Susumu SHINOHARA¹, Takehiro FUKUSHIMA², Satoshi SUNADA³, Takahisa HARAYAMA^1,4, Kenichi ARAI¹, and Kazuyuki YOSHIMURA¹

¹NTT Communication Science Laboratories, NTT Corporation, Seika, Kyoto 619-0237, Japan
²Department of Information and Communication Engineering, Okayama Prefectural University, Soja, Okayama 719-1197, Japan
³Institute of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan
⁴Department of Mechanical Engineering, Toyo University, Kawagoe, Saitama 350-8585, Japan

(Received October 28, 2013; Accepted December 31, 2013)

Time-domain properties of the output from quasistadium-shaped microcavity semiconductor lasers are studied. Ring modes generating a bidirectional output are selectively excited by partial pumping. We observe a high anticorrelation between the two beams output from the ring modes. This can be considered as the generalization of alternate oscillations reported previously. We find that the outputs exhibit a robust slow modulation of 4–10 MHz, and explain it by the quasi-degeneracy of the resonator modes.

Key words: two-dimensional laser diodes, bidirectional output, nonlinear dynamics, resonator modes