Feedback insensitive integrated semiconductor laser

Hoe fotonische chips ongevoelig te maken voor reflectie van lich

Model and experimental validation of a unidirectional phase modulator

\u3cp\u3eA unidirectional phase modulator consisting of tandem phase modulators is studied in detail for use as an integral part of an integrated optical isolator. The effects of non-linearity and residual amplitude modulation in the modulators, as well as the effect of the RF driving signals are captured in a phenomenological model for the first time. The model has been verified experimentally using a device realized in a generic InP based photonic integration platform and is used to study the operating range of the device. Design parameters of the modulator are derived such that modulation side bands in the forward propagating light are less than 40 dB, while isolation is maximized.\u3c/p\u3

Rate-equation theory of a feedback insensitive unidirectional semiconductor ring laser

\u3cp\u3eFor our recently designed continuous-wave and single-frequency ring laser with intra-cavity isolator, we have formulated a rate-equation theory which accounts for two sources of mutual back-scattering between the clockwise and counterclockwise modes, i.e. induced by side-wall irregularities and due to inversion-grating-induced spatial hole burning. With this theory we first confirm that for a ring laser without intra-cavity isolation, from sufficiently large pumping strength on, the inversion-grating-induced bistable operation (i.e. either clockwise or counterclockwise) will overrule the back-reflection-induced coupled-mode operation (i.e. both clockwise and counterclockwise). We then analyze the robustness of unidirectional operation in case of intra-cavity isolation against the intra-cavity back-reflection mechanism and grating-induced mode coupling and derive for this case an explicit expression for the directionality in the presence of external optical feedback, valid for sufficiently strong isolation. The predictions posed in the second reference remain unaltered in the presence of the mode coupling mechanisms here considered.\u3c/p\u3

Effects of amplitude modulation and non-linearity in phase modulators on a unidirectional phase modulator

A unidirectional phase modulator consisting of two phase modulators is studied experimentally. Analysis of the results shows the importance of non-linear and residual amplitude modulation effects in the modulators