A solid solution-based optical material capable of transmitting infrared light, the solid solution-based optical material comprising at least two nano-sized phases intermixed in one another, wherein at least one of the at least two nano-sized phases is a solid solution containing a dissolved dopant, the dissolved dopant present in an amount sufficient to reduce a refractive index difference between the at least two nano-sized phases to about 0.2 or less when infrared light is being transmitted. Various embodiments are directed to related systems and methods. In one embodiment, the infrared light is visible infrared light, short-wave infrared light, eye safe infrared light, medium wave infrared light, long wave infrared red light, or combinations thereof.