Interference and wavelength of laser light lab conclusion

Interference & Diffraction of Light: The Wave Theory EXPERIMENTAL PROCEDURES PART 1: MEASURING THE WAVELENGTH OF LIGHT The diffraction grating you are using has 6000 slits per centimeter etched into it. Therefore, the spacing between adjacent slits is d= 1 cm = 1.667  10 −4 cm . 6000 (6) (Don't forget that 1 centimeter equals 1/100 of a meter!) The results of the following experiment should be recorded on Data Table 1. Answer all questions below as part of your Lab Report. PROCEDURE 1. Pass the laser beam through the diffraction grating. Do you see a sharp central bright spot, surrounded by a series of off-central bright spots? Use the metric ruler mounted on the screen to carefully measure y1st bright. Then calculate the wavelength λ of the laser light. 2. Measure carefully the distance L between the diffraction grating and the screen. 3. Carefully measure y2nd bright and again calculate the wavelength λ of the laser light. 1 Interference & Diffraction of Light: The Wave Theory PART 2: PREDICTING POSITION OF AN INTERFERENCE PATTERN In this exercise you will calculate the position for a second order diffraction pattern (y2nd bright) produced from green laser light. For this calculation, equation 5 has to be solved for yn. Doing some algebra shows that equation 5 can be rewritten as: yn = nL d − (n ) 2 2 (7) The results of the following experiment should be recorded on Data Table 2. PROCEDURE 1. The green laser emits at a 532nm wavelength. Set your L to a reasonable distance and calculate y2nd bright using equation 7. Do your calculation in the space provided below Data Table 2. 2. Show the result to your T.A. Once your T.A. approves, you can continue the experiment to verify your result with the green laser. Make sure the distance L between the grating and the screen is the same value you chose in your calculation. Shine the laser through the grating and onto the screen. 3. Record the position of the n = 2 green spot. Compare it with your calculation. 2 Interference & Diffraction of Light: The Wave Theory PART 3: INTERFERENCE PATTERN OF WHITE LIGHT White light (e.g. light from an ordinary incandescent light bulb, or from the Sun) is a combination of many colors, i.e. light of many different wavelengths. One way to show this is to pass white light through a prism or a diffraction grating and notice that it becomes separated into its component colors. The prism and the diffraction grating work differently though each separates light into its component colors, and both phenomena are explained by the wave theory of light. The results of the following experiment should be recorded on Data Table 3. PROCEDURE 1. Pass the beam of white light through the diffraction grating. 2. Answer Questions 1 and 2 of the Part 3 Questions section. 3 Interference & Diffraction of Light: The Wave Theory END OF LAB CLEAN UP: Please leave your lab bench as you found it! Thank you! 4 Interference & Diffraction of Light: The Wave Theory INTERFERENCE & DIFFRACTION OF LIGHT: THE WAVE THEORY Name:______________________________________________________ Partner(s):___________________________________________________ Date Performed:______________________________________________ Section Number:______________________________________________ Laboratory Instructor:_________________________________________ 5 Interference & Diffraction of Light: The Wave Theory Grading Attendance: _____ /_______ Quiz: _____ / _______ Lab Exercise: _____ / _______ Clean Up: _____ / _______ Total: _____ / _______ *For TA use only* 6 Interference & Diffraction of Light: The Wave Theory DATA ANALYSIS & QUESTIONS Data Table 1: Red Laser SHOW ALL CALCULATIONS TO GET FULL CREDIT! Distance L: .085 y1st bright: (meters) (meters) λ (calculated from y1st bright): y2nd bright: (meters) (meters) λ (calculated from y2nd bright): (meters) λ average (average of λ1st bright and λ2nd bright): (meters) λ [|actual wavelength – measured average|] (meters) CALCULATIONS: Actual wavelength: 632.8 nm Equation 5: 7 = d  yn n L +y 2 2 n 1 m = 109 nm Interference & Diffraction of Light: The Wave Theory Data Table 2: Green Laser SHOW ALL CALCULATIONS TO GET FULL CREDIT! Distance L: .085 : (meters) n: (meters) d: y2nd bright(calculated from equation 7): (meters) y2nd bright(measured experimentally): (meters) y [|y2nd bright(calculated from equation 7) - y2nd bright(measured)|] = CALCULATIONS: Actual wavelength: 532nm yn = Equation 7: 8 nL d − (n ) 2 2 1 m = 109 nm Interference & Diffraction of Light: The Wave Theory Part 3 Questions 1. Do different colors appear at different places on the screen? Can you explain why this occurs, using your understanding of light as a wave? 2. Is it true that different colors correspond to different wavelengths? Order the visible light color spectrum from the longest wavelength to the shortest wavelength. 9 ...
Purchase answer to see full attachment