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Photonic Equivalent of "Leakage Current"?

Discussion in 'Electronic Basics' started by Radium, May 18, 2007.

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  1. Radium

    Radium Guest

    Just out of curiosity, lets say [hypothetically], I had a PC that used
    laseronics [photonics using lasers and without any LEDs] in place of
    electronics. If this laseronic computer uses "parallel-Hz" would it
    run into something similar to "leakage current"? If so, what is the
    optical equivalent of leakage current?


  2. contrex

    contrex Guest

    Radium, for whom killfiles were invented!

  3. ADT

    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
  4. Rich Grise

    Rich Grise Guest

    Nobody knows. You'll have to build one and find out!

    Please report back and let us know the results.

    Good Luck!

  5. Erm...

    For me in the meantime it would be enough, when my actual Soundblaster
    Live! Platinum would sound like my AWE64 Gold.
    That new card sounds awfully crap when playing high-end ripped wavs...!
    I don't want to listen the rest of all that bloat ;) (narrow, treble
    encumbered and flat MP3-like sound-quality).

    Kind Regards,

    Daniel Mandic
  6. Bernd Paysan

    Bernd Paysan Guest

    Optical damping. Well, leakage current is unavoidable when you can't turn
    supplies off, because you need it to remember states of flip-flops or such
    like. If you figure out how to have a persistent storage within a
    flip-flop, that doesn't need power, you can avoid leakage by powering up
    the systen only when you need it.
  7. MooseFET

    MooseFET Guest

    That would be "leakage light".

    Since a photon must contain energy and the usual Plank's constant
    applies to it, you can never have your 1Hz machine. You get a 10^15
    Hz machine when you start using light as your clock source. Current
    semiconductor technology is less decades below 10^15Hz than it is
    above 1Hz so you need to consider if it will be lasers or transistors
    that will make the light.

    Using transistors to make the light can have some advantages. If you
    wish to experiment with such ideas, I suggest you scale down in
    frequency and up in the spacial dimensions so that you can use
    macroscopic parts like a 2N2222 and lengths of wire to make the
    radiators. Ironoxide will make your nonlinear magneto-optical
  8. krw

    krw Guest

    Why would a clock necessarily be at the frequency of the light? Is
    the data rate in fiber optics at the frequency (or some integer
    fraction of the frequency) of the light?
  9. MooseFET

    MooseFET Guest

    Remember this is some dream machine we are talking about here. If you
    don't have the clock speed equal to the frequency of the light, you
    are wasting all those edges. Skipping edges on the "clock" doesn't
    count as meeting Radiums goals.
    In nearly every case, a bit on a fiber is carried by many photons[1].
    The exact number of photons varies from bit to bit and the photons are
    not all at exactly the same wavelength. Basically, we have a
    fractional divider situation. Some bits have a different number of
    cycles than others.

    [1] The exceptions are out of the scope of this discussion.
  10. krw

    krw Guest

    I didn't see where he wanted to use every "edge" of the light wave.
    Did I miss that?
    The laser makes them pretty close. Ok, there is some phase noise in
    there. So?
    Nope. This is the Usenet. There is no "scope of the discussion".

    Damn! They're shooting 105s down the road from here and the cat is
    wondering what's going on.
  11. MooseFET

    MooseFET Guest

    You were asking about the number of cycles being an integer or not.
    Since the frequency can't be said to be a constant, it is hard to say
    anything about integer numbers of cycles. The bandwidth of the output
    of a single mode VCSEL is many MHz wide. A multimode one has a
    bandwidth in the GHz.
    Agreed but in terms of both photons and cycles, different bits have
    different numbers of them.

    Ok, so you out smartass remarked me this time. Just wait for next
    time. :)
  12. Radium

    Radium Guest

    Would "leakage light" cause damage to a photonic system in a similar
    manner in which leakage current damages electronic systems.

    Also, I doubt that the clock rate of a photonic system has to be that
    of light. In clock rate, the "Hz" is the number of pulses per second

    "Clock rates are measured in megahertz (MHz), or millions of pulses a

    The clock rate of a CPU is usually determined by the frequency of an
    oscillator crystal.

    So if the crystal gives out on pulse per second, the clock rate is 1

    I could be wrong though.
  13. MooseFET

    MooseFET Guest

    Normally electrical leakage doesn't do any harm. Leakage of light
    wouldn't either.

    Perhaps I didn't understand how you were defining things. If the goal
    is the greatest posible speed for the lowest power, you need to
    consider the energy that is in each photon. This would depend on the

    In actual fact the frequency of the processor is rarely equal to the
    frequency of the crystal. A crystal may be running at 20MHz and the
    processor at 1GHz. The oscillator that runs the processor is kept on
    frequency by referencing it to the 20MHz.
  14. Radium

    Radium Guest

    Doesn't the leakage current cause the system to overheat?
    400 nm wavelength
    So the clock rate and the rate at which the crystal oscillates don't
    match each other? Which frequency is usually higher? What about the
    frequency of one determines the frequency of the other?

  15. Ask an 'Cinema-Technic' expert :)

    Here it is somehow wrong, beside USB, MIDI, Firewire and Wheel Mouse
    Optical :)

    Best regards,

    Daniel Mandic
  16. The effective clock rate is usually higher because it is derived as a
    multiple of the basic crystal oscillation frequency. i.e. the crystal
    is running at 8.33Mhz but the system bus could be clocked at 24x at
    about 200Mhz.
  17. Bob Myers

    Bob Myers Guest

    Absolutely. This is why every electronic device you've
    ever seen turns into a puddle of molten metal and silicon
    within seconds of being turned on.

    But what if I don't like that color?
    And why not? He's earned every penny of it!

    Bob M.
  18. 3

    the answer is always 3.

  19. The answer is still 3 .

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