ToughSTEM
Sign Up
Log In
ToughSTEM
A question answer community on a mission
to share Solutions for all STEM major Problems.
Cant find a problem on ToughSTEM?
0
Go to
http://phet.colorado.edu/simulations/sims.php?sim=Wave_Interference
and click on Run Now. 
 1) CD basic: Diffraction effects on pit size.
As you'll see, changing the pit size also changes signal clarity.
Change the slit size to 790, but leave the other variables (slit position and slit separation) the same. Draw your screen results for both red and blue light. Then change your slit width to 260, and do the same.
Which color of light is less likely to have data errors with small data encryption regions (in this case slits' or in the case of actual CDs, which work by reflection, pits)?
What is the advantage of having smaller regions for data encryption on a CD or DVD?
What is a Blu-Ray DVD?   (If you aren't sure, look at http://www.blu-ray.com/info/ . )
Can you play a Blu-Ray DVD on a first generation DVD player? Explain.
Can you play a DVD designed for original 1st generation players on a Blu-ray DVD player? Explain.
Edit
Added Wed, 08 Jul '15
Community
1
Comment
Add a Comment
Solutions
0
Blu-ray (not Blue-ray) also known as Blu-ray Disc (BD), is the name of a new optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. This extra capacity combined with the use of advanced video and audio codecs will offer consumers an unprecedented HD experience

1st Generation ... The first blue laser diode was developed in 1996 by Shuji Nakamura, ... Of course you can put this on a single DVD, but if this trend follows over the years ... It could be pretty cool that you could run your website by using a pc.

The true advantage of using blue light over red light is that well-aligned CD and DVD players actually focus the laser beam such that only one pit is illuminated (eliminating any chance of optical reading errors, because as we've seen, illumination of more than one region more easily leads to errors). Unfortunately, the size of the focus is itself diffraction-limited, which means that the wavelength of light determines the size of the focal spot. Blue light, which diffracts less, makes a smaller focal spot than red light, so it more easily will illuminate just one region when the region of data encryption is smaller. With smaller data regions per bit of information, more data can put encrypted on a given disc size.

As you'll see, changing the pit size also changes signal clarity.

Change the slit size to 790, but leave the other variables (slit position and slit separation) the same. Draw your screen results for both red and blue light. Then change your slit width to 260, and do the same. Screen charts are provided for this below.

Blue light signal:        Red light signal:         Blue light signal:        Red light

blue color of light is less likely to have data errors with small data encryption regions.
Edit
Added Wed, 08 Jul '15
Community
1
Comment
Add a Comment
Add Your Solution!
Close

Click here to
Choose An Image
or
Get image from URL
GO
Close
Back
Add Image
Close
What URL would you like to link?
GO
α
β
γ
δ
ϵ
ε
η
ϑ
λ
μ
π
ρ
σ
τ
φ
ψ
ω
Γ
Δ
Θ
Λ
Π
Σ
Φ
Ω
Copied to Clipboard

Add Your Solution
Sign Up
to interact with the community. (That's part of how we ensure only good content gets on ToughSTEM)
OR
OR
ToughSTEM is completely free, and its staying that way. Students pay way too much already.
Almost done!
Please check your email to finish creating your account!
Welcome to the Club!
Choose a new Display Name
Only letters, numbers, spaces, dashes, and underscores, are allowed. Can not be blank.
Great! You're all set, .
A question answer community on a mission
to share Solutions for all STEM major Problems.
Why
The Purpose
How
The Community
Give Feedback
Tell us suggestions, ideas, and any bugs you find. Help make ToughSTEM even better.