Single-defect Bragg stacks for high-power narrow-band thermal emission

Abstract

The radiative properties of single-defect Bragg stacks are investigated in the midinfrared region with the transfer-matrix theory. For a sufficiently small number of layers we find a regime where the structure emits radiation within a narrow range of wavelengths (δλ∕λ⩽0.01) and with an emissivity close to 1 in all directions. A description of the electric-field distribution inside the structure allows us to interpret this behavior in terms of coupling between the localized defect states and surface waves. This result should find broad applications in infrared spectroscopy, chemical sensing, and thermophotovoltaic conversion.