Optical Design

RCI has designed optical systems for more than 100 different customers spanning a variety of project applications such as ruggedized space-based & aerospace optics, UAVs & military, stray light & illumination design, hyperspectral & multispectral systems, lithography & inspection, bio-medical & medical applications and much more. Our team has over 50 years of combined optical engineering experience giving RCI a remarkable aptitude for optical system design. RCI uses Zemax™, CODE V™, FRED™ and ASAP™ as well as in-house software called GELOE. GELOE provides unique stray light and opto-mechanical analysis capabilities and is often used as a tie-breaker between Zemax™ and CODE V™ as it approaches the analysis from a much different point of view. GELOE also has the ability to integrate the mechanical CAD model into the stray light analysis for a more comprehensive optimization.

RCI has developed many in-house macro routines using Matlab, Mathcad and Python. Some of these routines include powerful tolerancing algorithms that accurately predict the allowable lens and mechanical fabrication errors as well as the assembly and alignment processes. Our group specializes in optical design evaluation as well, where RCI is able to optimize a customer's design for manufacturability and production. RCI's wide range of optical design expertise is tailored to the fine balance of cost and quality, and our track record for customer satisfaction speaks for itself.

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Sensitivity, Tolerance and Compensator Analysis

Over the course of several years, RCI has developed and perfected in-house tolerancing routines which are heavily depended on for high perfromance, tight tolerance systems. The routines utilize Zemax's ZPL macro language in conjunction with MathCAD and Python to accurately predict the as-built performance of optical systems.

Each optical system requires a unique analysis that usually begins with a sensitivity run. The results from the sensitivity analysis are used to define compensators such as focus control, re-spacing, decenterable lenses and/or groups, etc. Script files are created from performance metrics and compensators which are used to draft the initial system tolerances. With a script file in place, 100+ Monte-Carlo runs are executed in Zemax and are optimized by applying the defined compensators. Our routine compiles the results in scatter plots where they are used to evaluate the percent yield of the fabrication and assembly process. Typically these results require a feedback loop or iteration until the percent yields are acceptable.

RCI has relied on these routines to predict the performance of prototypes such that they meet spec the very first time they are built. These routines are automated and do not require exstensive labor which in the end offers our customers high value analysis at a lower cost.

Straylight

RCI has a strong straylight analysis team led by Al Greynolds who originally teamed up with Mitch Ruda in the 1980's. Ruda-Cardinal has an extensive history of successful straylight analyses including programs such as the Rockwell, Thousand Oaks blue-green laser submarine com receiver, SLCR development for the NAVY and ultra-low ghost design for Lockheed Martin's PNVIS system, etc. RCI currently uses three analysis programs: ASAP™(originally written by Al while employed at a different company), FRED™, and GELOE, an in-house program written by Al while at RCI.

GELOE incorporates system information from various optical and mechanical design programs which allows the software to produce realistic models of any optical assembly. In addition to GELOE's multiplatform software integration, it can import external sources into the model. These external sources can be setup to propagate non-sequentially through a system and can be used to evaluate how much (if any) light is seen by the sensor. From this kind of analysis and modelling, baffles and other light traps can be engineered to mitigate the effects of these sources. Ghost image determinations, veiling glare modelling and ghost analyses are also part of RCI's straylight capabilities where lens radii, particulate/contamination density and A/R coatings on optical surfaces are part of the optimization process.

Radiometric and Thermal Analysis, Mathematically Modeling

Ruda-Cardinal has decades of experience in engineering optical systems that require optimized performance specifically tailored to harsh environmental conditions. Product development and manufacturing has included optical systems for the automotive, military, aerospace and space-based industries, all of which have had varying degrees of environmental specifications and requirements. A broad temperature range such as -40°C to +85°C can have devastating effects on the performance of an optical system if the design has not been engineered correctly. Ruda-Cardinal has extensive experience in passive athermal optical system design where optical performance such as image quality and focus drift are well controlled across a broad temperature range. Passive athermal correction is done without the need for motorized mechanics, heaters or other compensators. A thorough athermal design must include thermal stress analyses that examine the mounting of glass elements, CTE mismatches and material strengths.

In addition to a thermal stress analysis, the of the glass must also be taken into account. Optics systems can behave in mysterious ways, and as a lens heats up or cools down, the focus position of an imaging system can either increase of decrease. By making good use of material selection and multi-configuration modeling, the properties can be well understood such that the design works properly.