1. Lenses We will only consider “thin” lenses where the thickness of the lens is small compared to the object and image distances. Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998. http://en.wikipedia.org/wiki/Lens_Maker%27s_Formula

2. Refraction at a Spherical Surface Uses the paraxial approximation Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998. Ingle and Crouch, Spectrochemical Analysis

3. Biconvex Lens: Overlap of two spheres Position of l’: Position of l: Lensmaker’s Formula Ingle and Crouch, Spectrochemical Analysis

4. Convex Concave http://en.wikipedia.org/wiki/Lens_Maker%27s_Formula Basic Lenses

5. Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998. Lens Makers’ Formula Determining the focal length of a lens: If d << R 1, R 2, make the thin lens approximation: f = focal length n = refractive index of lens material n m = refractive index of surrounding medium R 1 = radius of curvature of surface #1 R 2 = radius of curvature of surface #2 d = thickness of lens C R f

6. Simple Lenses Many different configurations: Sign Conventions for R values: C R f Sign of R V left of C + V right of C _ surface is flat ∞ www. wikipedia.org

7. Are you getting the concept? Calculate the focal length of a planoconvex lens of radius of curvature 60 mm and index of refraction of 1.5 in air using the thin lens approximation.

8. Parallel Rays Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.

9. Optical Center Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.

10. Tracing rays to determine the position of the image. Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.

11. Off Axis Rays Focus on the Focal Plane Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.

12. Chromatic Aberrations Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.  is dependent

13. Achromatic Doublet Ingle and Crouch, Spectrochemical Analysis

14. Spherical Aberrations Deviation from the paraxial approximation

15. Field Curvature Image and focal planes are actually spheres Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998.

16. Comatic Aberration (Coma) Axial rays have different optical path lengths in an off-axis system.

17. Comatic Aberration (Coma) Eugene Hecht, Optics, Addison-Wesley, Reading, MA, 1998. Image has a comet-like tail

18. Astigmatism Rays in tangential and saggital planes have different focal points. f t = fcos  1 f s = f / cos  1 Ingle and Crouch, Spectrochemical Analysis

19. Lens Stops ApertureStopFieldStop Ingle and Crouch, Spectrochemical Analysis