Abstract
Chaotic oscillation in a single-mode He-Ne laser (6328 Å), which belongs to a class A laser, is investigated through experiments I which were reported in our previous paper [F. Kuwashima, I. Kitazima and H. Iwasawa: Jpn. J. Appl. Phys. 37 (1998) L325.], and the improved experiments II. The results of experiments II, which were conducted using a neutral density (ND) filter instead of the tilted mirror used in experiments I, demonstrate the effect of the tilted mirror and a pumping parameter on the chaotic behavior of this laser. We also confirm and discuss the threshold value for chaos vs control parameters from the estimated Lyapunov exponents. The route to chaos in this laser is also discussed. Lastly, the laser equation of the class A laser with delayed feedback is introduced and numerical results which reveal chaotic oscillations are reported.