Meet the team

Ken Castle


B.S. Physics, University of Massachusetts, 1977

Ph.D. University of Arizona Optical Sciences Center, 1985

Dr. Castle, President, has over 30 years of experience in the optics field covering optical design, optical engineering, radiometry, stray-light analysis, assembly and test. Major military projects he has been involved with include STARLAB (involving a five off-axis parabolic relay that he aligned), NEMO (where he designed the pan-chromatic imager), AC-130 Gunship Program (involved with the targeting system optical design), and ARGUS (responsible for the alignment and testing of the diffraction-limited optics). He has also been associated with several commercial projects performing design, analysis, and testing tasks.

Ken is generally responsible for optical engineering and analysis, and ensuring that the mechanical department has the optical information necessary to move forward for each project. Ken's exceptional teaching skills are utilized in mentoring junior engineers in optical design, tolerancing, and testing. Ken also acts as a detective in analyzing problematic optical systems, finding a fix and optimizing their functionality. His acquired knowledge and years of experience allow him to visually assess aberrations and identify the adjustments necessary to output a diffraction limited system.

Ken's interest in optics started in high school when he tried to make a telescope for a science project. He has had a lifelong interest in astronomy, and still infrequently contributes observations to AAVSO and their variable star programs. His passion for perfection is often tempered by the engineering need to make it good enough, though beating the spec is still what is strived for. He still loves what he does, and looks forward to helping others learn to love optics as well. Ken has been a member of three professional societies for over 30 years: OSA, SPIE, and ASPRS.

Dr. Tilman Stuhlinger

Vice President

B.S. Physics and Astronomy, Vanderbilt University, 1975

M.S. Physics and Astronomy, University of Georgia, 1979

M.S. Optics, University of Arizona/Optical Sciences Center, 1981

Ph.D., University of Arizona, Optical Sciences Center, 1984

Dr. Stuhlinger, Vice President, is highly accomplished in the areas of optical testing and optical design/analysis utilizing CODE V, ZEMAX, and ASAP/Rabet. Tilman developed an in-house methodology to better analyze and critique optical system sensitivities and tolerancing. A world class designer with revolutionary thinking, he is knowledgable in fabrication techniques and capabilities. His intimate knowledge of RCI alignment and assembly processes coupled with his extensive experience make his analyses exquisitely accurate.

Among his many accomplishments, he is responsible for the following optical designs:

  • All-reflective space-based hyperspectral imager
  • Catadioptric panoramic imager
  • Analysis for National Ignition Facility
  • Tolerance analysis of next-generation space telescope
  • SmART Lens, winner of the Academy of Motion Picture Arts and Sciences (AMPAS) Scientific and Technical "Oscar" Awards 2009
  • Design of zoom lens and low stray-light objective for airborne surveillance system
  • Tolerancing of wide-field, high-resolution airborne surveillance objective
  • Design of non-imaging concentrator array for airborne radiometer
  • Design of superconic laser-diode collimator
  • Design of lithographic optical systems

John Mongelli


B.S. Optical Sciences and Engineering, University of Arizona, 2010

M.S. Optical Sciences and Engineering, University of Arizona, 2012

John Mongelli received his Masters of Science in Optical Engineering from the College of Optical Sciences, University of Arizona in 2012 as well as his B.S. in optics, University of Arizona 2010. John is the Director of Engineering at Ruda-Cardinal and has over 8 years of experience in the field of engineering. He has developed numerous test plans, alignment procedures and analysis routines using Matlab, Python and ZPL Macros. John has designed, toleranced, assembled and tested many different optical systems for several successful and diverse programs. Along with his technical expertise at Ruda-Cardinal, John also plays a vital role in business development, marketing and sales, proposals, contract negotiations and program management. John's outstanding leadership skills and deep technical understanding in optics markedly strengthens Ruda-Cardinal's extraordinary reputation and ever growing customer base.

Steve Holly


Steve Holly serves as Ruda-Cardinal's Production Manager and has over 18 years of experience in the technical field spanning a variety of different industries. His nearly 10 years of project management experience and broad technical background provides the necessary skill sets to efficiently supervise the production floor, maintain vendor relations and fill a crucial role in supply chain management. This vast technical knowledge and experience facilitates Steve's ability to asses and identify risks long before they become an issue. Steve's involvement with the ISO9001/AS9100 quality management system is critical in maintaining quality control, assurance, structure and continual development and improvement. Since Steve has become Production Manager in 2012, Ruda-Cardinal's procurement and labor overruns are at an all-time low where program schedule and delivery commitments are unprecedentedly satisfied. There are very few people who can organize a production team to produce the highest of quality products on time and under budget, and Steve Holly is one of them.

Giovanna Dietz

Office Manager

Giovanna Dietz is the Office Manager at Ruda-Cardinal and has over 8 years of experience working with engineers in a variety of roles. As Office Manager she handles project procurement, scheduling and cost tracking for each particular program at Ruda-Cardinal. Her knowledge and experience has provided her with the necessary skills to fill multiple roles within the company. Giovanna is responsible for Accounting, ISO audits and approval as well as time tracking, program budgets and invoicing. Her attention to detail and strong work ethics are not only highly valued by Ruda-Cardinal but are also much appreciated by our customers.