On the calculation of 1/f frequency noise effects on self-heterodyne linewidth measurements

Numerical calculation errors are found in a widely cited paper published in Journal of Lightwave Technology, to our humble opinion. The errors result in the calculated 1/f noise linewidth much larger in heterodyne measurement and matching the measured linewidth. Our re-calculation results show that the 1/f noise linewidth in heterodyne measurement is about one order smaller than previously calculated and indicates a discrepancy between theory and measurements.