Emission Properties of Two-Photon Pumped InSb Laser under Magnetic Field

The magnetic tuning characteristics of InSb laser pumped by a TE CO₂ laser were studied. The tuning characteristic depended on the carrier density of n-InSb sample. For a sample with low carrier density, the emission energy shifted monotonously to higher energy with increasing magnetic field and only one linear shift varying as Δ\varepsilon{=}(\hbarω_c-|g_c|β H)/2 was observed at a high magnetic field. For a sample with high carrier density, the emission energy shifted to lower energy at a low magnetic field, and at a high magnetic field two linear shifts with different rates to higher energy varying as Δ\varepsilon{=}(\hbarω_c±|g_c|β H)/2 were observed. The polarization and the intensity of emission were also investigated. The zero-field emission energy was measured for samples with different carrier densities. A simple transition model is proposed, which can explain the observed magnetic tuning characteristics.