The Invention of Solid-State and Semiconductor Lasers in the Soviet Union

Despite severe limitations on the transfer of information and tacit knowledge across the Cold War Iron Curtain, the invention of masers happened in parallel and practically simultaneously in the US and the USSR. After the successful operation of the first ammonia masers in the Soviet Union, Alexander Prokhorov and Nikolai Basov explored other types of masers that could use more practical materials and generate radiation of different wavelengths. By 1959, like physicists and engineers in other countries, they turned their attention to lasers. They divided the laboratory team to pursue two independent paths. While Prokhorov's team bet on solid-state lasers using ruby and other crystals as media, Basov's team bet on semiconductor materials. Both teams drew from their experience and knowledge of masers and domestic research and development traditions. This chapter aims to study these approaches to the invention of solid-state and semiconductor lasers in the Soviet Union as cases of multiple inventions. Tapping primarily on sources from Russian archives, it aims to investigate how the Soviet teams went from masers to lasers. What were their aims? How did their research relate to previous studies conducted in the Soviet Union? How did their paths compare to those taken by physicists in the United States who were working on similar devices? How much did Soviet and US physicists know about each other? These are some of the questions that will drive our investigations. I hope the presentation will help frame the laser as a multi-invention pursued on both sides of the Iron Curtain and fill a lacuna in historical studies of the laser in the Soviet Union.