Illumination device and luminaire

An illumination device comprising:

• a pair of concave reflectors each made of a single acoustically absorbing and light reflective element and bordering, with an outer edge, on a light emission window, the pair of concave reflectors and the light emission window constituting a boundary of a reflector cavity, the pair of concave reflectors each having a reflective surface facing the light emission window, wherein the acoustically absorbing and reflective element is sufficiently rigid not to deform due to its own weight, wherein the single element of the pair of concave reflectors is configured to both absorb sound and reflect light in the illumination device, and wherein each of the pair of concave reflectors is attached to a top surface of a centrally positioned, elongated bridging element;
• a counter reflector made of a single acoustically absorbing and light reflective element and positioned such that a concave reflective surface of the counter reflector faces the reflective surface of each concave reflector, wherein the single element of the counter reflector is configured to both absorb sound and reflect light in the illumination device, wherein the counter reflector is attached to a bottom surface of the bridging element;
• and
• the bridging element configured to accommodate a light source on two opposing sides of the bridging element and being provided at or within the boundary of the reflector cavity in between the counter reflector and the reflective surface of each of the pair of concave reflectors.