Radiation emitting element and a method of providing it

A radiation emitting element comprising:

• a radiation transmissive element having a first refractive index, a first surface and a second, opposite surface;
• a radiation emitter adapted to emit radiation of a first wavelength into the radiation transmissive element;
• and
• a plurality of radiation controlling elements, wherein each radiation controlling element comprises,
• a first liquid having a second refractive index, the first liquid having a transmittance of at least 10% at the first wavelength,
• a second fluid having a third refractive index being lower than the second refractive index, the second refractive index being closer to the first refractive index than the third refractive index,
• a covering element abutting the first surface, being positioned adjacent to a first surface part of the first surface, having a fourth refractive index being lower than the first refractive index and supporting Total Internal Reflection (TIR) transport of the radiation within the transmissive element, and being transmissive to the radiation, and
• a means for altering a shape of the first liquid between two modes wherein,
• in a first mode, the first liquid being in contact with the first surface at the first surface part, and an interface between the first liquid and the second fluid, at the first surface part, is not parallel to the first surface part, and
• in a second mode, a surface of the second fluid, at the first surface part, is at least substantially parallel to the first surface part, and at least part of the first liquid overlaps the covering element.