1. K. Uchiyama, M. Saruwatari and S. Kawanishi: Proc. Euro. Conf. on Opt. Comm. (ECOC’97), Edinburgh, 1997, WE2A-1.
2. L.H. Spiekman, U. Koren, B.I. Miller, M.D. Chien and J.M. Wiesenfeld: Proc. of Topical Meeting of Optical Amplifiers and Their Applications (OAA’98), Colorado, 1998, WB5.
3. M.A. Saummerfield, J.P.R. Lacy, A.J. Lowery and R.S. Tucker: IEE Electron. Lett. 30 (1994) 255.
4. K. Nonaka, Y. Noguchi and T. Kurokawa: Jpn. J. Appl. Phys. 36 (1997) 4326.
5. H. Kawaguchi: Bistabilities and Nonlinearities in Laser Diodes (Artech House, Boston, 1994) p. 29.