Abstract: A device for mixing light is disclosed. A mixer body has an aperture that preferably extends entirely therethrough. Light from multiple sources may be introduced on one side of the aperture and removed from the mixer on an opposite side thereof. Multiple reflections of the light between a surface of the body of the mixer that defines the aperture and surfaces of the body that define an exterior of the body promote the mixing of the light. One or more surfaces of the body may be roughened to further promote mixing of the light, for instance all exterior surface of the mixer body except the light entry which is preferably smooth. Another option that may be used alone or in combination with the noted roughening features is the inclusion of a plurality of reflective particles (e.g., metallic) embedded within the mixer body, bubbles embedded within the mixer body, or both. The device is particularly suited for applications where space constraints are an issue.