# Wave and Optics help

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1. Sep 27, 2014

### Zaheer

1. Consider a y-polarized electromagnetic wave with vacuum wavelength 600nm that is propagating in glass and then incident on a glass-air interface; use n=1.4 for glass. Take the interface surface to be the y-z plane, and the plane of incidence to be the x-z plane. Consider 2 incident angles, 45, and 80 degrees. Take the amplitude of the incident field to be Eo.

Write complete expressions for the reflected and transmitted electric fields If there are any evanescent fields, determine the depth of penetration into air.

2. Relevant equations
I've determined the E-field to be perpendicular to the plane of incidence so
r(perpendicular)= (E0r/E0i)= (nicos(thetai)-ntcos(thetat))/nicos(thetai)+ntcos(thetat)
then snells law nisin(thetai)=ntsin(thetat)
Then Possibly the O.P.L= INtegral from S to P n(s)ds
OPL/lamda0=s/lamda
t=OPL/c
where OPL is the Optical path length, n(s) is the index of refraction incident as a function of position.
3. The attempt at a solution
Okay, so I began with attempting to solve for the reflected E-field. So I first used Case 1 where thetai= 45. I solved for theta t, and got 30.3 degrees. then solved for the reflected amplitude and got -o.5016 (obtained by plugging in values to the E0r equation. So I wrote the Reflectance to be the following

r(perpendicualar)= -0.5016/Eo. I dont think thats right at all due to the fact that it should also refract in glass, then reflect so off air, and refract in air, I only took the case where it relfects of glass. Im almost completley stuck, tried reviewing sections to try and understand this problem better but havent been able to. Could anyone just help shoot me in the right direction please? Thanks.

2. Sep 27, 2014

### Zaheer

bump, really needing help plz

3. Sep 27, 2014

### Zaheer

HELPPPPPPPP
AHHHH

4. Sep 28, 2014

### Zaheer

BUMP

5. Sep 29, 2014

### Zaheer

HOLY bump again. At this point ive done the problem. I just want some reassurance.

6. Feb 13, 2015

### mgn321

Hi Zaheer could you please respond to my messege I believe you must have been taking phy2311 at uottawa, because I had been searching for answers to the assignments and usually come across your posts, could you please write back to me if you find a minute I have a question from you. Thank you in advance.