Ideas and stumbling blocks in quantum electronics

Early developments related to quantum electronics are considered with the objective to find the reasons why the field of quantum electronics took as long as it did in getting started and why the build up was initially not more rapid. It is found that unnecessary delay occurred in part because quantum electronics lies between two fields, physics and electrical engineering. In addition to conceptual stumbling blocks which affected the course of quantum electronics, in the early days there was also a limited appreciation of the potential of this field. It is believed that lasers might well have been invented during the 1925-1940 period, although this would have been more difficult because of a lack of certain techniques which were further developed in later decades. Such techniques are related to good optical coatings, flash tubes, and improved varieties of infrared materials and detectors.