Laser Output

[Myauk]

While preparing Specifications for DVD Recorder sets, I noticed that
they are in a range from 0.8 mW to 1.2 mW for Laser output power
during reading, and from 20 mW to 78 mW for Output Power During
writing.
And also the Laser Wavelength is different form one another 650, 658,
780, 785 etc.
I thought they should follow the standard value which might be the
same for all the DVD Recording units selling in the market.
Any comments?

 

[D from BC]

While preparing Specifications for DVD Recorder sets, I noticed that
they are in a range from 0.8 mW to 1.2 mW for Laser output power
during reading, and from 20 mW to 78 mW for Output Power During
writing.
And also the Laser Wavelength is different form one another 650, 658,
780, 785 etc.
I thought they should follow the standard value which might be the
same for all the DVD Recording units selling in the market.
Any comments?

All I know is that I think I saw a youtube video of someone igniting a
match with a DVD laser...
D from BC

 

[Jim Yanik]

All I know is that I think I saw a youtube video of someone igniting a
match with a DVD laser...
D from BC

Why would DVD's take so much power to write? Do CD's need that much power?

also,shorter wavelength means more data can be written.

 

[Myauk]

 

[Myauk]

And also the Laser Wavelength is different form one another 650, 658,

780, 785 etc.

(nano meter range)

 

[Rene Tschaggelar]

Why would DVD's take so much power to write? Do CD's need that much power?

I'd expect the power to be proportional to the datarate
and we're not slow anymore, the movies would never get written.

Rene

 

[Myauk]

Does anybody know the standard figures for them?
I mean, is there any standard for this?
Regards