Our team consists of industry’s most innovative technologists and seasoned executives in the business of optoelectronic component design, manufacture, packaging and applications. We have a strong customer focus, and are dedicated to providing products with the highest levels of performance, consistency and reliability. We are committed to doing business with both customers and vendors with the highest levels of integrity and fairness.

Matthew Dummer

VCSEL Design

Dr. Dummer is responsible for the design of unique optoelectronic devices forming the basis of Vixar products. He has 10 years of experience in the design, fabrication, test, packaging and integration of high-speed optoelectronic devices. As part of his thesis research at the University of Santa Barbara, he demonstrated high functionality photonic integrated circuits (PICs) for photocurrent-driven wavelength conversion and monolithically integrated tunable transceivers operating up to 40 Gb/s. He is the author or co-author of over 20 publications and conference presentations. Dr. Dummer received his M.S. and Ph.D. in Electrical Engineering from the University of California at Santa Barbara, and his B.S. in Electrical Engineering from the University of Minnesota.

Founder Chief Executive Officer

Mary Hibbs-Brenner

Co-founder and CEO

Dr. Hibbs-Brenner brings 30 years of proven expertise guiding innovative semiconductor and optical technologies into the commercial market.

Prior to co-founding Vixar, Dr. Hibbs-Brenner held business development, technical management, and research positions at Honeywell. She was responsible for initiating the company’s VCSEL business and held the position of Director of Research and Development within that business.

The Honeywell VCSEL business experienced rapid growth. VCSEL products from Honeywell and others helped to fuel the growth of the Internet by becoming the laser source of choice for Local Area Networks (LANs) and Storage Area Networks (SANs). This business was sold to Finisar in 2004. Dr. Hibbs-Brenner also served as a business development lead within the Honeywell Technology organization, developing business plans for bringing new technologies to market.

Dr. Hibbs-Brenner has an MBA from the Carlson School of Business, University of Minnesota, a Ph.D. in Materials Science from Stanford University, and a B. A. in Physics from Carleton College. She spent two years doing post-doctoral research at the University of Linkoping, Linkoping, Sweden.

Dr. Hibbs-Brenner has seven patents, and over 50 publications and invited presentations.

William Hogan

Product Development

Mr. Hogan oversees all of the product and package development for Vixar products. He has 30 years of experience working in electro-optics, including fiber optic communications and optical disk technology at IBM, JDSU, Rohm and Haas, Nuvotronics, and Vixar. He brings to the product development effort both depth and breadth of expertise spanning optoelectronic packaging, reliability evaluation, and system integration of optoelectronic components, integrated circuits, electrical, optical and mechanical design. He has been granted 44 patents and is the co-author of numerous technical papers and conference presentations. Mr. Hogan has an M.S. in Optical Engineering from the University of Arizona, an M.S. in Electrical Engineering from the University of Minnesota, and a B.S. in Electrical Engineering from Michigan State University.

Founder Chief Technology Officer

Klein L. Johnson

Co-founder and Chief Technology Office

Dr. Johnson is a co-founder of Vixar. He brings a rich background of technical and engineering leadership in optoelectronic chip design and development. His 12 year career at Honeywell as a research scientist and project leader spanned a broad range of research and development optoelectronic device and packaging efforts, high speed VCSEL chip and package design, including the development of polymer and glass waveguides, a very high bandwidth array transceiver, optoelectronic integrated circuits, and rugged packaging for military applications. Dr. Johnson has a Ph.D. in Electrical Engineering from the University of Minnesota and a B. A. in Mathematics and Physics from St. Olaf College. Dr. Johnson has 3 patents, 7 patent applications, and is the author/co-author of multiple papers and conference presentations.

Lori Milbrandt


Lori Milbrandt, CPA (Inactive License), is a Contract CFO for several start-up companies. She has over 30 years of accounting, finance and HR experience. Prior to becoming a Contract CFO, she held several management-level positions with companies including Microvena, ev3 and DiaSorin (fka Incstar). She spent the first seven years of her career with KPMG, one of the largest international audit, tax and advisory firms. She received her degree in accounting from the University of Wisconsin-Eau Claire and a Masters in Finance from the University of St. Thomas.

Business Development

Todd Schieffert

Business Development

Todd Schieffert is a highly accomplished technology and communication executive with over 30 years of experience in general management, sales, business development, marketing and product management. Todd has demonstrated success in managing companies and organizations, creating vision, developing domestic and international strategic business plans, launching new product programs, building strategic relationships, securing revenue, and driving corporate value. Todd has successfully raised capital to start new companies and new product portfolios.

Todd’s most recent position was Senior Vice President of McWane Inc. where he focused on technology evolution, new markets, and new products for the public safety and mobile wireless market segments. Prior to McWane, Todd was President of Comtech International, a mobile wireless repeater and distributed antenna systems company. Todd’s past experience includes President of Broadband Wireless Access Consulting and at ADC Telecommunications where he held numerous executive leadership positions in Sales, Marketing, Business Development, and Product Management. As an active leader in the Wireless Group, Todd created market solutions for 802.11 Wi-Fi, IP Wireless Gigabit Transport (E-Band), 802.16e 4G WiMAX and LTE. Todd holds a bachelor’s of science degree in business from Saint John’s University.

Bill Sheppard


Bill Sheppard leads Vixar’s operations, responsible for manufacturing, supply chain and fulfillment. He has more than 30 years of global experience with Fortune 100 companies, small business, and early-stage investor-backed technology companies. During his 18-year career with Intel, he filled a variety of roles including Vice President of the Technology and Manufacturing Group. He managed operations in 11 countries, directed manufacturing site development, operations, purchasing, materials, government relations, real estate, environmental, health, safety and security. His worldwide organization included a team of 15,000 employees and contractors with a combined $5B in annual operating and capital expenditure budgets.

More recently, Bill has focused on building small businesses and early-stage investor-backed technology companies. He served as CEO and board director for three early-stage companies, Andigilog, MicroLab, and Micro Photonix Integration leading product development, funding, recruiting, and operations. Throughout his career, he has held board and advisory roles guiding strategic reviews, restructurings, governance changes, operations, funding, and partnering at corporate and nonprofit organizations. He served in board and advisory board roles with startups as well as with larger organizations – Norwest Bank Community Advisory Board, United Way of New Mexico, the Albuquerque Chamber of Commerce and Folsom Chamber of Commerce. Bill holds a Bachelor of Science degree from the University of San Francisco and served in the US Navy.

Ben Olson

Quality and Reliability

Dr. Olson is responsible for ensuring that the product shipped by Vixar meets our customer quality and reliability requirements. He has 10 years of experience in semiconductor physics and device characterization, optics and optoelectronic devices. Before joining Vixar, he held a prestigious Central Intelligence Agency postdoctoral fellowship at Sandia National Labs developing next generation IR sensor technology. Dr. Olson received his Ph.D. in Physics from the University of Iowa in 2013, where he received an Outstanding Dissertation Award, awarded once every two years. He received a B.A. in Physics from Gustavus Adolphus College in 2007.