A stack of layers 100, a lamp, a luminaire and a method of manufacturing a stack of layers is disclosed. The stack of layers 100 comprises a first outer layer 102, a second outer layer 106 and a luminescent layer 104. The first outer layer 102 and the second outer layer 106 are of a light transmitting polymeric material and have an oxygen transmission rate lower than 30 cm3/(m2-day) measured under standard temperature and pressure (STP). The luminescent layer 104 is sandwiched between the first outer layer 102 and the second outer layer 106 and comprises a light transmitting matrix polymer and a luminescent material 108 being configured to absorb light according to an absorption spectrum and convert a portion of the absorbed light towards light of a light emission spectrum.

A lighting device (100) includes a housing (104) enclosing a housing interior (108), a light source (132), a light converter (136), and a color tuning device. The light source is configured for emitting a primary light beam of a primary wavelength (140) through the housing interior. The light converter includes a luminescent material (144) facing the housing interior and configured for emitting secondary light (156, 158) of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beam. The housing includes a light exit (124) for outputting a combination of primary light and secondary light. The color tuning device is configured for adjusting a position of the primary light beam relative to the luminescent material.

A lighting device (100) includes a housing (104) enclosing a housing interior (108), a light source (132), a light converter (136), and a color tuning device. The light source is configured for emitting a primary light beam of a primary wavelength (140) through the housing interior. The light converter includes a luminescent material (144) facing the housing interior and configured for emitting secondary light (156, 158) of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beam. The housing includes a light exit (124) for outputting a combination of primary light and secondary light. The color tuning device is configured for adjusting a position of the primary light beam relative to the luminescent material.

To provide a phosphor being chemically-thermally stable and having high luminous intensity if combined with LED of not exceeding 470 nm. A phosphor of the present invention includes: inorganic compound including: a crystal represented by Li.sub.1Ba.sub.2Al.sub.1Si.sub.7N.sub.12; a crystal represented by (Li, A).sub.3(D, E).sub.8X.sub.12; and an inorganic crystal having the same crystal structure as the crystal represented by Li.sub.1Ba.sub.2Al.sub.1Si.sub.7N.sub.12; and a solid-solution crystal thereof, which contains Li, A, D, E, and X elements (A represents at least one selected from Mg, Ca, Sr, Ba, Sc, Y and La; D represents at least one selected from Si, Ge, Sn, Ti, Zr and Hf; E represents at least one selected from B, Al, Ga and In; and X represents at least one selected from O, N and F), wherein M element (M represents at least one selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb) is solid-solved into each.