(a) Laser intensities are quoted in units of W/cm, and electric fields are quoted in units of V/cm. (i) Give the numerical value of the electric field in a laser focus of 100 W/cm intensity (a relatively low power laser focused gently), in a focus of 101 W/cm intensity (ultra high power laser focus). (ii) For a 780 nm wavelength laser focused to 101 W/cm intensity, what is the photon density (how many photons/s-cm are passing through the focus)?