TY - JOUR
T1 - Quantification of orbital instability of chaotic laser diode
AU - Ebisawa, Satoshi
AU - Maeda, Joji
AU - Komatsu, Shinichi
PY - 2018/11/1
Y1 - 2018/11/1
N2 - We studied two methods that quantify the orbital instability of a laser diode (LD) in two typical chaotic systems. In one method, a coefficient named the orbital expansion exponent (OEE) is calculated from only the time series of the laser intensity. In the other method, the Lyapunov exponent is calculated from the rate equations. Then we compared the OEE and the Lyapunov exponent to discuss the appropriateness of the OEE. In an optical feedback LD system, the OEE cannot represent the dynamics of the chaotic LD satisfactorily for the large feedback ratio. However, when the LD has a larger drive current and the inherent parameters of the LD are dominant in the dynamics, the OEE represents the dynamics of the chaotic LD as well as the Lyapunov exponent. On the other hand, in an optical injection LD system, the correlation coefficient between the OEE and the Lyapunov exponent is large even if the injection ratio is large. To find the reason for this, we replaced the optical feedback system with a multistage optical injection system, and showed that the feedback terms prevent the OEE from accurately representing the orbital instability of a chaotic laser.
AB - We studied two methods that quantify the orbital instability of a laser diode (LD) in two typical chaotic systems. In one method, a coefficient named the orbital expansion exponent (OEE) is calculated from only the time series of the laser intensity. In the other method, the Lyapunov exponent is calculated from the rate equations. Then we compared the OEE and the Lyapunov exponent to discuss the appropriateness of the OEE. In an optical feedback LD system, the OEE cannot represent the dynamics of the chaotic LD satisfactorily for the large feedback ratio. However, when the LD has a larger drive current and the inherent parameters of the LD are dominant in the dynamics, the OEE represents the dynamics of the chaotic LD as well as the Lyapunov exponent. On the other hand, in an optical injection LD system, the correlation coefficient between the OEE and the Lyapunov exponent is large even if the injection ratio is large. To find the reason for this, we replaced the optical feedback system with a multistage optical injection system, and showed that the feedback terms prevent the OEE from accurately representing the orbital instability of a chaotic laser.
KW - Chaotic laser diode
KW - Laser chaos
KW - Optical feedback
KW - Optical injection
KW - Semiconductor laser
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U2 - 10.1016/j.ijleo.2018.07.134
DO - 10.1016/j.ijleo.2018.07.134
M3 - Article
AN - SCOPUS:85050659547
VL - 172
SP - 908
EP - 916
JO - Optik
JF - Optik
SN - 0030-4026
ER -