Abstract

The combined nonlinear optical properties of intersubband and interband transitions in quantum wells have received considerable attention owing to their enhanced susceptibilities compared to bulk properties and potential applications in devices such as ultrafast optical switches and modulators. Indeed efficient nonlinear wave mixing between a near-infrared (NIR) pump (interband resonance) in presence of an intense terahertz (THz) beam (intersubband resonance) in quantum wells systems has been previously demonstrated to generate THz-optical sidebands i.e. E_NIR ± nE_THz where n is an integer [1]. However, the THz radiation is provided by a Free Electron Laser (FEL). Recently, we have demonstrated [2, 3] that these types of resonant nonlinear processes can be realized using quantum cascade lasers (QCL) [4]. These previous demonstrations have been performed using THz QCLs and thus inherently limited to cryogenic temperatures. In this work we demonstrate sideband generation up to room temperature between a resonant near-infrared beam and a mid-infrared (MIR) QCL. MIR QCLs are considerably more powerful than their THz counterparts and operate at high temperatures and here we show that the large phase mismatch between the NIR and MIR beams can be compensated using resonant nonlinearities.

© 2015 IEEE