Laser linewidth measurement based on long and short delay fiber combination

We present a numerical calculation with iterative algorithm method for accurately measuring laser linewidth. In this new method, the self-heterodyne spectrum of long delay fiber is calculated as the initial value, and the short delay self-heterodyne spectrum is demodulated with iterative algorithm to realize the accurate measurement of laser linewidth. The method can eliminate the influence of 1/f noise on the measurement spectrum broadening, so it provides a powerful way tbr accurate measurement of narrow linewidth. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

The method utilizes an iterative algorithm to accurately measure laser linewidth, eliminating the influence of 1/f noise on spectrum broadening, providing an effective approach for accurate measurement of narrow linewidth.