Abstract

A transversely excited atmospheric CO₂ laser pumped far-IR laser has been used to prove the cyclotron resonance line shape of a 2-D electron gas at GaAs/AlGaAs interface for intensities up to 1 MW/cm². Samples with densities between 0.9 and 4.5 × 10¹¹ electrons/cm² at 1.7 K as determined by Shubnikov-de Haas resistivity measurements have been studied. The present work focuses on extending the range of frequencies beyond that reported previously.¹ The sample is mounted in the Faraday configuration inside a 10-T superconducting solenoid in an optical access cryostat. At far-IR frequencies between 8 and 120 cm⁻¹ the cyclotron resonance line shape is obtained by measuring the transmission as a function of the magnetic field. At high intensity the cyclotron resonance line shape broadens in a way consistent with carrier heating. The onset intensity for this nonlinear behavior increases with increasing frequency.

© 1987 Optical Society of America