Electronics Letters, Volume 23, Issue 9, 23 April 1987, p. 450 – 451
The classical Schawlow–Townes formula for the linewidth of a laser should be multiplied by a factor K’ = (1+αA2)K/2. In this formula, αA, is the ratio of changes in the real and imaginary parts of the compl resonant frequency resulting from a change in carrier density, and K is Petermann’s factor. It is shown here that this factor is identical to a result reported in 1971 by other authors in connection with impact oscillators.
LIEN VERS L’ARTICLE : ROLE OF PETERMANN’S K-FACTOR IN SEMICONDUCTOR LASER OSCILLATORS A FURTHER NOTE