InAs-based intersubband quantum cascade (QC) lasers with an improved waveguide configuration are proposed. Calculations and analyses are presented to show that the waveguide configuration will enhance the optical mode confinement and reduce optical absorption loss. We also discuss how these QC lasers could be constructed. It is expected that the performance of these InAs-based QC lasers, with the proposed waveguide configuration and optimizations, will be significantly improved.