Antenna system and uses thereof

1. An antenna system, comprising a first end-fire antenna element and a second end-fire antenna element facing each other in a planar arrangement, said antenna elements having a thickness which is larger than a skin depth of a material forming said antenna elements, said antenna elements being positioned to form one or more air gaps therebetween, and being configured to cause destructive interference between individual end-fire radiations of said elements, while maintaining constructive interference generally perpendicular to said planar arrangement.

2. The system of claim 1 , wherein said first end-fire antenna element is identical to said second end-fire antenna.

3. The system according to claim 1 , wherein each of said antenna elements is a slot antenna element having a tapered profile.

4. The system according to claim 3 , wherein said tapered profile is characterized by an opening rate selected such that a ratio between an imaginary part and a real part of an impedance of said antenna system is less than 50%.

5. The system according to claim 4 , wherein said opening rate is from about 0.0001 to about 0.01 nm −1 .

6. The system according to claim 3 , wherein each slot has a stub and an aperture and is symmetric with respect to a meridian line connecting said stub and aperture, perpendicularly to said aperture.

7. The system according to claim 3 , wherein each slot has a stub and an aperture and is asymmetric with respect to a meridian line connecting said stub and aperture, perpendicularly to said aperture.

8. The system according to claim 1 , wherein each of said antenna elements is a Vivaldi antenna element.

9. The system according to claim 1 , wherein a thickness of said antenna elements is at least 2 times said skin depth.

10. The system according to claim 1 , wherein a width of said gap is selected so as to allow emission of radiation in a transverse optical mode while suppressing higher optical modes.

11. The system according to claim 1 , wherein a width of said gap is at least 10 nm.

12. The system according to claim 1 , further comprising a waveguide coupled to said gap.

13. The system according to claim 12 , wherein said waveguide is a parallel plate waveguide.

14. The system according to claim 1 , wherein at least one of said first and said second end-fire antenna elements has a nanometric size along at least one dimension of said element.

15. The system according to claim 1 , wherein at least one of said first and said second end-fire antenna elements has a nanometric size along a largest dimension of said element.

16. An antenna array, comprising a plurality of antenna systems according to claim 1 .

17. The array according to claim 16 , wherein at least a portion of said antenna systems are connected in series with respect to a characteristic direction of said end-fire radiations.

18. The array according to claim 16 , wherein at least a portion of said antenna systems are connected in parallel with respect to a characteristic direction of said end-fire radiations.

19. The array according to claim 16 , wherein said antenna systems are connected via DC connection.

20. A method of detecting electromagnetic radiation, comprising generating condition for the radiation to interact with the antenna system or array according to claim 1 , and collecting electrical signals generated by said antenna system.

21. The method according to claim 20 , wherein said electromagnetic radiation comprises radiation in the infrared range.

22. The method according to claim 20 , wherein said electromagnetic radiation comprises radiation in the visible range.

23. A method of emitting electromagnetic radiation, comprising applying voltage to the antenna system or array according to claim 1 , thereby generating the electromagnetic radiation.

24. A method of converting electromagnetic radiation into electricity, comprising generating condition for the radiation to interact with the antenna system or array according to claim 1 , and collecting electrical signals generated by said antenna system.

25. A system, comprising the antenna system or array according to claim 1 , wherein the system is selected from the group consisting of an optical sensor system, optical communication system, an imaging system, a light projector, a high harmonics generating system, a wave mixing system, a frequency conversion system, and a phased array.

26. The method according to claim 1 , wherein said antenna elements comprise metal.