405nm - Blu-ray Forum

shatta · 11-30-2007, 02:49 PM

blu ray and hd dvd format relies on the 405 nm blue-violet laser diodes...why does blu ray hold more than hd-dvd...is it the material they used for the disc ..let me in

welwynnick · 11-30-2007, 02:52 PM

The difference is that Blu-ray has a pick-up with a larger numerical aperture.

In other words, the lens that focusses the laser on the track is bigger, and can focus the beam onto a smaller spot. The significance of size is that smaller lenses suffer from diffraction effects - it's just laws of physics.

(Though there will be ways round them in the future!)

Nick

WickyWoo · 11-30-2007, 03:07 PM

Quote:

(Though there will be ways round them in the future!)

But only in red for now

CptGreedle · 11-30-2007, 03:18 PM

CptGreedle · 11-30-2007, 03:19 PM

The data is stored in a finer fashion, with a more advanced system. The HD-DVD system uses the same set up for burning the discs as a DVD. But the BD is all new so it is capable of so much more.
The hard ware is capable of much more such as bandwidth as well.

CptGreedle · 11-30-2007, 03:21 PM

Hitachi and other companies are working on a 100 GB model and a 200 GB model that will have higher apertures and also more layers.
It would wok exactly the same as existing BDs, just with more storage. So no pauses during layer changes, etc.

11-30-2007, 02:49 PM	#1
shatta Expert Member Member since:Jun 2007 Location:New York	405nm blu ray and hd dvd format relies on the 405 nm blue-violet laser diodes...why does blu ray hold more than hd-dvd...is it the material they used for the disc ..let me in

11-30-2007, 02:52 PM	#2
welwynnick Senior Member Member since:Sep 2007	The difference is that Blu-ray has a pick-up with a larger numerical aperture. In other words, the lens that focusses the laser on the track is bigger, and can focus the beam onto a smaller spot. The significance of size is that smaller lenses suffer from diffraction effects - it's just laws of physics. (Though there will be ways round them in the future!) Nick Last edited by welwynnick; 11-30-2007 at 02:54 PM.

11-30-2007, 03:18 PM	#4
CptGreedle Blu-ray Ninja Member since:Jul 2007 Location:Sworn super-hero now services Atlanta (and suburbs). Blu-ray collection:128 Blu-ray reviews:5

11-30-2007, 03:19 PM	#5
CptGreedle Blu-ray Ninja Member since:Jul 2007 Location:Sworn super-hero now services Atlanta (and suburbs). Blu-ray collection:128 Blu-ray reviews:5	The data is stored in a finer fashion, with a more advanced system. The HD-DVD system uses the same set up for burning the discs as a DVD. But the BD is all new so it is capable of so much more. The hard ware is capable of much more such as bandwidth as well.

11-30-2007, 03:21 PM	#6
CptGreedle Blu-ray Ninja Member since:Jul 2007 Location:Sworn super-hero now services Atlanta (and suburbs). Blu-ray collection:128 Blu-ray reviews:5	Hitachi and other companies are working on a 100 GB model and a 200 GB model that will have higher apertures and also more layers. It would wok exactly the same as existing BDs, just with more storage. So no pauses during layer changes, etc.

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