High efficiency emitter for incandescent light sources

An emitter for incandescent light sources, capable of being brought to incandescence by means of-passage of electric current, wherein on at least one surface of the emitter (F) a micro-structure (R) is provided, operative to enhance absorbance for wavelengths belonging to the visible region of the spectrum, characterized in that

• said micro-structure (R) is at least partly made of a material (Au) whose melting temperature is lower than the operating temperature of the emitter (F), and
• at least a substantial portion of the emitter (F), including said micro-structure (R), is coated with an oxide with high melting point (OR), such as a refractory oxide,
• said oxide being operative to preserve a profile of said microstructure (R) in case of deformation or change of state of the respective material (Au), consequent to the use of the emitter (F) at an operating temperature exceeding the melting temperature of said material (Au).

A method for constructing an emitter capable of being brought to incandescence by the passage of electric current, comprising the steps of:

• obtaining a filiform or laminar element of the material whereof the emitter is to be made (F), said material (Au) having a melting temperature lower than the operating temperature at which the emitter (F) is meant to be used;
• etching said element to form an anti-reflection micro-structure (R),
• and coating the emitter (F) in which the anti-reflection micro-structure (R) has been formed with a refractory oxide (OR), said oxide being operative to preserve a profile of said microstructure (R) in case of deformation or change of state of the respective material (Au), consequent to the use of the emitter (F) at an operating temperature exceeding the melting temperature of said material (Au).