Related papers: Extra Loss-free Non-Hermitian Engineered Single Mo…
We report parity-time (PT) symmetry breaking in electrically injected, coherently coupled, vertical cavity surface emitting laser arrays. We predict beam steering, mode evolution and mode hopping as a consequence of the non-Hermiticity of…
We predict and observe the appearance of an excess noise factor due to the non-Hermiticity of the modes of two actively harmonically mode-locked lasers. The non uniform distribution of gain and losses in the ring cavities of these lasers…
Two-dimensional (2D) laser arrays are shown to be achievable at a large scale by exploiting the interplay of higher-order topological insulator (HOTI) physics and the so-called non-Hermitian skin effect (NHSE). The higher-order topology…
We propose a time-dependent partial differential equation model to investigate the dynamical behavior of the parity-time (PT) symmetric laser during the nonlinear stage of its operation. This model incorporates physical effects such as the…
The continuous advancements in ultrafast lasers, characterized by high pulse energy, great average power, and ultrashort pulse duration, have opened up new frontiers and applications in various fields such as high-energy-density science. In…
Non-Hermitian optical systems with parity-time (PT) symmetry have recently revealed many intriguing prospects that outperform conservative structures. The prevous works are mostly rooted in complex arrangements with controlled gain-loss…
We present a novel laser mode-locking scheme and discuss its unusual properties and feasibility using a theoretical model. A large set of single-frequency continuous-wave lasers oscillate by amplification in spatially separated gain media.…
Non-Hermitian systems with parity-time symmetry have been found to exhibit real spectra of eigenvalues, indicating a balance between the loss and gain. However, such a balance is not only dependent on the magnitude of loss and gain, but…
We propose to utilize symmetry-protected zero modes of a photonic lattice to realize a single-mode, fixed-frequency, and spatially tunable laser. These properties are the consequence of the underlying non-Hermitian particle-hole symmetry,…
Single mode lasing is experimentally demonstrated in a transversely multi-moded InP-based semiconductor microring arrangement. In this system, mode discrimination is attained by judiciously utilizing the exceptional points in a parity-time…
Photonic integrated circuits are paving the way for novel on-chip functionalities with diverse applications in communication, computing, and beyond. The integration of on-chip light sources, especially single-mode lasers, is crucial for…
We analyze the guided modes in coupled waveguides made of negative-index materials without gain or loss. We show that it supports non-Hermitian phenomenon on the existence of guided mode versus geometric parameters of the structure. The…
In a non-Hermitian optical system with loss and gain, an exceptional point (EP) will arise under specific parameters where the eigenvalues and eigenstates exhibit simultaneous coalescence. Here we report a dynamical switching of lasing…
Shaping the light emission characteristics of laser systems is of great importance in various areas of science and technology. In a typical lasing arrangement, the spatial profile of the mode tends to remain self-similar throughout the…
A self-consistent integral equation is formulated and solved iteratively which determines the steady-state lasing modes of open multi-mode lasers. These modes are naturally decomposed in terms of frequency dependent biorthogonal modes of a…
We explore a new class of Distributed Feedback (DFB) structures that employ the recently-developed concept of Parity-Time (PT) symmetry in optics. We demonstrate that, based on PT-symmetric pure reflective volume gratings, vertical cavity…
Optically-coupled semiconductor laser arrays are described by coupled rate equations. The coupled mode equations and carrier densities are included in the analysis, which inherently incorporate the carrier-induced nonlinearities including…
We measure the lasing dynamics of single and coupled photonic crystal nanocavity array lasers fabricated in the indium gallium arsenide phosphide material system. Under short optical excitation, single cavity lasers produce pulses as fast…
Quantum sensing near exceptional points (EPs) in non-Hermitian systems has shown promising sensitivity enhancements. However, practical applications are often hindered by structural complexity and strict parameter constraints. In this work,…
One of the most fundamental questions in laser physics is the following: Which mode of an optical cavity will reach the lasing threshold first when gain is applied? Intuitively, the answer appears straightforward: When a particular mode is…