2007-01-03 23:18:31 · 4 answers · asked by choudhary_naren 1 in Science & Mathematics ➔ Physics
It can operate, but other frequencies wont fulfil some requirements for long ranges:
1) Pulse spreading (too big dispersion)
2) Loss (absorbtion in material and non-total internal reflection)
3) Some other reasons (that i forgot :) )
2007-01-04 00:07:46 · answer #1 · answered by Saulius B 1 · 0⤊ 0⤋
The reasons we can't go higher are actually pretty complicated.
The first and main reason is the speed at which you can modulate a laser. But this problem has been overcome recently. Still, the 370 Hz is still prety close to the fastest modulation of a laser. Also, the speed at which the detector can operate is important. Finally, when pulses are too short in time, they tend to spread in wavelength (that's not simple: Fourier transform physics)
For the lower limit... Well, that's only a matter of convention. We could go as slow as we want, it's just that we want to send as much information as we want in a short time.
2007-01-04 09:26:58 · answer #2 · answered by Vincent L 3 · 0⤊ 0⤋
The upper limit is due to pulse spreading. Since a fiber cable can be used for an on/off signal, the lower limit may be due to a particular pulse generator.
2007-01-04 07:35:08 · answer #3 · answered by Kes 7 · 0⤊ 0⤋
to operate above or below that range is not possible because that would be a different wavelength.
2007-01-04 07:22:11 · answer #4 · answered by pegasis 5 · 0⤊ 1⤋