Solve first six question only

A Ti:Sapphire pulsed laser emits laser radiation at 1, = 800 nm, and the repetition rate of the pulse chain is 80 MHz (i.e., 80 million pulses are produced per second). The duration of each pulse is 100 femtosecond. The average power of the laser output is measured to be 2.5 Watt. (1) What is the optical frequency of the laser output? (2) What is the photon energy of the light? Express your answer in both Joule and ev. (3) What is the wavenumber (or wave-vector) of the light wave? (4) What is the energy of each pulse? (5) How many photons are contained in one pulse? (6) What is the peak power of the laser pulse? (7) If the laser beam is focused to a diameter of 100 um, what is the peak intensity (in the unit of W/cm?) of the laser (note: intensity = power/area)? (8) What is the optical frequency of the light inside a piece of glass (n=1.5)? (9) What is the wavelength of the light inside a piece of glass? (10) What is the photon energy of light inside a piece of glass