How do I solve the following problem step by step? and what are the solution? I am really lost, and do not understand the whole exercise..
A femtosecond laser generated light pulses with a duration of only 100 fs (ie 1.00 · 10-13 s). With an ordinary lens, such a laser beam focused down to a spot with a diameter of 10 μm. A typical energy of a laser pulse from such lasers is 1 mJ. Suppose that energy is uniformly distributed over the laser spot, and the effect is constant during the pulse (a square pulse).
1.Find the intensity of the laser focus.
2. Find the amplitude, Emax, of the electric field in focus.
3. Compare this amplitude with the size of the electric field acting on an electron around the nucleus of a hydrogen atom in ground state (Hint: the distance between nucleus and electron is given by the size a0 = 5.29 · 10-11m) What does the comparison of the laser's effect on the atom
4. The laser light at a wavelength of 800 nm. Calculate how many oscillations the electromagnetic field undergoes during the pulse duration. Do you think that the frequency of such a laser will be more or less clearly defined than it is for a more traditional laser, such as a helium-neon laser? Argument and explain your answer, please.