Single-peak narrow-bandwidth mid-infrared thermal emitters based on quantum wells and photonic crystals

摘要

We experimentally demonstrate single-peak narrow-bandwidth thermal emission with a quality factor (Q factor) of more than 100 at a wavelength of 9.1?μm. The emission is significantly suppressed at all other wavelengths. Our emitter is based on an intersubband transition in a multiple quantum well structure combined with a single high-Q resonant mode in a two-dimensional photonic crystal slab, which allows strong light-matter interaction only at a specific wavelength. Strong thermal emission is exhibited only in a limited angular range (～20°) from the normal direction. Our results have potential applications in bio- and environmental sensors.