Time-domain spectroscopy
analytic technique / From Wikipedia, the free encyclopedia
Time-domain spectroscopy is a type of spectroscopy that measures the power of electromagnetic radiation as a function of time. Normal spectroscopy is frequency-domain spectroscopy. It measures radiation as a function of frequency or wavelength. Time-domain spectroscopy usually requires the use of Fourier transforms.
This article uses too much jargon, which needs explaining or simplifying. (January 2024) |
Two monochromatic lights of different frequencies can combine to show interference patterns. At time t=0, the waves interfere constructively. This gives a maximum in the added plot. The waves get more out of phase. This leads to destructive interference and a minimum in the added plot. From one peak maximum to the next is a cycle. So when looking at two monochromatic lights, they can be graphed as two lines in the frequency-domain (this plot shows power, P(ν), as a function of frequency). The same two lights can be plotted as the sum of their waves in the time-domain (this plot shows power, P(t), as a function of time).
Absorptions in spectra usually look like broad peaks. This means that a peak may contain many wavelengths of radiation. These wavelengths can be plotted in the time domain. Notice that there are now smaller areas of constructive interference. This is because the closely spaced wavelengths quickly become more and more out of phase.