Overview of the course Principles of geometric optics

1. Overview of the coursePrinciples of geometric optics Physics 123, Spring, 2005 Lecture I

2. Introduction • Instructor Prof. Regina Demina • Office B&L 313 • Phone 275-7357 • Email regina@pas.rochester.edu • Office hour Mon 4-5 pm Lecture I

3. Novosibirsk Lecture I

4. Objective of the course • thorough understanding of the basic physics concepts • ability to use them in applications Lecture I

5. Sources • Text book Physics for Scientists and Engineers, Volume II Third Edition by Douglas C. Giancoli • Class web site /www.pas.rochester.edu/~regina/PHY123 • Lecture notes; • Homework assignments, numeric answers, solutions • Equation sheets for tests, test solutions • Important dates and links Lecture I

6. Solving problems systematically is important. Difference with PHY122: no more workshops recitations Recitations will cover material through the Wednesday lecture. Participation in recitations will count 10% of your final grade. Grade assigned by your TA. Recitations start the week of 1/18, sign up will be open on Thursday 01/13: https://spider.pas.rochester.edu/signup/PHY-123-S05/ Homework is due in recitation class. Homework problems = 10% of your final grade. Recitations and Homework Lecture I

7. One –hour exams • There will be two one-hour exams during the semester. • Both will count. • There will be no makeup exam. • Exams will be given in Wednesday lecture class shown in the schedule. Exam dates are subject to change. I will notify you by email in case of change. • You can bring a calculator, a pencil and a ruler. • 40% of your grade. Lecture I

8. Final Exam • Tuesday, May 3, 8:30 am (sorry!) • Final exam is based on the entire course PHY123. • Last homework will be based on the entire course to give you more time to prepare for the final. It will not be graded. • 30% of the final grade Lecture I

9. Equation sheets • No notes or equation sheets may be brought to exams. • However, a sheet of useful equations will be provided during the test. You can view these sheets in advance, will be linked from course schedule on the web. • Please note that past experience has shown that having equations available does not guarantee success -- understanding is the key. Lecture I

10. Labs • The laboratory is a required and integrated part of the course. • A passing grade in laboratory is required to pass the course: 10% of the grade • Lab manuals and sign up are available on the web: http://web.pas.rochester.edu/~physlabs/home.shtml • See the lab manual for rules and grading procedures. • Start sign up this week (you will be notified by email, but you need to be registered for lab class!!) • Important: There is a short homework (in manuals) due at the beginning of each lab class (even the 1st one!!!) You will not be allowed to start your lab without this homework. Lecture I

11. Grading • Workshops: 10% • Homework: 10% • Hour Exams: 40% • Final Exam: 30% • Laboratory: 10% • Total: 100% • 90% or above: A 88-89.9 – A- 85-87.9 – B+ • 80% - 85% : B 78-79.9 – B- 75-77.9 – C+ • 70% - 75%: C 68-69.9 – C- 65-67.9 – D+ • 60% - 65%: D • Under 60% : F Lecture I

12. Phys 121123 • Phys 121 • how do objects move (kinematics) • Why do objects move (dynamics – forces) • One true (fundamental) force – gravity • First step into the micro world – kinetic theory • Phys 122 • Two more true forces – electricity and magnetism • Unification – EM waves – light • Phys 123 • More detailed study of light • Geometric optics wave properties  particle properties  Quantum mechanics (lasers)  space-time properties • Deeper into the structure of matter – atomic structure • Nuclear structure, elementary particles • Way out in space - cosmology Lecture I

13. Principles of geometric optics Lecture I

14. Concepts • Ray model of light • Image formation • Reflection • Refraction • Dispersion • Total internal reflection Lecture I

15. EM waves • c – speed of light (m/s) • f – frequency (Hz=1/s) • l – wavelength (m) Lecture I

16. Ray model of light • Light is an EM wave diffraction (go around obstacles) • This happens on microscopic scale • In everyday life we use straight line approximation for light propagation = Ray model of light  geometric optics • We infer positions of objects assuming light travels in straight lines. Geometry is important, Bring ruler and pencil, make good pictures!!! Lecture I

17. Reflection • We see objects because • They emit light (Sun, light bulb) • They reflect light (Moon, table) • angle of incidence = angle of reflection: qi=qr Rough surface Polished surface. Lecture I

18. Formation of image No light here  Virtual image • Eye assumes light propagates in straight lines  image (rays of light crossing) is formed behind the mirror • do – distance to object • di – distance to image • For plane mirror do= di If light actually goes through the place where image is formed  real image Lecture I

19. Speed of light in medium • Speed of light in vacuum: c=3.0x108m/s • Speed of light in media: v<c • Index of refraction: n=c/v >1.0 From table 33-1 Vacuum n=1.00 Air n=1.0003 Water n=1.33 Diamond n=2.42 Lecture I

20. Refraction • The front is slowing down Lecture I

21. Refraction, Snell’s law Bend toward normal Bend away from normal Lecture I

22. Image formation • Eye still assumes light propagates in straight lines  optical illusions • Image is shifted • Pool appears shallower Lecture I

23. What if n depends on l? • If n depends on l  angle of refraction depends on l • n(red)<n(green) • A-red, B-green • B- red, A-green A B Dispersion This is why rainbow occurs Lecture I

24. Total internal reflection For q>qc - total internal reflection – no light come out – all light is reflected Fiber optics Necessary condition: from thick to thin media Lecture I

25. 1.3 m 2.1 m 2.7 m x Lecture I