An LED plant growth lamp spectrum, the spectrum including: a light wave of 500-599 nm and a light wave of 700-780 nm, where a ratio of the number of photons in the range of 500-599 nm to the number of photons in the range of 700-780 nm is 0.9-1.6:1. The LED plant growth lamp spectrum promotes indoor cultivation and growth of plants, and helps to increase the yield of medicinal components per unit area and per unit time in the factory production.

An LED plant growth lamp spectrum, the spectrum including: a light wave of 500-599 nm and a light wave of 700-780 nm, where a ratio of the number of photons in the range of 500-599 nm to the number of photons in the range of 700-780 nm is 0.9-1.6:1. The LED plant growth lamp spectrum promotes indoor cultivation and growth of plants, and helps to increase the yield of medicinal components per unit area and per unit time in the factory production.

A lighting device includes a wavelength conversion unit, a driving unit, and a light source. The wavelength conversion unit includes a main body and a fluorescent powder layer. The main body has a cylindrical outer surface. The fluorescent powder layer is disposed on the cylindrical outer surface. The driving unit is configured to drive the wavelength conversion unit to rotate around an axis. The cylindrical outer surface surrounds the axis. The light source is configured to emit light toward the fluorescent powder layer.

A lighting device includes a wavelength conversion unit, a driving unit, and a light source. The wavelength conversion unit includes a main body and a fluorescent powder layer. The main body has a cylindrical outer surface. The fluorescent powder layer is disposed on the cylindrical outer surface. The driving unit is configured to drive the wavelength conversion unit to rotate around an axis. The cylindrical outer surface surrounds the axis. The light source is configured to emit light toward the fluorescent powder layer.

A light-emitting apparatus includes a base, a first semiconductor radiation emitting diode, having a top surface and a side wall, disposed on the base, a transparent structure disposed on the base and surrounding the side wall and covering the top surface, and a phosphor structure placed within the transparent structure surrounding the side wall and covering the top surface. The first semiconductor radiation emitting diode has a width smaller than that of the base and is configured to emit a light which can be converted into a forward transferred down-converted radiation light and a back transferred down-converted radiation light by the phosphor structure. At least a portion of the forward transferred down-converted radiation light and the back transferred down-converted radiation light are emitted toward the base.

A light-emitting apparatus includes a base, a first semiconductor radiation emitting diode, having a top surface and a side wall, disposed on the base, a transparent structure disposed on the base and surrounding the side wall and covering the top surface, and a phosphor structure placed within the transparent structure surrounding the side wall and covering the top surface. The first semiconductor radiation emitting diode has a width smaller than that of the base and is configured to emit a light which can be converted into a forward transferred down-converted radiation light and a back transferred down-converted radiation light by the phosphor structure. At least a portion of the forward transferred down-converted radiation light and the back transferred down-converted radiation light are emitted toward the base.

A light source device includes a semiconductor light-emitting device which emits coherent excitation light, and a wavelength conversion element which is spaced from the semiconductor light-emitting device, generates fluorescence by converting the wavelength of the excitation light emitted from semiconductor light-emitting device, and generates scattered light by scattering the excitation light. The wavelength conversion element includes a support member, and a wavelength converter disposed on the support member. The wavelength converter includes a first wavelength converter, and a second wavelength converter which is disposed around the first wavelength converter to surround the first wavelength converter in a top view of the surface of the support member on which the wavelength converter is disposed. The ratio of the intensity of fluorescence to that of scattered light is lower in the second wavelength converter than in the first wavelength converter.

A light source device includes a semiconductor light-emitting device which emits coherent excitation light, and a wavelength conversion element which is spaced from the semiconductor light-emitting device, generates fluorescence by converting the wavelength of the excitation light emitted from semiconductor light-emitting device, and generates scattered light by scattering the excitation light. The wavelength conversion element includes a support member, and a wavelength converter disposed on the support member. The wavelength converter includes a first wavelength converter, and a second wavelength converter which is disposed around the first wavelength converter to surround the first wavelength converter in a top view of the surface of the support member on which the wavelength converter is disposed. The ratio of the intensity of fluorescence to that of scattered light is lower in the second wavelength converter than in the first wavelength converter.

An emitter, in particular a lamp, and a method for emitting light are described. The emitter comprises at least one LED element for producing electromagnetic radiation in a first frequency range and an active cooling unit for cooling the at least one LED element, having at least one cooling channel for a coolant. The at least one cooling channel is arranged at least partially in a beam path of the electromagnetic radiation produced by the at least one LED element. The coolant comprises at least one phosphor for converting at least a part of the electromagnetic radiation into light to be emitted in a second frequency range, which is different from the first frequency range.

An emitter, in particular a lamp, and a method for emitting light are described. The emitter comprises at least one LED element for producing electromagnetic radiation in a first frequency range and an active cooling unit for cooling the at least one LED element, having at least one cooling channel for a coolant. The at least one cooling channel is arranged at least partially in a beam path of the electromagnetic radiation produced by the at least one LED element. The coolant comprises at least one phosphor for converting at least a part of the electromagnetic radiation into light to be emitted in a second frequency range, which is different from the first frequency range.