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Optik Geometri

Handout untuk mata kuliah Optik Geometri bisa didownload disini (Handout Optik Geometri)

Pembiasan dan Pemantulan
Untuk memahami konsep pembiasan dan pemantulan, anda dapat mengamati animasinya disini

Penerapan hukum pembiasan dan pemantulan
Jika suatu sinar datang dari medium dengan indeks bias tinggi menuju medium dengan indeks bias yang lebih rendah, maka akan memungkinkan sinar tersebut tidak mengalami pembiasan dan terpantul secara sempurna didalam medium berindeks bias tinggi tersebut jika sinar datang dengan sudut lebih besar dari sudut kritisnya. Fenomena ini sering disebut dengan Total Internal Reflection (TIR).

Fenomena ini menyebabkan cahaya yang masuk kedalam sebuah berlian (bahan dengan indeks bias tinggi) akan terjebak didalam berlian tersebut sehingga berlian akan terlihat berkilaiuan. Untuk memahami proses bagaimana sebuah berlian terlihat berkilauan, perhatikan gambar dibawah ini :

berlian

pemantulan total pada berlian

Soal Latihan Pembiasan dan pemantulan

1.The wavelength of red helium–neon laser light in air is 632.8nm. (a) What is its frequency? (b) What is its wavelength in glass that has an index of refraction of 1.50? (c) What is its speed in the glass?
2.How many times will the incident beam shown in Figure below be reflected by each of the parallel mirrors?

3.When the light illustrated in Figure below passes through the glass block, it is shifted laterally by the distance d. If n = 1.5, (a) what is the value of d ? (b) find the time required for the light to pass through the glass block!

4.From the figure of prism below, show that
(a).β = r1 + i2
(b).D = i1 + r1 – β
(c).minimum deviation can be achieved if i1 = r2 and r1 + i2

5.A prism that has an apex angle of 50.0° is made of cubic-zirconia, with n = 2.20. What is its angle of minimum deviation?
6.Show that if the apex angle β of a prism is small, an approximate value for the angle of minimum deviation is
7.A glass fiber (n = 1.5) is submerged in water (n = 1.33). What is the critical angle for light to stay in side the optical fiber?
8.Determine the maximum angle  for which the light rays incident on the end of the pipe shown in Figure below are subject to total internal reflection along the walls of the pipe. Assume that the pipe has an index of refraction of 1.36 and the outside medium is air

9.When I was a kid I did a lot of skin diving, and it seemed to me that when a looked down at a fish or shell from out of the water, it was a lot bigger than it was when I brought it up. I decided that the water magnified the image the fish. In fact, the water doesn’t magnify the image, but it does make it appear closer, and theb your brain decides it must be bigger fish (things up close look bigger). Suppose you look almost straight down at an object a distance d below the surface of the water (n = 1.33). How deep does it appear to be?

Referensi :
Fundamentals of Physics – Halliday, Resnick (hal. 1117 – 1120)
Wells D[1].A., H.S.Slusher, M.Browne. Schaum’s Outline of Physics for Engineering and Science (Schaum)

3 responses to “Optik Geometri

  1. Pingback: Soal latihan pembiasan dan pemantulan « PHYSICS FOR FUN

  2. Suwardi Maret 8, 2012 pukul 12:42 am

    Percobaan mengunakan berlian angel pak terus rawan hilang.
    berliankan mahal kalau di jual…………
    Saya numpang pajang muka diblog bapak…..

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