why is PHR-803T so powerful??

Hi guys,

I'm just curious why the PHR-803T puts out so much power? First of all it's from a HD-DVD drive rather than a blu-ray drive. Secondly, the drive that it comes from isn't a writer. It only reads discs. So how come it's about 1/3 the power of an 8 x Blu-Ray writer?

Thanks guys.

more like 1/4 - 1/5 of my 8x's

good questions though.. i'd like to know the answer to the second question

http://laserpointerforums.com/f44/finally-i-think-i-may-have-found-answer-28353.html

Here is a thread I made a while, going into the technical aspects of the differences between blu-ray and hd-dvd.

Basically the "dots" the blu-ray burns into a disc are much finer then that of hd-dvd. In essence the beam has a tighter focus which also means less power is required to burn the spot, energy density.

You also have to take into account primitve optics, 803T were the earlier models while the 811 sleds out of the same drives which came later were considerably weaker. This was believed to be primarilly due to better optics, IIRC.

Does anyone know at what power level the diode operates when used in the actual drive?

Another possibility is that laser power capability was not the limiting factor in the speed of the 803 drive platform, but something else. If laser diodes were available that -could- handle more power at good prices, why not install them in the drive and just run them at less then full?

ahhh good explanation you have there brtaman. I think you're probably right. It's the energy density.

However if this theory holds water then wouldn't a CD burner require an enormously powerful diode?

Btw, I wasn't aware that HDDVD used the 0.6mm/0.6mm design just like DVDs.

cyclonite said:

ahhh good explanation you have there brtaman. I think you're probably right. It's the energy density.

However if this theory holds water then wouldn't a CD burner require an enormously powerful diode?

Btw, I wasn't aware that HDDVD used the 0.6mm/0.6mm design just like DVDs.

Click to expand...

They have a very powerful diode, additionally, the energy density does not have to be as high as there is a lower density of the information, and thus the detector has a longer integration time.

cyclonite said:

ahhh good explanation you have there brtaman. I think you're probably right. It's the energy density.

However if this theory holds water then wouldn't a CD burner require an enormously powerful diode?

Btw, I wasn't aware that HDDVD used the 0.6mm/0.6mm design just like DVDs.

Click to expand...

You bring up an interesting point! This is why I love forums. :beer:

However, with HD-DVD as opposed to CD, there is A LOT more data being written in the same time also disk density is much lower. At the same time the film itself could be "easier" to burn? Then again I am sure the earlier CD burners, the ones I was drooling over as kid, that cost as much as a car, were probably also sporting a heavy duty IR diode?

As you said it was more of a theory than anything else. But we also have to take into account that these driver were the beginning of HD-DVD consumer technology, the optics and other factors were definitely not too efficient, the drop in power within the same drive between the two possible sleds colaborates this. I think it is these factors combined that could in some way describe the power of the phr diode.

There have also been theories that the PHR used a HD-DVD burner diode, no one has taken one apart so we cannot compare, from a business stand-piont this theory could be considered feasible.

However, one thing is certain, Blu-ray reader drives (PS3 sled) are generally of much lower power than any HD-DVD reader diode (811, 803), this I believe is due to the energy density.

Hi brtaman,

Indeed it's good to discuss in forums.

By the way you mentioned that HD DVD's 'disc density' is lower? What is the disc density that you're referring to? The strorage density is obviously a lot higher than CD. Are you referring to the material?

Thanks.

Yeah sorry bout that, I was ready to fall asleep when I was writing that post. I meant the opposite in the sense that HD-DVD has a much higher data density on the disc.

hahah cool thanks for clarifying

read this article..

Observations about Blu-Ray lasers - Laser Wiki