A LITTLE-KNOWN precursor of the laser could find a host of new applications after researchers at Imperial College London produced a maser that can operate continuously at room temperature, overcoming a major limitation in their use. Masers (microwave amplification by stimulated emission of radiation) use the same principle as lasers but at different wavelengths. The first was demonstrated in 1953, but they have since faded into comparative obscurity, though they can be employed for timekeeping in ultra-precise atomic clocks and in some applications in radio astronomy and deep space communications.
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