Question 3: Reflection and Absorption You plan to use a thin single crystalline silicon sheet to partially attenuate the light intensity of your laser beams. You found the following two tables providing the information you need. Please answer the following questions. Absorption Coefficient of Silicon real and imaginary refractive index of silicon 1E07 8 LE00 i 1E0% - % 7 - LEsO4 t h 1E-03 | 6 I = 1E02 P 3 c T 5 ' L g 160 { e - L Real 1E01 t 1 v 3] 1m e L | % | , L B a0 y ] \\ % 1LE04 { | 2 LEOS | | \\ 1646 - ' ) 1 Imaginar 1E07 : \\ g y 1608 0 1 e 200 300 400 S00 00 700 800 900 1000 1100 1200 1300 1400 200 300 400 0D GO0 700 800 900 1000 1100 1200 1300 1300 wavelength (nm) wavelength {nm) (1) If your laser beam has a wavelength of 1250nm (in vacuum) and a power of 1 mW, and the thickness of the silicon sheet is 500 um, how much laser power is reflected at the first air-silicon interface (assume normal incident) (5 pts) (2) How much laser power can penetrate across this silicon wafer to the other side of the wafer? (5 pts) (3) What is the wavelength of the laser inside silicon? (5 pts) (4) If you change your laser wavelength to 400nm (in vacuum), what is the penetration depth into the silicon wafer? (5 pts) Laser beam A=1250 nm Power: 1 mwW Air I Thickness: 500 um