Interferometer measurements of terahertz waves from Bi2Sr2CaCu2O8+dmesas

We fabricated rectangular mesa structures of superconducting Bi 2 Sr 2 CaCu 2 O 8+ d (Bi2212) using e-beam lithography and Ar ion beam etching techniques for terahertz (THz) emission. c -axis resistance versus temperature ( R – T ), current–voltage ( I – V ) characteristics and bolometric THz power measurements were performed to characterize Bi2212 mesas. The emission frequency of mesas was determined using a Michelson interferometer setup which also demonstrates polarized emission. Interference patterns of THz radiation from Bi2212 mesas were detected by various detectors such as a liquid helium cooled silicon composite bolometer, a Golay cell and a pyroelectric detector. An emitted power as high as 0.06 mW was detected from Bi2212 mesas. For the first time, most of the pumped power was extracted as THz emission from a Bi2212 mesa. The radiation at 0.54 THz was detected using the Michelson interferometric setup.