Often the best way to learn how to do something in a new program is to see how a similar task was performed using the program. Accordingly, this chapter consists of a number of systems that make use of one or more of the basic features of OSLO. Some have been described in detail in the previous text, others are presented here for the first time. Some are included to serve as base designs that you can use to develop enhanced systems; others are included only for their tutorial value.
Each example corresponds to a file in the public\len\demo\usrguide directory in OSLO (but not all files there are described here). All of the examples here can be run in any version of OSLO; those that require OSLO PRO or OSLO SIX are contained in the public\len\demo\pro or public\len\demo\six directories. Each example contains a listing, drawing, and some comments on the system. In this chapter no attempt is made to provide cookbook instruction on how to evaluate or modify the system. For that, please consult the previous chapters.
For most examples, you should be able to get a good idea of the purpose by reading the description here and experimenting with the file using the toolbar icons and menus. If you have trouble understanding something, try tracing a few single rays through the system, or making a change to the system and seeing its effect. If you really want to see the details, you can open the file in the text editor.
Aside from the perfect lens, which is included because many people are confused about the difference between a perfect lens and a "paraxial" lens, all of the systems here are more complicated than singlets and cemented doublets. Although much good knowledge of optical design can be learned from studying singlets and doublets, there are literally thousands of such lenses in the OSLO catalog database, which you can browse through and experiment with as appropriate.
Anamorph shows the use of cylindrical lenses, special apertures, and the pickup-length-minus (pkp lnm) command that holds the image in a fixed location, despite the motion of intermediate lenses. This type of system is often used as a telextender to change the focal length of an existing lens.
Anaprism shows the use of tilted and decentered surfaces, prisms, and the 3-dimensional drawing routines that allow OSLO to draw a pictures of any solid objects that can be specified as a series of vertices and faces. The optical system itself is sometimes used to convert an elliptical diode laser beam to a circular shape.
Cherry contains a beam splitter, catadioptric mirror, and pickup constraints needed to specify a double-pass optical system where a beam passes through the same element in both directions. The system is a high-resolution design that has been adapted for microlithographic applications.
Dblgauss is a starting design for a conventional photographic objective of the type often used for 35mm single-lens reflex cameras.
Demotrip is a Cooke triplet used throughout OSLO as a demonstration lens. It is good for this purpose because it contains the degrees of freedom needed to illustrated several optical principles, uses vignetting as a design variable, and is relatively straightforward to understand. The Cooke triplet is probably the most common extended field lens ever designed.
Diodassy is an example of combining two other systems (anaprism and diodcoll) to collimate the beam from an astigmatic diode laser. OSLO can accommodate astigmatic sources directly, without the need for an ancillary system that provides an approximate model. The example shows the use of spot diagrams and point-spread-function calculations.
Diodcoll shows a practical lens in which the difference between aplanatic and paraxial ray aiming is clearly visible. Paraxial ray aiming is used in many optical design programs, but it does not provide a good model for systems that have a large numerical aperture on the object side. Aplanatic ray aiming is based on the canonical coordinates introduced by H.H. Hopkins, and is generally more accurate for these systems. The optical system itself is a commercial design available from Melles Griot, used to collimate diode laser beams.
Ebert is a simple grating monochromator that uses a plane grating. It should be studied to understand telecentric systems, rectangular special apertures, off-axis field points as base operating conditions, and the use of diffraction gratings.
Germdiff illustrates the use of a diffractive surface to correct the chromatic aberration of an infrared system, as well as an aspheric to correct spherical aberration.
Grinlens shows the use of gradient-index materals to make a focusing element for a CD player. In this design, the gradient coefficients are used as variables. In an alternate approach, the gradient is predetermined and the curvatures are varied.
Grinrod is an example system designed using a hypothetical gradient material. It shows the way in which rays would propagate through a gradient-index light pipe. You should note that this example is carried out using strictly geometrical optics, and can only be applied to propagation through fibers when the fiber diameter is much larger than the single-mode spot size.
Hologram illustrates diffractive surfaces, as well as the difference in image quality that comes from making the second principal surface of an optical system curved instead of flat.
Hubble is the design formula used for the original Hubble Space Telescope. Note that the original telescope was not manufactured to this design, which caused the problem.
Lasrcomm is the final design of the laser communication system described elsewhere. It is combined with a tiny single-mode fiber to show the fiber efficiency calculations that are built into OSLO.
Lasrdblt is the final design of the air-spaced doublet described elsewhere. The example here uses this design to illustrate the thermal analysis capabilities of OSLO.
Magnifyr is a plano-convex singlet set up as a visual magnifier. It shows how to set up the pupils for such a system, and serves as a base system used to compare the performance of a Fresnel magnifier.
Magfrenl uses a Fresnel surface to correct the geometrical aberration and a diffractive surface to correct the chromatic aberration of a simple magnifier. This example can be used to see how to enter data for these systems, or more importantly to understand the difference between a Fresnel and a diffractive surface.
Mquartet is the best solution found to the design problem posed at the 1994 International Lens Design Conference. It is often used as a reference point for global optimization.
Nikofish is a wide-angle system with a field of view greater than 90 degrees. It shows the use of wide-angle ray-aiming mode to automatically locate the position and extent of the pupil in such systems.
Pentprsm shows the use of special aperture data, as well as 3d boundary (bdi) data, used to enter data for a pentaprism.
Perfmag2 is an example of a perfect lens. It should be studied to understand the difference between a perfect lens and a paraxial lens, as well as the definitions of aperture-based operating conditions used in OSLO.
Petzval is a starting design for a large aperture narrow-field photographic lens. The Petzval design has been around for more than one hundred years, and is still widely used.
Prismirr is the final system from the prism data-entry example. It can be used to check your results.
Riflscop shows the use of the pickup-length-minus (pkp lnm) command to hold a constant image location. Because this is commonly required in zoom systems, this command is often called a zoom solve.
Schmidt shows the application of an aspheric surface as well as an obstruction in the setup of a wide-field telescope.
Schwarz is a catoptric (i.e. containing only mirrors) system often used as a microscope objective. The system shows the use of reflective imaging surfaces, as well as the use of a star command to enter data for a common system.
Xarmdemo is a system that captures light over more than a hemisphere. It shows the use of extended-aperture ray-aiming mode to model a point light source for this application. It is instructive to use OSLO's interactive design windows to study the effects of moving the source.
Yagcavty shows the final design of the YAG laser cavity described elsewhere, and can be used to check your results.
Singelem illustrates the use of the ISO 10110 drawing routines in OSLO to make element drawings suitable for fabrication
Movie shows the propagation of a Gaussian beam through a simple lens, and shows the use of OSLO to make animated sequences of drawings, as well as the interesting optical effects encountered when focusing low-aperture Gaussian beams.
Walker provides references for the 11 designs contained in the public\len\demo\walker. You need the book "Optical Engineering Fundamentals" by Bruce Walker to pursue these references.
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