We experimentally demonstrate large arrays of coupled whispering gallery resonators formed by droplets. Employing a fluorescent mapping technique, we measure the spatial and spectral distribution of light intensity across the modes that populate this cavity ensemble.
We experimentally demonstrate a new type of level crossing where resonances accompany each other along broad spectral bands. Beyond extending the known types of level crossing (simple, avoided, and diabolic), our accompanying levels might transform current supercontinuum-generation technology to be continuous in frequency and time [cw].
In traditional cavity optomechanical models, a coupling between the cavity field and mechanical degrees of freedom is a result of dependence of the frequency or the life-time of a cavity mode on mechanical variables. However, optical cavities with degenerate modes may exhibit a different type of optomechanical coupling, which originates from the spatial reconfiguration of the cavity field caused by mechanical motion. Such coupling can, for instance, arise in the case of whispering-gallery-modes in spherical resonators interacting with a polarizable dipole. Here we introduce a model with this previously unexplored type of optomechanical coupling, and as a first step toward understanding the properties of this model we study its classical dynamics in the absence of dissipation and an external pump. We show that the dynamical properties of such a model are characterized by a bifurcation manifested by a loss of stability of a simple equilibrium and a transition to a more complex nonlinear dynamics.
Highly symmetrical objects are important to a manifold of applications such as precise measurements and sensing. However, creating a perfect sphere proves to be experimentally extremely difficult, as gravity and the support deform the sphere from its perfect shape.
In this work, we optically levitate a micro oil droplet and activate it as whispering gallery mode optical resonator. Our contactless resonator displays a sphericity of less than one Ångström for a 10 µm radius droplet and is therefore one of the roundest objects there is. Additionally, we demonstrate an unprecedented resonance enhancement defined by “optical quality” over “mode volume” and lastly, benefitting from the high sphericity, we lift degeneracies of order higher than 200.
Using ab initio approach to the theory of electromagnetic interaction of a small particle and spherical whispering
gallery mode resonator, we derive the optical forces experienced by the particle and it's resulting motion. The
form of the forces differs from that expected by the traditional gradient/scattering approach due to the modification
of the field by the particle. The main effect of the confinement of the field in a cavity consists in making
the component of the optical force usually interpreted as gradient, manifestly non-conservative, and hence not
presentable in the gradient form. It is shown how the standard gradient/scattering formalism can be modified
for the cavity confined optical field.
Ab initio approach to description of nonlinear dynamics of individual and coupled microdisk whispering-gallerymode
resonators is developed for the nonlinearities of Kerr type. Distinction between scattering resonances and
eigenfrequencies, which is important for resonators with moderate quality factors is discussed. Properties of
various parameters important for nonlinear dynamics, such as coupling to external radiation, linear inter-disk
coupling parameter, nonlinear mode overlap coefficients are discussed from the point of view of the ab initio
formulation.
Recent observation of two-mode lasing in random lasers is discussed in the context of the problem of distinguishing between lasing with coherent and non-coherent feedback. A general semiclassical theory of lasing in cavities with a spatially non-uniform dielectric constant is developed. It is shown that the non-uniformity causes a radiative coupling between modes of the empty cavity, which results in a renormalization of the coefficients responsible for non-linear interaction between lasing modes. One of the consequences of this renormalization is the enhancement of the effects of spatial hole burning and promotion of the multi-mode lasing.
An array of quantum dots in a microcavity is considered. It is shown that a vacancy in the array may give rise to one or two quasi-local states with a long life-time depending upon the structure of the array. One state always splits off the top of the polariton gap, and the other one may appear closer to the bottom of the gap. The life-time of the state is mostly determined by the exciton non-radiative relaxation and depends only weakly upon the properties of the cavity mirrors.
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.