METHOD FOR MEASURING SPECTRUM LINE WIDTH OF RING LASER

摘要

PROBLEM TO BE SOLVED: To provide a method for measuring the line width of the spectrum of a ring laser easily without any large-scale devices.;SOLUTION: A ring laser to be measured consists of a semiconductor optical amplifier 1, and a single-mode optical fiber loop 2 with a total length of 3 m. Also, the semiconductor optical amplifier is driven by a power supply 3, and a voltage across the terminals of the semiconductor optical amplifier is measured by an oscilloscope 4. When the ring laser is rotated within a surface including an annular optical waveguide, a pulsive beat signal is generated. The time interval of the peaks of the beat signal on the pulse is read from each screen, reciprocally converted to a frequency and is averaged, thus obtaining a beat frequency. Then, the pulse width of each pulse is converted to a frequency similarly, and the difference to the beat frequency is calculated, thus calculating the spectrum line width.;COPYRIGHT: (C)2001,JPO