Study on enlarging chaos frequency in two coupled lasers using both optoelectronic cross-feedback and self-feedback

Abstract

Abstract This paper presents an optoelectronic delayed time cross-feedback and self-feedback method to enlarge chaotic frequencies of two semiconductor lasers as two chaotic signal oscillators and to enhance the oscillation behaviours of the lasers. The technical solution of enlarging-frequency of two lasers is that the light from one laser is converted into a photocurrent by the photoelectric converter, and then the delayed time photocurrent is divided into two currents. One is cross fed to another laser while the other photocurrent is fed to self-laser, which can result in enhancing chaos oscillation to realize enlargement of chaotic frequency of two semiconductor lasers. We adjust the feedback levels or the delayed time to realize enlargement of chaotic frequency of two semiconductor lasers. When the feedback level increased, enlargement of the chaotic frequency of the two semiconductor lasers is obviously enhanced. When a feedback is performed, enlargement of chaotic frequency of one laser is obviously enhanced. When the two feedbacks are performed, enlargements of chaotic frequencies of two lasers are obviously enhanced. These results illustrate that enlargement of chaotic frequency of two laser can be effectively obtained via the optoelectronic delayed time cross-feedback and self-feedback method. The research result of this paper is a reference value for enlargement of chaotic frequency, chaos communization, and laser technology etc.