Ultrashort Laser Pulse Phenomena, 2nd Edition

462 Diagnostic Techniques

9.2.2. Interferometric Autocorrelation

9.2.2.1. General Properties

Let us consider in more detail the particular case of the previous expressions

for the cross correlation (9.6) through (9.10) where the two fields E

1

= E

2

= E.

At τ = 0, the peak value of the function A(τ = 0) = 16



E

4

(t)dt. For large delays

compared to the pulse duration, cross products containing terms with E(t − τ)E(t)

vanish, leaving a background of A(τ =∞) = 2



E

4

(t)dt. The peak to back-

ground ratio for the interferometric autocorrelation is thus 8 to 1. The “d.c.”

term of the interferometric autocorrelation, A

0

(τ),—which is in fact an intensity

autocorrelation—has a peak to background of 3 to 1. The measurement leading

to A

0

(τ) is generally referred to as the ...