1 / 17

Lecture 18 Ray Optics-4 Chapter 23

Lecture 18 Ray Optics-4 Chapter 23. PHYSICS 270 Dennis Papadopoulos March 24, 2010. Convex Mirror. Virtual Image – Rays Diverge. Tactics: Ray tracing for a spherical mirror. Tactics: Ray tracing for a spherical mirror. Optical axis. A parallel ray reflects through focal point

chinue
Download Presentation

Lecture 18 Ray Optics-4 Chapter 23

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Lecture 18Ray Optics-4 Chapter 23 PHYSICS 270 Dennis Papadopoulos March 24, 2010

  2. Convex Mirror Virtual Image – Rays Diverge

  3. Tactics: Ray tracing for a spherical mirror

  4. Tactics: Ray tracing for a spherical mirror

  5. Optical axis • A parallel ray reflects through focal point • A ray through the focal point reflects parallel to the axis • A ray striking the mirror center reflects at an equal angle on the opposite side of the axis

  6. Tactics: Ray tracing for a spherical mirror

  7. A Little Math

  8. Take rays near axis, paraxial rays The excess time along OP vs. OQ is h2/2s and the excess time on the PO’ route vs. QO’ is n(h2/2s’). This is compensated by the delay time from V to Q (Notice that we took the VQ distance as traveled at c). This delay time is (n-1)VQ. For a spherical surface with radius R, VQ=h2/2R. We thus have See equ. 23.21 of the book with n1=1, n2=n

  9. Details of mathematical proof h These are the excess time along OP and along PO’ if we assume that the distance VQ is covered at speed at the vacuum speed c and not v. In other words the time to go from V to Q is not as it was straight in vacuum but slower by the factor v/c. So the excess delay is then Q For light to arrive at the same time travelling the path OVO’ and the path OPO’ we must have Where VQ= h2/2R

  10. A paraxial ray • moves in a parabolic path. • is a ray that has been reflected from parabolic mirror. • is a ray that moves nearly parallel to the optical axis. • is a ray that moves exactly parallel to the optical axis.

  11. A paraxial ray • moves in a parabolic path. • is a ray that has been reflected from parabolic mirror. • is a ray that moves nearly parallel to the optical axis. • is a ray that moves exactly parallel to the optical axis.

  12. The Mirror Equation For a spherical mirror with negligible thickness, the object and image distances are related by where the focal length f is related to the mirror’s radius of curvature by

  13. What is specular reflection? • The image of a specimen. • A reflection that separates different colors. • Reflection by a flat smooth object. • When the image is virtual and special.

  14. What is specular reflection? • The image of a specimen. • A reflection that separates different colors. • Reflection by a flat smooth object. • When the image is virtual and special.

  15. A virtual image is • the cause of optical illusions. • a point from which rays appear to diverge. • an image that only seems to exist. • the image that is left in space after you remove a viewing screen.

  16. A virtual image is • the cause of optical illusions. • a point from which rays appear to diverge. • an image that only seems to exist. • the image that is left in space after you remove a viewing screen.

More Related