Atmospheric Transmission Windows for High Energy Short Pulse Lasers

The US Navy is exploring the feasibility of using a high energy laser weapon as a ship-borne self-defense system against sea-skimming cruise missile attacks. Since the attenuation of laser energy by the atmosphere is the highest at low altitudes and varies with frequency, the selection of appropriate wavelengths becomes critical for a laser weapon to be effective. A high energy free electron laser (FEL) is suitable for employment in the envisaged role because it can be designed to operate at any desired frequency and, to a degree, is tunable in operation. This study aims to determine the optimal atmospheric windows for high energy, pico second, short pulse lasers. Computer simulations were carried out by convolving a pulse spectrum with the transmission spectrum and the absorption coefficient from the MODTRAN and FASCODE atmospheric codes. Transmission spectrum and absorption coefficient plots were compared to find the range of suitable wavelengths that give good transmittance and low absorption coefficient values.Naval Postgraduate School Monterey CA is the author of 'Atmospheric Transmission Windows for High Energy Short Pulse Lasers', published 2003 under ISBN 9781423513766 and ISBN 1423513762.