Lens, laser arrangement and method for producing a laser arrangement
View Patent ↗An aspherical planoconvex lens ( 20 ), containing a material with a refractive index of at least 3.0, in which the height (h) of the convex region ( 21 ) is a maximum of one fifth of the thickness ( 1 ) of the lens ( 20 ). Also disclosed is a laser assembly incorporating such a lens and a method for the manufacture of such a laser assembly.
1. An aspherical planoconvex lens, containing a material with a refractive index of at least 3.0, in which the height of the convex region is a maximum of one fifth of the thickness of the lens.
2. A lens according to claim 1 , where the height of the convex region is a maximum of one eighth of the thickness of the lens.
3. A lens according to claim 1 , where the height of the convex region is between 35 and 60 μm.
4. A lens according to claim 1 , in which the thickness of the lens is between 300 and 500 μm.
5. A lens according to claim 1 , in which the material includes a semiconductor material.
6. A lens according to claim 5 , in which the material includes GaP.
7. A lens according to claim 1 , in which the magnitude of the radius of curvature of the convex region is at least 400 μm.
8. A lens according to claim 1 , in which the numerical aperture is at least 0.7.
9. A lens according to claim 1 , in which at least one radiation entry surface and one radiation exit surface have an antireflection coating.
10. A lens according to claim 9 , in which the antireflection coating contains at least one of the following materials: SiNO, TaO, AlO.
11. A laser assembly, having a semiconductor chip suitable for generating electromagnetic radiation, towards which the plane radiation entry surface of a planoconvex lens according to claim 1 faces in the direction in which radiation is emitted.
12. A laser assembly according to claim 11 , in which the distance between the surface at which radiation is coupled out of the semiconductor chip and the surface where radiation enters the lens is a maximum of 80 μm.
13. A laser assembly according to claim 11 , in which the semiconductor chip is one of the following components: a laser diode chip, laser diode bar.
14. A laser assembly according to claim 11 , in which the semiconductor chip is suitable for generating electromagnetic radiation at a wavelength in the range between 800 and 950 nm.
15. A laser assembly according to claim 11 , in which the lens is fastened to a lead frame by means of adhesive.
16. A laser assembly according to claim 15 , in which the semiconductor chip is fastened to the lead frame by means of a hard solder joint.
17. A method for the manufacture of a laser assembly according to claim 11 , in which a lens is placed within the optical path of a semiconductor chip by means of suction tweezers.
18. A method according to claim 17 , in which the lens is a planoconvex lens.
19. A method according to claim 17 , in which the thickness of the lens is a maximum of 600 μm.
20. A method according to claim 18 , in which the suction tweezers lift the lens on a plane surface, and the lens is placed with a plane surface on the opposite side of the lens onto a carrier.
21. A method according to claim 20 , in which the lens has two plane surfaces on opposite sides that have a length of at least 350 μm in the direction of the optical axis of the lens.