I don't know of any particular reason why a DVD-player laser should be faster, since neither CD nor DVD players need to deliberately modulate the lasers anyway. At least, that's the first blush answer.
However, these diode lasers are generally noisy, apparently due to the inevitable presence of optical reflections back into the diodes. I once read that deliberately FM'ing the laser by applying a high frequency RF tone along with the DC bias current could be helpful in mitigating the problem. But this was in connection with the *analog* Laser Disk video recording format. I don't know if the laser noise was ever much of a problem with reading the digital formats of CDs and DVDs. If not, then surely the makers of diodes for these mass market applications would not be investing effort in making the lasers fast. On additional factor is that CD players and DVD players use different light wavelengths: ~780 nm for CDs, ~650 nm for DVDs. It might be that the difference in semiconductor composition between the two types makes a significant difference in the response speed. However, I doubt that this would would be relevant for present purposes, unless Rb also has some *useful* transitions in the 650 nm regime. Dana On Thu, Jun 14, 2018 at 11:25 PM, Hal Murray <hmur...@megapathdsl.net> wrote: > > k8yumdoo...@gmail.com said: > > I've been told that CD player type diodes can be successfully modulated > up to > > about 600 MHz, but that going much further is either difficult or perhaps > > impossible. > > Are DVD lasers faster? > > > -- > These are my opinions. I hate spam. > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.