Register to reply

Dual wavelength modulation

by MS1984
Tags: dual, modulation, wavelength
Share this thread:
MS1984
#1
Sep19-13, 08:50 AM
P: 1
hi

what would happen if i modulated two wavelengths with the same intensity modulation frequency?

for example if i had 2.0um light and 1.5um light and modulated them both with the same frequency, would sidebands develop around each wavelength? or would they interfer in a more complicated way, giving a more complex sideband structure?

thanks, let me know if you need me to clarify this at all
Phys.Org News Partner Physics news on Phys.org
'Comb on a chip' powers new atomic clock design
Quantum leap in lasers brightens future for quantum computing
Enhanced NIST instrument enables high-speed chemical imaging of tissues
mikeph
#2
Sep19-13, 01:08 PM
P: 1,212
Unless you have some nonlinear optical effects I don't see how they would interfere at all. The spectra of each individual modulated signal should just add, no?
Baluncore
#3
Sep20-13, 10:16 AM
Sci Advisor
Thanks
P: 1,714
If the light is amplitude modulated by a sine wave, then each carrier would have a side band on each side. There would be no interaction between those carriers or their sidebands. That is so long as the modulation frequency was not so high that the sidebands overlapped.

This is the same signal scenario as the AM radio band.

meBigGuy
#4
Sep22-13, 02:28 AM
P: 1,072
Dual wavelength modulation

Quote Quote by MS1984 View Post
for example if i had 2.0um light and 1.5um light and modulated them both with the same frequency, would sidebands develop around each wavelength?
Yes, just like any other amplitude modulated signal.

Quote Quote by MS1984 View Post
or would they interfer in a more complicated way, giving a more complex sideband structure?
No, just like any other amplitude modulated signal.

This of course assumes the system is completely linear. The waves cannot interact in a linear system other than interference pattern like effects.


Register to reply

Related Discussions
Modulation Index Dilemma - DSB-LC AM Modulation Engineering, Comp Sci, & Technology Homework 1
Wavelength vs. Frequency Modulation General Physics 2
Frequency/Wavelength-Modulation Spectroscopy - how does it work? Electrical Engineering 6
Dual Side Band Amplitude Modulation Quick Question Electrical Engineering 1
Wavelength modulation/Prism Engineering, Comp Sci, & Technology Homework 3