Optical transducer with farfield modifier

1. An optical transducer comprising:

a multi-mode light emitting device formed in a chip, said chip having a light-emitting region, and said light emitting device having an output with an angular spatial intensity distribution that exhibits multiple peaks;

a lens mounted on said chip in front of said light emitting region and in close proximity thereto;

an optical coupling medium coupling said light emitting region to said lens; and

wherein said lens is spaced a distance in the order of a few microns from said light emitting region such that said multiple peaks are reduced to a single peak by said lens.

2. An optical transducer as claimed in claim 1 , wherein said lens is a ball lens.

3. An optical transducer as claimed in claim 2 , wherein said optical coupling medium is a refractive glue.

4. An optical transducer as claimed in claim 3 , wherein said refractive glue has the same refractive index as said ball lens.

5. An optical transducer as claimed in claim 4 , wherein said refractive glue has a different refractive index from said ball lens.

6. An optical transducer as claimed in claim 3 , wherein said refractive glue is silicone.

7. An optical transducer as claimed in claim 2 , wherein said ball lens is mounted on said chip by means of a support integrated onto said chip.

8. An optical transducer as claimed in claim 7 , wherein said support is an annular support.

9. An optical transducer as claimed in claim 7 , wherein said support is made from a material selected from the group consisting of: polyamide, BCB, and photoresist.

10. An optical transducer as claimed in claim 2 , wherein said light emitting device is a VCSEL.

11. An optical transducer as claimed in claim 2 , wherein said light emitting device is formed on a chip, and said ball lens is mounted on a hole etched into said chip.

12. An optical transducer as claimed in claim 2 , wherein said ball lens is made of quartz.

13. An optical transducer as claimed in claim 1 , wherein the diameter of said lens is about 350 mm.

14. A method of modifying the light output of a light emitting device formed in a chip having a light emitting region, said light emitting device having a light output with an angular spatial intensity distribution that exhibits multiple peaks, said method comprising:

mounting a lens on said chip in front of said light emitting region at a distance in the order of a few microns therefrom;

closely coupling said lens to said light emitting device with a refractive glue so and

setting the position of the lens at a distance from said light emitting region such that said lens reduces said multiple peaks to a single peak.

15. A method as claimed in claim 14 , wherein said lens is a ball lens.

16. A method as claimed in claim 15 , wherein said ball lens is made of quartz.

17. A method as claimed in claim 15 , wherein said refractive glue has the same refractive index as said ball lens.

18. A method as claimed in claim 15 , wherein said refractive glue has a different refractive index from said ball lens.

19. A method as claimed in claim 15 , further comprising integrating a support onto said chip, and mounting said ball lens on said support.

20. A method as claimed in claim 19 , wherein said support is formed by high precision lithography.

21. A method as claimed in claim 19 , wherein said support is made of a material selected from the group consisting of: polyamide, BCB, and photoresist.

22. A method as claimed in claim 16 , further comprising etching a recess into said chip over said light emitting region, and mounting said ball lens on said recess.

23. A method as claimed in claim 14 , wherein said refractive glue is silicone.

24. A method as claimed in claim 14 , wherein said light emitting device is a VCSEL.