An alternative approach to determine the spot-size of a multi-mode laser beam and its application to diode laser beams

An alternative approach is suggested to determine the spot-size of a multi- mode laser beam. It has been shown by simulations that the suggested approa ch can give the beam quality factor and characteristic radius with less tha n 5% error. Unlike the power content method, the proposed method is applica ble to the beams even with diameter one tenth of the CCD size. The new appr oach has been applied to a multi-mode diode laser output and it is shown th at the ABCD matrix analysis can be used for beam propagation, with the meas ured parameters of the laser.