© 2020, TUBITAK. All rights reserved.The research on dilute bismuth containing III-V semiconductor alloys and its applications are studied. These alloys are obtained by incorporating a small amount of Bi in the host semiconductor. The presence of Bi reduced the energy bandgap of the alloys. The bandgap and optical properties of InAs1− Bi, InP1-xBix, and InSb1− Bi alloy systems are investigated for optoelectronic devices. The optical properties of semiconductors are important to change the properties of device performance. The refractive index strongly depends on the direct bandgap of the semiconductor alloys. The bandgap of the In-V-Bi semiconductor layer can be engineered by means of adding bismuth into InAs, InP, InSb. In this work, the refractive indices and the optical parameters of the In-V-Bi alloys are investigated.