for classical optics. It should be a part of every optics library. Although it does not deal with computer algorithms or numerical analysis, it covers most of the optical principles used in OSLO.