Masers tended to be complex, low power devices, and although there are maser amplifiers, one never hears about high power masers or much about masers at all. Why?
For one thing, there are a variety of adequate alternatives in the microwave region of the E/M spectrum – magnetrons, klystrons, and traveling wave tubes, to name a few that can handle significant power. After all, the simple inexpensive magnetron in your microwave oven is a coherent (relatively) monochromatic source of 2.45 GHz (12 cm) microwave ‘light’. 🙂 Hydrogen masers are still in use, as time standards. They are low power of course, but of high accuracy and high expense. Something along the lines of $500,000 apiece. So, next time I find one at a garage sale, I’ll consider going at least to $10. 🙂 (From: William Buchman (billyfish@aol.com).) The history of radio, then microwaves, and coherent optics is that power oscillators were used initially. The problem is that power oscillators usually give poor waveform quality. If a good amplifier is available, experience has been that it is easier and cheaper to make a high quality low power oscillator and then build up the power to the
