QUANTUM-WELL PRESSURE SENSORS

The possibility of calibrating very high pressures (up to 10 GPa) by t he shift of the optical spectra of semiconductor quantum wells is disc ussed. The photoluminescence of GaAs/AlGaAs wells is shown to be usefu l up to 4 GPa, the absorption in InGaAs/GaAs wells up to 5 GPa. In bot h cases 0.1% accuracy can be achieved and the pressure shift of the li ne does not depend on temperature. Other material combinations (like I nGaAs/InAlAs on InP) should extend the pressure range to 10 GPa. Quant um-well laser diodes operating in a single mode could serve as extreme ly precise pressure sensors but they should be specifically designed f or that application. Quantum-well layers deposited on a GaAs or on a S i diaphragm might be useful for measuring by optical means the strain field in the diaphragm.