Lighting device, corresponding lamp and method

A lamp comprising:

• a lighting device, said lighting device, comprising:
• an electrically-powered light radiation source,
• a light-permeable body having a longitudinal axis arranged facing said light radiation source for propagating light radiation from said source distally of the light radiation source along said longitudinal axis, the light-permeable body comprising:
• a collimator exposed to said light radiation source for collecting light radiation from said light radiation source and injecting it into said light-permeable body,
• a portion tapered from an input end towards an output end, the input end of said tapered portion coupled to said collimator for receiving light radiation collimated thereby and directing said collimated radiation towards said output end, and
• a distal portion coupled to the output end of said tapered portion,
• the device further comprising an output mirror with a shank portion extending in said distal portion and a head portion, said output mirror reflecting light radiation radially from said longitudinal axis and proximally towards said light radiation source,
• wherein the shank portion extending in the distal portion of said output mirror has a layered dichroic filter structure;
• wherein said layered dichroic filter structure includes a first and a second layer, said first layer having a dichroic filtering surface, wherein light radiation is partially reflected from said first surface and partially propagates through said first layer towards said second layer to be reflected from said second layer;
• and
• a casing for said lighting device, said casing including at least one light-permeable portion for emitting light radiation from said lighting device.

A method of providing a lighting device, the method comprising:

• providing an electrically-powered light radiation source,
• arranging facing said light radiation source a light-permeable body having a longitudinal axis for propagating light radiation from said source distally of the light radiation source along said longitudinal axis, the light-permeable body comprising:
• a collimator exposed to said light radiation source for collecting light radiation from said light radiation source and injecting it into said light-permeable body,
• a portion tapered from an input end towards an output end, the input end of said tapered portion coupled to said collimator for receiving light radiation collimated thereby and directing said collimated radiation towards said output end, and
• a distal portion coupled to the output end of said tapered portion,
• providing an output mirror with a shank portion extending in said distal portion and a head portion, said output mirror reflecting light radiation radially from said longitudinal axis and proximally towards said light radiation source;
• wherein the shank portion extending in the distal portion of said output mirror has a layered dichroic filter structure;
• wherein said layered dichroic filter structure includes a first and a second layer, said first layer having a dichroic filtering surface, wherein light radiation is partially reflected from said first surface and partially propagates through said first layer towards said second layer to be reflected from said second layer.