Physics 145 Introduction to Experimental Physics I Instructor: Karine Chesnel Office: N319 ESC Tel: Office hours: on appointment Class website:

Lab space availability Wednesday 3 – 6 pm: 3 seats Thursday 8 – 11 am: 1 seat Thursday 11 am– 2 pm: 1 seat Thursday 3 – 6 pm: - Friday 11am – 2 pm: 9 seats Friday 2 – 5 pm: -

Your lab assignments 1.Prepare by reading the introduction material 2.Answer quiz questions (within the first half hour) and submit the sheet to your TA 3.Proceed to the experiments: L2.1, L2.2, etc… 4.Write a report of your findings for each experiment, in your lab notebook (individual reports)

Lab 3 Interference Diffraction

Interferences Constructive interference Destructive interference Adding waves: Difference in optical path: constructive destructive

Interferences & diffraction Single slit Diffraction pattern

Interferences & diffraction Double slits Diffraction pattern

Interferences & diffraction Double slits Peak separation Slits separation Envelope width (separation between maxima) Slits width

Interferences & diffraction Double slits Single slit

Interferences & diffraction Double slits Five slits

Interferences & diffraction Grating Zero order first order second order

Lab 3: Interference & Diffraction A. Alignment L3. 1: Vertical alignment (posts) L3.2: Horizontal alignment (bench) L3.3: Lenses positioning (collimation, focalization) L3.4: Source – eyepiece alignment

B. Qualitative observations L3.5: Green filter – Single slit, varying size L3.6: Try different filters, optimize color L3.7: Double-slits, varying spacing L3.8: Grating: compare intensity, resolution C. Quantitative measurement L3.9: Use diffraction pattern from the grating to determine the wavelength of the light Lab 2: spectroscopy