A 200 MW laser pulse is focused with a lens to a diameter of 2.0 m. a.

A 200 MW laser pulse is focused with a lens to a diameter of 2.0 μm.
a. What is the laser beam’s electric field amplitude at the focal point?
b. What is the ratio of the laser beam’s electric field to the electric field that keeps the electron bound to the proton of a hydrogen atom? The radius of the electron orbit is 0.053 nm.