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Recent years have witnessed an inflow of ideas from quantum field theory and condensed matter physics into the field of optics. In this talk, we describe how notions from topological physics and supersymmetry can be used in designing novel laser arrays with properties that are of interest in some applications. Likewise, such lasing arrangements can be used to emulate a variety of topological and supersymmetric phenomena, beyond what is possible in their respective original platforms.

A non-Hermitian He-Ne ring laser gyroscope (RLG) that operates at an exceptional point is proposed and experimentally realized. Compared to a standard RLG, the device exhibits more than an order of magnitude enhancement in sensitivity.

Gyroscopes are essential to many diverse applications associated with navigation, positioning and inertial sensing

Supersymmetric transformations aim to relate boson and fermions, two different species of particles, and their interactions. In quantum mechanics, the mathematical framework of SUSY can be used to design isospectral potentials. By virtue of the isomorphism between Schrodinger and wave equations, one can use such transformations for designing novel optical systems. In this talk, we review the recent developments in the general area of supersymmetric optics and photonics. We will also discuss the possibility of generating high brightness coherent light in supersymmetric laser arrays.

Stability through symmetry A common route to get more light out of a laser system is to couple multiple lasers to form an array. However, instabilities owing to cross-talk and interference between different modes of individual cavities is generally detrimental to performance and could ultimately be damaging to the laser cavities. Hokmabadi et al. applied notions derived from supersymmetry, a theory developed in high-energy physics to describe the make-up and properties of particles, to design a stable array of semiconductor lasers (see the Perspective by Kottos). Based on symmetry arguments, the method is scalable and could provide a practical platform to design and develop complex photonic systems. Science , this issue p. 623 ; see also p. 586

The synergetic use of gain and loss in parity-time symmetric coupled resonators has been shown to lead to single-mode lasing operation. However, at the corresponding resonance frequency, an ideal ring resonator tends to support two degenerate eigenmodes, traveling along the cavity in opposite directions. Here, we show a unidirectional single-moded parity-time symmetric laser by incorporating active S-bend structures with opposite chirality in the respective ring resonators. Such chiral elements break the rotation symmetry of the ring cavities by providing an asymmetric coupling between the clockwise (CW) and the counterclockwise (CCW) traveling modes, hence creating a new type of exceptional point. This property, consequently, leads to the suppression of one of the counter-propagating modes. In this paper, we first measure the extinction ratio between the CW and CCW modes in a single ring resonator in the presence of an S-bend waveguide. We then experimentally investigate the unidirectional emission in PT-symmetric systems below and above the exceptional point. Finally, unidirectional emission will be shown in systems of two S-bend ring resonators coupled through a link structure.

A multimode, chaotic, and broadband emission is an undesired characteristic of laser arrays which is an adverse effect of supermodes in coupled waveguides. Employing optical supersymmetry, we experimentally demonstrate single mode lasing in arrays of supersymmetric lasers where a superpatner array eliminates undesired lasing modes.

A new scheme for ultrasensitive micro-ring laser gyroscopes based on the physics of exceptional points is proposed. In such systems, the sensitivity to low rotation rates can be enhanced by several orders of magnitude.

Multimode emission adversely affects phased-locked laser arrays resulting in chaotic behaviors. Utilizing optical supersymmetry, we experimentally demonstrate a single mode laser array where a superpartner array eliminates undesired higher order transverse modes.

We present our progress towards the realization of room temperature current-injected coaxial nanolasers. Lasing action is demonstrated in a metallic coaxial resonator up to a temperature of 140 K.

At resonance, mircoring resonators tend to support two counter-propagating degenerate modes. By incorporating S-bend chiral elements in each resonator, unidirectional single mode lasing below and above PT-symmetry breaking point is experimentally demonstrated.