the group delay is a distance divided by the group velocity. For experiments tha
ID: 1688049 • Letter: T
Question
the group delay is a distance divided by the group velocity. For experiments that generate x-rays from infrared light, it's very important that the difference between the phase delay and group delay be carefully controlled, so that the peak in the pulse envelope coincides with a peak in the underlying sine wave (that generates the highest possible electric field at that point).Derive an expression for the difference between the phase delay and the group delay in terms of the vaccum wavelength lambda 0, the distance L, the refractive index n, and its derivative with respect to the vacuum wavelength lambda0
Explanation / Answer
The Phase velocity v = c/n Here c is light velocity,n is refractive index The Group velocity V_g = c/n_g n_g is refractive index for the group of waves in the medium The phase delay t_p = L/v = Ln/c----------(1) Here L is distance travelled by the particle The group delay t_g = L/v_g = Lc/n_g Here n_g = n - ?_0*(dn/d?_0) The difference between group delay and phase delay t_g - t_p = L/c(n - n_g) t_g - t_p = L/c(n- ( n - ?_0*( dn/d?_0)) t_g - t_p = L/c(?_0*( dn/d?_0)Related Questions
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