1. Trivia Question Which “Big Bang Theory” character is from New Jersey? (a) Raj Koothrappali (b) Bernadette Rostenkowski (c) Howard Wolowitz (d) Sheldon Cooper (e) Amy Farrah Fowler (f) Leonard Hofstadter (g) Penny d c a e b f g

2. Lab 7 layout

3. The Electromagnetic Spectrum

4. Is RED or BLUE easier to see at Night? During day?

5. Photometric versus Radiometric Units For detection by human eye, there is a ‘conversion factor’ to convert Radiometric units (eg. Watts) to Photometric units (eg. Lumens)

6. Example Problem Consider a point source of light with a total power of 1.0W (a)What is the intensity of the light 2m away from source? (b) If a detector with an active area of 5x5mm is used to detect the light, what is the total power incident on the detector 2m from source? (c)How does your answer to be (b) change if the detector is oriented at an angle? (d)If the sensitivity of the detector is 10 3 V/W, what voltage does the detector generate? (e)With the light source blocked, the measured voltage output on the detector (due to noise) is 10 -6 V. Is the point light source of (d) detectable?

7. Example Problem Using a laser with Wavelength=633nm, beam diameter of 4mm, and total power of 1mW. (a)Assume light is centered on a 10 by 10mm detector. How much power is incident on the detector? (b)If sensitivity is 103 V/W, what is the voltage output of the sensor? (c)If the detector is 5mm by 5mm what is the power on the detector and the detector voltage? (d)If the detector is 1mm by 1mm what is the detected power and voltage?

8. Lab 7 layout