Effects of scan angles in the far-field scanning method on the measurement of the mode field diameter

The far-field (FF) scanning technique and the Petermann II definition were used to measure the mode field diameter (MFD) of a step-index single-mode fiber (SMF). Studies were conducted to see how the choice of the maximum scan angle and the angle resolution value could affect the value of the measured MFD. A maximum scan angle of 12/spl deg/ and resolution angle of 0.5/spl deg/ is essential in order to obtain an accurate value for the MFD.