On a second look, it only seems to only map the places above the water.
Though I still suppose it would help you not walk into one by accident... Just in case, like
I remember one of my telecomms lecturers classic stories was that just before colour TVs were being introduced here (Ireland) you could purchase a "black and white to colour TV conversion kit".
This marvel of human ingenuity basically consisted of a piece of acetate dyed blue at the top and green at the bottom.
Guess you could turn it upside down to simulate Australia.
As a footnote he warned us that this would (unfortunately) NOT be taken as a valid answer in the case of an exam question. Having not given this warning previously he'd been forced to award all the smart aleks in the class full marks the year before.
Uhm - I do beg to differ. There is going to be loss at ANY bend, however the minimum bend radius gives to the limit of the acceptable loss.
Now if the light becomes too intense (and 500mW to 1W is a LOT of light in a single mode fibre), the fraction lost in the bend although in itself acceptable, becomes great enough to actually damage the structure of the fibre.
I also wonder how the heating effects the refractive index of the core/cladding itself, and if this might lead to a feedback loss/heating effect.
Just one more note as to why glass fibres are usually single mode, and plastic multimode:
Glass fibres, while extremely low loss (especially in the infrared (1.55 and 1.3 microns)), also tend to be brittle. Thus the standard single mode fibre with these only has about 8 micron core diameter, while a multimode fibre has a core diameter of about 50 microns - half the width of a hair.
Plastic optical fibre (POF), tends to be cheaper and much more flexible, allowing for tighter bends and thicker fibres (~1mm cores). However losses are far higher (especially in the infrared - the standard wavelength of use for PMMA based fibres is 650nm)
Now, single mode fibres are necessary for long distance communication, due to the modal dispersion mentioned in the last post, and again silica is fantastic for this due to its extremely low loss.
However multi-mode is fine for shorter distances, and this is really where POF is really seeing use.
Slashdot Mirror
Perhaps if these jammers were available to the cops it might put a halt to high speed chases of joyriders and ensuing public damage?
On a second look, it only seems to only map the places above the water. Though I still suppose it would help you not walk into one by accident... Just in case, like
...and preventing this
I remember one of my telecomms lecturers classic stories was that just before colour TVs were being introduced here (Ireland) you could purchase a "black and white to colour TV conversion kit".
This marvel of human ingenuity basically consisted of a piece of acetate dyed blue at the top and green at the bottom.
Guess you could turn it upside down to simulate Australia.
As a footnote he warned us that this would (unfortunately) NOT be taken as a valid answer in the case of an exam question. Having not given this warning previously he'd been forced to award all the smart aleks in the class full marks the year before.
Uhm - I do beg to differ. There is going to be loss at ANY bend, however the minimum bend radius gives to the limit of the acceptable loss.
Now if the light becomes too intense (and 500mW to 1W is a LOT of light in a single mode fibre), the fraction lost in the bend although in itself acceptable, becomes great enough to actually damage the structure of the fibre.
I also wonder how the heating effects the refractive index of the core/cladding itself, and if this might lead to a feedback loss/heating effect.
Just one more note as to why glass fibres are usually single mode, and plastic multimode: Glass fibres, while extremely low loss (especially in the infrared (1.55 and 1.3 microns)), also tend to be brittle. Thus the standard single mode fibre with these only has about 8 micron core diameter, while a multimode fibre has a core diameter of about 50 microns - half the width of a hair. Plastic optical fibre (POF), tends to be cheaper and much more flexible, allowing for tighter bends and thicker fibres (~1mm cores). However losses are far higher (especially in the infrared - the standard wavelength of use for PMMA based fibres is 650nm) Now, single mode fibres are necessary for long distance communication, due to the modal dispersion mentioned in the last post, and again silica is fantastic for this due to its extremely low loss. However multi-mode is fine for shorter distances, and this is really where POF is really seeing use.