Deformed square microcavities composed of two partly overlapped square microcavities are proposed and investigated theoretically and experimentally. Single-mode lasing with the maximum side-mode suppression ratio (SMSR) of 39 dB and 52 dB are obtained for the deformed square microcavity lasers, connected an output waveguide to the jointed region and a vertex of the square microcavities, with a side length of 10 μm, respectively. Furthermore, higher output power is obtained for the deformed square microcavity laser with a vertex output waveguide than that with an output waveguide to the jointed region.
We report nonlinear dynamics in directly connected twin circular-sided square microcavity semiconductor lasers with mutual optical injection. Rich nonlinear dynamics including injection locking, four-wave fixing, and multi-period oscillation states are observed experimentally by adjusting the mode frequency offset between two circular-side square microcavities. Internal optical injection or mode coupling can be realized directly in the connected twin circular-sided square microcavity lasers, which effectively relaxes device processing techniques of the integrated microcavities for photonic integration.
A numerical scheme for calculating phase noise is proposed for hybrid square-rectangular semiconductor lasers. By establishing a two-section single-mode rate equation model driven by Langevin noise sources and considering the nonlinear gain effect, we numerically studied the phase noise characteristics and linewidth of the hybrid-cavity laser. The time-varying spectra of carrier density, photon density and phase are simulated and the frequency spectra of phase noise are presented with the help of the fast Fourier transform. With the increase of the bias current, the frequency noise has an obvious downward trend and a narrower linewidth is obtained. The linewidth of the hybrid square-rectangular laser is calculated according to the phase noise at low frequency. The simulated linewidth of the hybrid-cavity semiconductor laser is 0.36 MHz at the linewidth enhancement factor of 3 when the square microcavity bias current is 20 mA and the FP cavity bias current is 100 mA.
Whispering-gallery mode (WGM) microcavities with the merits of small mode volumes and high quality (Q) factors have attracted great research interests as potential low-power-consumption light sources for photonic integration. We propose and demonstrate deformed square microcavity lasers with the flat sidewalls replaced by circular arcs as converge mirrors to control the WGMs inside the laser cavity. The ray dynamic analysis results indicate that the circular-sides can confine the light rays with stable islands, although full chaotic dynamics are observed under certain deformation. With the numerical simulation of the circular-side square microcavities, ultrahigh-Q modes are obtained owing to the elimination of the scattering losses from the vertices, and a reduction of mode Q factors due to the chaotic ray dynamics is also observed. Different transverse modes have distinct light trajectories, which results in a difference of the effective roundtrip length and a controllable transverse mode interval. Low threshold lasing is achieved experimentally due to the high Q factors of the WGMs. The lasing spectra can be engineered by designing the cavity geometry for the waveguidecoupled circular-side square microcavity lasers. The robust structure and ultrahigh-Q of the waveguide-coupled microlasers provide a potential solution for the compact light sources in photonic integrated circuits.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.