The invention describes a light converting device comprising: a bonded layer stack comprising a light converter and a diamond layer, wherein the diamond layer is bonded to a bonding surface of the light converter, wherein the light converter is adapted to convert laser light to converted light, wherein a peak emission wavelength of the converted light is in a longer wavelength range than a laser peak emission wavelength of the laser light, wherein a refractive index of the diamond layer is bigger than a refractive index of the light converter, and a light outcoupling structure attached to a first surface of the bonded layer stack, wherein a second surface of the bonded layer stack is a light-entrance surface arranged to receive the laser light, wherein the bonding surface is arranged between the first surface and the second surface of the bonded layer stack, wherein a refractive index of the light outcoupling structure is at least 90% of the refractive index of the light converter, and wherein the light outcoupling structure is optically coupled to the first surface of the bonded layer stack such that total internal reflection of light traversing an emission path from the light-entrance surface to the light outcoupling structure is reduced. The invention further describes a laser-based light source comprising such a light converting device and a vehicle headlight comprising such a laser-based light source.