Interband Cascade Laser: Multi-Wavelength Generation and Mode Mixing

The multi-wavelength generation and nonlinear mode mixing in a new class of injection heterolasers - the interband dual-cascade laser with a tunnel junction, which separates two different quantum-well active regions integrated within a single waveguide, are obtained and investigated for the first time. The authors describe in detail the proposed design of the interband dual-cascade heterolaser suggested by Belyanin et al., (2003). The paper presents an intriguing experiment where the fabricated InGaP/GaAs/InGaAs laser oscillator with pulsed submicrosecond injection demonstrates simultaneous generation of a couple of the first-order modes at wavelengths 1.063 mum and 0.98 mum, and a couple of the third-order modes at wavelengths 0.951 mum and 0.894 mum. The observation of the sum-frequency and second-harmonic generation proves the efficient intracavity mode mixing owing to the second-order bulk nonlinearity of the heterostructure. The final goal of the paper, which is of particular interest for various applications, is an intracavity difference-frequency generation in the far-infrared and terahertz range offering a path to broadly tunable, room-temperature operated, injection-pumped sources. High second-order nonlinear susceptibility of semiconductor crystals and strong intracavity electric fields of the laser should provide high frequency conversion.