An optical assembly, comprising: an optical device comprising an optical surface; and a pre-formed encapsulant film that substantially or entirely covers the optical surface, the encapsulant comprising: a first layer comprising a first silicone-containing hot melt composition, the first layer having a first major surface and a second major surface; and a second layer comprising a second silicone-containing hot melt composition, the second layer having a first major surface and a second major surface, the second major surface of the first layer being in contact with the first major surface of the second layer; wherein the first and/or second layer is or includes a phosphor in the silicone-containing hot melt composition; and wherein the first and/or second silicone-containing hot melt composition includes at least one resin-linear composition containing an organosiloxane block copolymer containing: 40 to 90 mole percent disiloxy units of the formula [R 1 2SiO 2/2], 10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2], 0.5 to 25 mole percent silanol groups [=SiOH]; wherein: R 1 is independently a C 1 to C 30 hydrocarbyl, R 2 is independently a C 1 to C 20 hydrocarbyl; wherein: the disiloxy units [R 1 2 SiO 2/2] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2] per linear block, the trisiloxy units [R 2 SiO 3/2] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, at least 30% of the non-linear blocks are crosslinked with each other and are predominately aggregated together in nano-domains, each linear block is linked to at least one non-linear block; and the organosiloxane block copolymer has a weight average molecular weight of at least 20,000 g/mole, and is a solid at 25°C; and further wherein the first and/or second layer or first and/or second silicone-containing hot melt composition forms a gradient. an optical device comprising an optical surface; and a pre-formed encapsulant film that substantially or entirely covers the optical surface, the encapsulant comprising: a first layer comprising a first silicone-containing hot melt composition, the first layer having a first major surface and a second major surface; and a second layer comprising a second silicone-containing hot melt composition, the second layer having a first major surface and a second major surface, the second major surface of the first layer being in contact with the first major surface of the second layer; wherein the first and/or second layer is or includes a phosphor in the silicone-containing hot melt composition; and wherein the first and/or second silicone-containing hot melt composition includes at least one resin-linear composition containing an organosiloxane block copolymer containing: 40 to 90 mole percent disiloxy units of the formula [R 1 2SiO 2/2], 10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2], 0.5 to 25 mole percent silanol groups [=SiOH]; wherein: R 1 is independently a C 1 to C 30 hydrocarbyl, R 2 is independently a C 1 to C 20 hydrocarbyl; wherein: the disiloxy units [R 1 2 SiO 2/2] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2] per linear block, the trisiloxy units [R 2 SiO 3/2] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, at least 30% of the non-linear blocks are crosslinked with each other and are predominately aggregated together in nano-domains, each linear block is linked to at least one non-linear block; and the organosiloxane block copolymer has a weight average molecular weight of at least 20,000 g/mole, and is a solid at 25°C; and further wherein the first and/or second layer or first and/or second silicone-containing hot melt composition forms a gradient. a first layer comprising a first silicone-containing hot melt composition, the first layer having a first major surface and a second major surface; and a second layer comprising a second silicone-containing hot melt composition, the second layer having a first major surface and a second major surface, the second major surface of the first layer being in contact with the first major surface of the second layer; wherein the first and/or second layer is or includes a phosphor in the silicone-containing hot melt composition; and wherein the first and/or second silicone-containing hot melt composition includes at least one resin-linear composition containing an organosiloxane block copolymer containing: 40 to 90 mole percent disiloxy units of the formula [R 1 2SiO 2/2], 10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2], 0.5 to 25 mole percent silanol groups [=SiOH]; wherein: R 1 is independently a C 1 to C 30 hydrocarbyl, R 2 is independently a C 1 to C 20 hydrocarbyl; wherein: the disiloxy units [R 1 2 SiO 2/2] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2] per linear block, the trisiloxy units [R 2 SiO 3/2] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, at least 30% of the non-linear blocks are crosslinked with each other and are predominately aggregated together in nano-domains, each linear block is linked to at least one non-linear block; and the organosiloxane block copolymer has a weight average molecular weight of at least 20,000 g/mole, and is a solid at 25°C; and further wherein the first and/or second layer or first and/or second silicone-containing hot melt composition forms a gradient.