On Mon, Mar 18, 2013 at 11:50 AM, Steve Alligood <[email protected]>wrote:
> > On Mar 18, 2013, at 11:18 AM, David Landry wrote: > > > On Mon, Mar 18, 2013 at 10:15 AM, Steve Alligood <[email protected] > >wrote: > > > >> naw, you can get 32+ colors on a pair of single mode fiber, it just > isn't > >> cheap and has problems with different colors at different distances. > >> > > > > Maybe you can, but a single mode waveguide is designed to allow > propagation > > of a single mode at a particular wavelength. That wavelength of that mode > > can be adjusted by changing core diameter and the index of refraction > > profile [0]. > > > > I suppose you could couple other wavelengths into an evanescent mode > along > > the cladding over a short enough distance, though. Are you referring to > > some particular product? > > no, most dwdm and cwdm systems work with multiple colors across SMF. > > I have a set of Cienna chassis with four colors each from Provo to SLC > across a pair of SMF, and a passive WDM system (optics on their own colors, > with a shelf that is basically just a prism combining them) that goes the > same distance across a pair of SMF. > > As far as I know, SMF is the norm for most of my vendor's waves they sell > us across the country. MMF just doesn't make sense for the distances. > > I am not an expert on how they combine, or the issues they have amplifying > the different colors, etc. > Thanks for clarifying. Thinking about it some more, I realized I misspoke. Keeping other things constant, you should be able to transmit wavelengths at least up to the V < 2.4 cutoff (above that, you might still be able to transmit, but it would definitely not be multi-mode anymore). I suppose the hard cutoffs are material-based. > BTW, anyone wanting to know more about fiber, read this: > > > http://www.nanog.org/meetings/nanog48/presentations/Sunday/RAS_opticalnet_N48.pdf +1 Nice set of slides, though I cringed a little where he said that "intensity" and "power" were the same; intensity has units of power per area (e.g. W/m^2). --- David Landry /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
