History of engineering & technology InP semiconductor optical amplifier bifurcations chaos chaos synchronization chaotic communication chaotic laser diode communication system security coupled lasers coupled modes delay dual-wavelength laser dynamics and stability equivalent circuit modeling excited-state external-cavity diode laser feedback high-speed VCSELs hybrid integration hybrid photonic integration injection locking integrated lasers integrated photonic circuits intensity dynamics interference filter intra-cavity propagation delay intrinsic laser dynamics intrinsic modulation response laser chaos laser coupling