Locally deformed-ring hybrid microlasers exhibiting stable unidirectional emission from a Si waveguide.

We propose and demonstrate a locally deformed-ring (LDR) hybrid microlaser to realize stable unidirectional emission from a silicon waveguide. The coupled modes eliminate the competition between clockwise (CW) and counter-clockwise (CCW) modes, and the highly unidirectional characteristics are achieved with an enhanced mode quality factor based on a locally deformed notch in the LDR resonator. Using a divinylsiloxane-benzocyclobutene bonding technique, a LDR hybrid microlaser is fabricated vertically coupled to a silicon waveguide with a radius of 20 μm, a ring width of 4 μm and a notch width of 500 nm.

Hybrid spiral-ring microlaser vertically coupled to silicon waveguide for stable and unidirectional output.

A hybrid spiral-ring laser vertically coupled to a silicon waveguide is demonstrated to achieve stable and unidirectional output theoretically and experimentally. The mode competition between clockwise (CW) and counter-clockwise (CCW) modes is eliminated due to the mode coupling in a spiral resonator. The simulation results indicate that the CCW and CW direction traveling waves are dominant components, respectively, for the spiral resonator without and with an output waveguide.

Mode selection in square resonator microlasers for widely tunable single mode lasing.

Mode selection in square resonator semiconductor microlasers is demonstrated by adjusting the width of the output waveguide coupled to the midpoint of one side. The simulation and experimental results reveal that widely tunable single mode lasing can be realized in square resonator microlasers. Through adjusting the width of the output waveguide, the mode interval of the high-Q modes can reach four times of the longitudinal mode interval.