Far infrared laser thermal spectroscopy of superconductors

An experimental technique is proposed for studying semiconductors whereby the power transmitted by an optically pumped FIR laser through thin superconducting films is measured at a fixed laser frequency while the sample temperature is swept through the superconducting transition temperature. Thus it is possible to set the photon energy near some significant value, such as the gap energy or a phonon energy, and then to use the continuous tunability of the temperature to search for interesting phenomena. Results for V3Si films show that the thermal method can return FIR data of good quality with the capability of resolving fine structure