The Lightoven was invented by Hartmut Ehmler, PhD in physics. He had done research work on nuclear fusion for several years before he turned to solar cooking.
When packing for camping holidays, he realized the solar cooker bought in the USA was too large for the car's trunk.
Is there a way to construct a small size yet powerful solar cooker, he thought. He experimented for one year with different prototype reflectors and cooking jars and compared them to existing solar cooker models. By an interplay of theory and experiment, he was able to optimize the Lightoven and transform it into a utilizable product.