Technical Description

This technical description provides an overview of the features included in the CODE V optical design and analysis software. For detailed program specifications, go to our CODE V Technical Specifications page.

For additional information on specific platforms and hardware requirements, or for lease prices, call ORA or send mail to service@opticalres.com.

• General
• Optimization
• Geometrical Optical Performance
• Superior Productivity
• Wave Optical Performance
• Illumination Analysis
• Physical Characteristics
• Tolerance Analysis
• Systems Analysis
• Graphics
• Unique Capabilities
• Documentation
• Program Availability

CODE V is an integrated system of modules, allowing a wide variety of optical computations to be performed on a common input lens data base. The various functions and major capabilities of CODE V are grouped into what are referred to as "options"; this term does not imply that they are optional to the customer or licensee in terms of being able to obtain CODE V without them, but optional in the context of program usage.

Considerable attention has been paid to making the CODE V program easy to use, without sacrificing flexibility or power. A graphical user interface (GUI) is provided, allowing users to navigate around the program by the use of pulldown menus and toolbar buttons, eliminating the need to remember numerous commands; however, commands can be used as well, or a combination of menus and commands. Frequent CODE V users often migrate to command mode, at least for the options they use most often. A library of over 2400 lens models from patents and other sources also contribute to ease of use by providing many possible starting points for new designs.

Extensive on-line help is integrated into the program. This allows users to obtain help on any lens data topic, CODE V option, or immediate command (input/output, etc.). In addition, context sensitive help gives help on the screen currently active. The on-screen help includes all the information and graphics available in the three-volume reference manual in a convenient and easily searched format.

Lenses without symmetry, i.e., systems with three-dimensional tilts and/or decenters, are easily input and modeled in CODE V, and all the analyses, image evaluation options, and optimization are carefully designed to handle such systems.

A wide variety of surface types are available, including diffraction gratings, generalized aspheric surfaces, and holographic surfaces. In addition, the user can create a user-defined surface type, allowing optimization and analysis of specialized surface types that have not been anticipated in the program. Features such as solves and pickups simplify the definition of lens models. Visual Systems can be analyzed in angular units and accomodation can be varied during optimization.

Gradient-index materials can be defined and used as well as can lens arrays (such as GRIN-rod arrays). The capability to handle non-sequentially traced surfaces is also provided; in this case the surfaces are ray traced in the order they are encountered by the light rays rather than the order in which they are entered. A given physical surface is entered only once, but may be encountered many times by the same ray. This facilitates the ray tracing and analysis of a number of special types of optical systems; these include systems with roof mirrors or prisms, corner cubes, light pipes and light collectors of various types, segmented windows, and resonators.

Systems with up to 21 different configurations, each of which may contain up to 25 different object points, can be simultaneously optimized or analyzed. This multi-configuration (zoom) feature can be used in the design of conventional zoom lenses as well as for many other applications. These include systems with interchangeable elements, reversible components, scanning systems, and systems corrected for multiple object and image conjugates.  A general pick-up capability allowing coupling of different types of variables can be used to set up the system for analysis and optimization.

A very powerful programming language called Macro-PLUS(tm) is integrated with CODE V. This is a modern, high-level programming language within CODE V which encompasses the following separate but related aspects of CODE V command mode usage (macros can be written in command mode and run from either command or GUI mode):

• Storing of commands for later execution from a file
• Freedom to use an arithmetic expression in place of a numeric input item
• Access to a broad range of CODE V maintained and calculated data
• User-defined variables, arrays, and functions
• Conditional and looping constructs (FOR, IF, UNTIL, WHILE)
• User-controlled input/output statements with sophisticated format control
• Ability to read from and write to text files stored on disk
• Storing of any CODE V output in the Worksheet Buffer(tm) for later manipulation

A growing library of macros, some written by ORA and some by users, is provided with CODE V.

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The CODE V optimization option (AUTO) provides the utmost in convenience, flexibility, and power to the lens designer. The error function (sometimes called a merit function) used during optimization can be any one or combination of the following:

• Transverse ray errors for pre-stored ray patterns (CODE V default)
• Wavefront variance for pre-stored ray patterns
• MTF at user-selected spatial frequencies (uses pre-stored ray patterns); this powerful capability uses wavefront differentials to achieve optimization speeds that are very fast (often equal or within a factor of two of using transverse ray or OPD-based merit functions).
• User-defined quantities (including Zernike wave front coefficients) based on a user-defined ray pattern

In addition to the above, any constraint (predefined or user-defined) can be included in the error function, allowing unlimited flexibility in error function definition.

The default constraint control method of Lagrangian multipliers provides for very precise control of boundary conditions without requiring manipulation of constraint weights vs. error function weights. Constraints can be imposed as equalities or as one- or two-sided bounds. General constraints to control lens vertex and edge thicknesses and axial and edge air gaps between elements are always imposed without the need for the user to explicitly enter them. This ensures the results of optimization are always manufacturable.

A large number and variety of predefined specific constraints are available to the users; in addition, for unusual requirements, the user can define special constraints (user-defined constraints) that allow the control of complex arithmetic relationships between first- and third-order quantities, constructional parameters, real-ray data, and even general functions defined in the Macro-PLUS language. These features, combined with an ORA-modified damped least squares optimization algorithm, provide an extremely powerful optimization capability in CODE V. A unique convergence method allows for fast optimization of very complicated systems.

CODE V also has Global Synthesis^®, the only proven practical and useful global optimization algorithm for real-world problems (i.e., problems with up to 100 variables and many dozens of hard constraints). Global Synthesis provides multiple, different, locally optimized solutions, each meeting all the constraints imposed. Global Synthesis has proven to  be an effective design tool for many types of lenses, including zoom systems. Many designs which benefitted from the unique power of Global Synthesis have been incorporated into real-world products that are currently being manufactured.

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A number of options are available to analyze the geometrical optical performance of the optical system. These include third-order aberration analysis, real ray tracing, MTF and square-wave responses, radial energy distribution, line spread distributions, detector energy analysis, scanned quadrant detector analysis, cat's eye diagrams, footprint analyses, and spot diagrams. Fifth-order analysis is available through an ORA-supplied macro. With the exception of some diagnostic calculations, all geometrical calculations are polychromatic (using up to 21 wavelengths and spectral weights defined as part of the lens data).

The CODE V beam propagation option computes the Gaussian beam size and orientation and waist locations and sizes; it can be used with asymmetric surfaces and tilted/decentered systems, including systems that generate "general astigmatism." This capability is particularly important in the design and analysis of laser scanners.

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CODE V helps its users to obtain accurate results quickly and easily - the very essence of productivity. Ease-of-use is an important factor in productivity. A simple graphical user interface (GUI) allows novice and occasional users to get basic results quickly with familiar pulldown menus and other simple mouse operations. Frequent users find that the logical command structure and intelligent default assumptions help them to solve problems with efficiency and confidence. Advanced users appreciate CODE V's completeness and the built-in Macro-PLUS programming language that allows them to customize CODE V output easily.

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Several CODE V options provide diffraction evaluations. The RMS wavefront error and Strehl definition, the polychromatic point spread function, encircled energy, and MTF can all be computed. A partial coherence option computes the image intensity of two-dimensional objects under the conditions of partially coherent illumination with varying polarization effects. A coupling efficiency option computes the coupling efficiency of a diffraction image into a single mode fiber. Both scalar and exact vector diffraction calculations are available and both polarized and unpolarized light (or partially polarized light) can be simulated, including the polarization effects of multi-layer coatings (absorbing or not) and birefringent materials. All wave-based calculations are polychromatic. The diffraction based Beam Propagation Option (BPR) allows the performance evaluation of an optical system with f-numbers such as laser printers to include the effect of residual aberration, apodization, and beam clipping at internal surfaces (including spatial filters) to be modeled accurately. Intensity and wavefront data at any intermediate or image surface can be computed to allow a thorough understanding of the propagation of a beam through an optical system.

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The LUM option allows you to perform illumination analyses on systems modeled from the source to the receiver or from the receiver to the source. This option traces thousands or even millions of polychromatic rays through the system and computes the illuminance distribution across a receiver grid. Multiple sources can be specified, and the shape and spatial and angular radiance distribution of each source can be specified. Several forms of numeric and graphical output are available.

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Options are included for the computation of lens transmission (including the effects of single or multilayer coatings and polarization), weight and center of mass, and ghost image analysis. A narcissus calculation computes the equivalent differential temperature of integrated surface detector retro-reflections, useful for scanning infrared system design.

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In addition to tolerancing, there are a number of fabrication-related features that are very useful. A special constructional data output makes the system data more understandable to the lens mount designer or shop. The COST option provides approximate blocking factors and blank costs, important considerations in high volume production. An automatic test plate fitting capability eliminates most of the work involved in fitting a design to test plates and typically fits more surfaces to plates than other commonly used methods. An interferogram interface allows for real-time alignment of complex optical systems when used in conjunction with Zygo, WYKO, or Phase Shift Technology interferometers. Interferograms can also be attached to surfaces to incorporate measured data into lens models.

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Computations which aid in evaluating the performance of the total optical system are also included in CODE V. A spectral analysis program cascades specified detector, black body, or filter responses to provide a system spectral response curve, and computes appropriate sampling wavelengths and weights for polychromatic computations. The multi-layer option (MUL) analyzes and/or optimizes the structure of a multi-layer coating stack made from dispersive or non-dispersive layers, with or without absorption. Anti-reflection coatings and various types of filters can be designed with this feature. The coatings can be attached to surfaces in the lens to analyze their actual performance as used in the lens (this is especially important for transmission and polarization analyses). Environmental analysis simulates changes in ambient temperature and pressure in the optical system, including expansion of lens spacers, radial thermal gradients, and thermal changes of optical properties. Transmission analysis simulates the transmission of an optical system including the effects of coatings, absorption and polarization.

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A wide variety of "report-ready" graphics are included as part of CODE V. They include:

• Lens layout (including 3D perspective plots with hidden line removal)
• Lens and component fabrication drawings
• Spot diagrams
• Ray intercepts (fans)
• Optical path differences (fans)
• Coddington field curves
• Field plots of distortion, astigmatism, RMS spot size, or RMS wavefront error
• MTF vs. frequency at a specific focus
• MTF vs. focus at a specific spatial frequency
• Wavefront deformation (contour map or perspective view)
• Diffraction image intensity (contour map or perspective view)
• Image intensity with partially coherent illumination
• Color contour plots of wavefronts, images, and interferograms
• 3-D shaded solid modeling of lens systems
• Color displays of pupil aberration or diffraction PSF output

In addition, a user graphics option allows plotting of multiple x,y data sets on a single plot; these data sets can be user-computed or extracted from CODE V output. Line, contour, raster, vector, and oblique plots can be produced. Special macros supplied allow the user to create custom plots or graphics of any type.

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In addition to tolerancing, there are a number of fabrication-related features that are very useful. A special constructional data output makes the system data more understandable to the lens mount designer or shop. The COST option provides approximate blocking factors and blank costs, important considerations in high volume production. An automatic test plate fitting capability eliminates most of the work involved in fitting a design to test plates and typically fits more surfaces to plates than other commonly used methods. An interferogram interface allows for real-time alignment of complex optical systems when used in conjunction with Zygo, WYKO, or Phase Shift Technology interferometers. Interferograms can also be attached to surfaces to incorporate measured data into lens models.

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ORA provides complete, comprehensive documentation for CODE V which is updated regularly along with the software and includes the following documents:

• CODE V Reference Manual - a comprehensive description of the program function and usage, including numerous examples, (provided online in Adobe Acrobat PDF format).
• Prompting Guide - convenient, concise reference for the command mode user, containing a brief description of all the program commands, syntax, and arguments.
• Introductory User's Guide - introductory manual intended for the new user.
• Test Drive - introduction to using CODE V showing use of the GUI.
• Photonics Modeling Guide - step-by-step instructions for setting up several common telecom systems.

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ORA believes that full-time technical support and regular program updates, including new and innovative features, are important parts of CODE V and contribute to customer success. Because of this, CODE V is never sold; it is leased under several license forms, all of which include monthly or annual license fees. Every CODE V license includes free, full-time technical support (including a toll-free hot line in the U.S. and Canada) and regular software and documentation updates.

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