Olsen began his career at Bang & Olufsen in 1949 as a furniture designer. He was then commissioned to design loudspeakers for the brand, leading to the creation of the famous Beolab 5000 loudspeaker in 1967. This loudspeaker was highly acclaimed for its innovative design, which combined organic shapes with modern materials such as aluminum and plastic.
Over the years, Olsen continued to work on many other products for Bang & Olufsen, including vinyl turntables, radios and televisions. He was known for his minimalist, elegant approach to design, which influenced many other consumer electronics designers.
Apart from his work at Bang & Olufsen, Olsen also worked on design projects for other brands and was involved in professional design organizations in Denmark. His contribution to the design industry has been recognized with numerous awards and distinctions throughout his career.