Laser gain properties of AlGaN quantum wells

Laser gain is investigated for AlGaN wurtzite quantum-well structures emitting in the wavelength range from similar to 270 to 340 nm. The calculations show that gain properties vary notably with aluminum concentration in the quantum well. The TE gain dominates over the entire spectral range, although an enhancement of TM gain is observed for AlGaN quantum wells with the high aluminum mole fraction. The calculations also predict an increase in threshold current density for the shorter-wavelength lasers.