Zhen Zhang

4 Questions 4 Answers 0 Followers

Questions related from Zhen Zhang

What does negative group velocity dispersion mean?

A two-color femtosecond laser is transmitted in the air and a positive group velocity dispersion occurs. Negative group velocity dispersion is introduced when a-BBO crystal is added to the optical...

01 January 1970 382 4 View

Why does the beam shape at the focus is a Lorentz distribution rather than a Gaussian distribution?

" For most THz applications, and especially for nonlinear spectroscopy, Gaussian-shaped beam profiles are desired in order to achieve localized, well-controlled high electric field values....

01 January 1970 9,356 1 View

What does this four peaks mean in the proess of photoionization?

I saw a setup from a phd thesis saying that this was used for terahertz generation from laser induced plasma. I see four peaks in this picture, so what physical quantities do these four peaks...

01 January 1970 3,749 3 View

What is the relationship between air pressure and refractive index?

More recently, Manceau et al. demonstrated the THz polarization control via the accurate control of the surrounding gas pressure of two color filaments. The change of gas pressure will induce a...

01 January 1970 8,906 4 View