Microring resonator laser using bound states in the continuum to create a widely tunable output frequency

Lasers have had a significant impact within many fields of physics and have developed immensely in recent times. Particularly, lasers created using bound states in the continuum (BICs), which are also known as dark states, have recently become a more prominent area of study within quantum mechanics. Dark states are waves that remain localized to a specified region regardless of the flow of other waves through the system. These states are much more susceptible to manipulations of frequencies while having very little loss of energy. We created mathematical models to numerically simulate possible systems containing dark states; to obtain dark states, we added a single ring resonator to a waveguide and manipulated multiple points of connection between them. This ring interacts with the waveguide to cause interference between the connection regions. We can currently control this interference by adjusting the strength of the couplings between the waveguide and the impurity or by altering the location of the ring. These manipulations let us easily vary the dark state frequencies which allows for a continuous adjustment of the output frequency of the laser through a wide range to create a system that can be used throughout many different fields.