Near-infrared hybrid lens systems with wide field of view
A near-infrared hybrid lens system for imaging a wide field-of-view scene onto an image plane includes (a) a first cast lens positioned closest to the scene and at least partly transmissive to near-infrared light, (b) a second cast lens positioned closest to the image plane and at least partly transmissive to near-infrared light, and (c) a wafer-level lens at least partly transmissive to near-infrared light and disposed between the first cast lens and the second cast lens, wherein the wafer-level lens has (i) a planar substrate with a first surface facing away from the image plane and a second surface facing the image plane, (ii) a first lens element disposed on the first surface, and (iii) a second lens element disposed on the second surface.
1. A near-infrared hybrid lens system for imaging a wide field-of-view scene onto an image plane, comprising:
a first cast lens positioned closest to the scene and at least partly transmissive to near-infrared light;
a second cast lens positioned closest to the image plane and at least partly transmissive to near-infrared light; and
a wafer-level lens at least partly transmissive to near-infrared light and disposed between the first cast lens and the second cast lens, the wafer-level lens including
(a) a planar substrate having a first surface facing away from the image plane and a second surface facing the image plane,
(b) a first lens element disposed on the first surface, and
(c) a second lens element disposed on the second surface;
wherein the first lens element and the second lens element are of a first material that is different from material of each of the first cast lens and the second cast lens.
2. The near-infrared hybrid lens system of claim 1 , each of the first cast lens, the wafer-level lens, and the second cast lens being at least partly transmissive to light in wavelength range from 825 to 875 nanometers.
3. The near-infrared hybrid lens system of claim 1 , the second cast lens having smaller diameter than image circle diameter of the near-infrared hybrid lens system, each of the first cast lens and the wafer-level lens having smaller diameter than the second cast lens.
4. The near-infrared hybrid lens system of claim 1 , the first cast lens having a convex surface facing away from the image plane and a concave surface facing the image plane.
5. The near-infrared hybrid lens system of claim 4 , each of the convex surface and the concave surface being spherical.
6. The near-infrared hybrid lens system of claim 1 , the first lens element having a convex surface facing away from the image plane, the second lens element having a convex surface facing the image plane.
7. The near-infrared hybrid lens system of claim 1 , the second cast lens being gull-wing shaped.
8. The near-infrared hybrid lens system of claim 7 , the second cast lens having a first lens surface facing away from the image plane and a second lens surface facing the image plane, the first lens surface being convex at optical axis of the near-infrared hybrid lens system, the second lens surface being concave at the optical axis.
9. The near-infrared hybrid lens system of claim 8 ,
the first cast lens having a convex surface facing away from the image plane and a concave surface facing the image plane;
the first lens element having a convex surface facing away from the image plane; and
the second lens element having a convex surface facing the image plane.
10. The near-infrared hybrid lens system of claim 1 , the first cast lens having Abbe number greater than Abbe number of each of the second cast lens, the first lens element, and the second lens element.
11. The near-infrared hybrid lens system of claim 10 , Abbe number of the second cast lens being smaller than Abbe number of each of the first lens element and the second lens element.
12. The near-infrared hybrid lens system of claim 1 ,
the first cast lens having an S2 lens surface facing the image plane, the S2 lens surface having radius of curvature R 2 ;
the first lens element having an S3 lens surface facing away from the image plane, the S3 lens surface having radius of curvature R 3 ;
the second lens element having an S4 lens surface facing the image plane, the S4 lens surface having radius of curvature R 4 ; and
the second cast lens having an S6 lens surface facing the image plane, the S6 lens surface having radius of curvature R 6 ;
wherein −1.4>R 4 /R 2 >−2.5, −0.9>R 3 /R 4 >−1.55, and −0.95>R 4 /R 6 >−1.5.
13. The near-infrared hybrid lens system of claim 1 , having field of view angle of 140°.
14. The near-infrared, hybrid lens system of claim 13 , having working F-number less than 2.2.
15. The near-infrared hybrid lens system of claim 13 , having image circle (IC) and total track length (TTL) such that TTL/IC<1.1.
16. The near-infrared hybrid lens system of claim 15 , having TTL<3.0 millimeters.
17. The near-infrared hybrid lens system of claim 16 , each of the first cast lens, the wafer-level lens, and the second cast lens having diameter less than 2.0 millimeters.
18. The near-infrared hybrid lens system of claim 17 , the second cast lens having greater diameter than each of the first cast lens and the wafer-level lens.