Publications
Selected work in non-Hermitian optics and scattering theory.
- i. Coherent perfect absorption at an exceptional point
Abstract. Recently, exceptional points, a degeneracy of open wave systems, have been observed in photonics, acoustics, and electronics. They have mainly been realized as a degeneracy of resonances; however, a degeneracy associated with the absorption of waves can exhibit distinct and interesting physical features…
- ii. Electromagnetic Induced Polarization
Abstract. Polarization of optical fields is a crucial degree of freedom in the all-optical analogue of electromagnetically induced transparency (EIT). However, the physical origins of EIT and polarization-induced phenomena have not been well distinguished, which can lead to confusion in associated applications such as slow light and optical/quantum storage. Here we study the polarization effects in various optical EIT systems…
- iii. Reflectionless excitation of arbitrary photonic structures: a general theory
Abstract. We outline and interpret a recently developed theory of impedance matching or reflectionless excitation of arbitrary finite photonic structures in any dimension…
- iv. Theory of reflectionless scattering modes
Abstract. We develop the theory of a special type of scattering state in which a set of asymptotic channels is chosen as inputs, and the complementary set is chosen as outputs, and there is zero reflection back into the input channels at specific frequencies…
- v. Electromagnetic Eigenvalue Problems and Nonhermitian Effects in Linear and Saturable Scattering
Abstract. In this thesis we address a series of new problems in non-hermitian optical scattering — linear and nonlinear — with increasing degrees of complexity…
- vi. Quantum Noise Theory of Exceptional Point Amplifying Sensors
Abstract. Open quantum systems can have exceptional points (EPs), degeneracies where both eigenvalues and eigenvectors coalesce. Recently, it has been proposed and demonstrated that EPs can enhance the performance of sensors in terms of amplification of a detected signal. However, typically amplification of signals also increases the system noise, and it has not yet been shown that an EP sensor can have improved signal-to-noise performance. We develop a quantum noise theory to calculate the signal-to-noise performance of an EP sensor…
- vii. Perfectly Absorbing Exceptional Points and Chiral Absorbers
Abstract. We identify a new kind of physically realizable exceptional point (EP) corresponding to degenerate coherent perfect absorption, in which two purely incoming solutions of the wave operator for electromagnetic or acoustic waves coalesce to a single state…