Schottky diodes are uniquely important as the critical non-linear element in room temperature detectors and frequency multiplied sources.As detectors,Schottky diodes can be used in frequency mixers,to translate spectral information to a lower frequency; they also find common application as direct video detectors where spectral information is not conserved.GaAs Schottky diodes will provide the front-end frequency conversion in a range of future meteorological satellites being developed in Europe and China.These applications require high sensitivity combined with long operational lifetimes and often long pre-launch storage times.In astronomy,Schottky based mixers are being proposed for future deep space missions where superconductor based detectors are not viable due to limitations of cryogenic storage for missions with long flight times and where electrical power consumption is a critical driver,excluding the option of active cooling.Finally,Schottky diodes are used extensively in ground based applications; in the laboratory environment these are common in both generic test and measurement equipment and in bespoke applications.In this paper,we finally consider some of the emerging applications in particle physics and beam diagnostics for synchrotron radiation sources.