Nonlinear dynamics induced by external optical injection in ...

Nonlinear dynamics in semiconductor lasers 771
Figure 4. Measured optical spectra of the conventional, edge-emitting semiconductor laser with
J ˜ = 2 3 under optical injection at the free-running optical frequency: (a) free-running operation
with an expanded scale showing the relaxation resonance sidebands; (b) unstable injection
locking, limit cycle, at ξ 2 = 1 × 10 −4 with an expanded scale spectrum; (c) period doubling
at ξ 2 = 3 × 10 −4 with features shown clearly in the expanded scale; (d) chaotic dynamics at
ξ 2 = 1.3×10 −3 ;(e) limit cycle at ξ 2 = 3.6×10 −3 ;(f) period doubling at ξ 2 = 7.2×10 −3 ;(g)
transition back to the limit cycle at ξ 2 = 1.7 × 10 −2 and (h) stable operation at ξ 2 = 8.5 × 10 −2
along with an expanded scale spectrum and the expanded scale sideband spectrum of the master
laser.