Refractive index of AlInGaAs layers in the transparent wavelength region

Compared with InGaAsP as an optical material system, AlInGaAs possesses advantages like (l) a larger conduction band offset that improves electron confinement; (2) a smaller valence-band discontinuity that alleviates the hole capture problem, resulting in a more efficient carrier sweep out; (3) AlInGaAs is better suited for the realization of continuous graded index separate-confinement-heterostructure (GRIN-SCH) lasers, where very efficient carrier capture process in a thin quantum well active layer has been demonstrated. Although all the devices mentioned above incorporate layers of AllnGaAs, little is known about their refractive index which is essential to optimize those devices. This paper calculates this refractive index in the transparent wavelength region