Efficient Vertical-Cavity Mid-IR Thermal Radiation to Silicon-Slab Waveguide Coupling Using a Shallow Blazed Grating

Abstract

Abstract:In this work we investigate the coupling of radiation originating from a vertical-cavity enhanced thermal emitter (VERTE) into an optical waveguide, which can, for instance, act as a sensing element. We present full wave modelling results demonstrating highly efficient emitter-to-waveguide diffraction coupling at multiple angles using the previously designed VERTE together with a shallow blazed grating. It is shown that the coherent and dispersive thermal emission of the VERTE concept is well suited to achieve highly efficient and integrated mode coupling in the mid IR region.

Design and Numerical Evaluation of a Highly Selective CMOS-Compatible Mid-IR Thermal Emitter/Detector Structure Using Optical Tamm-States

“…We utilize Kirchhoff's law and reciprocity by simulating the reciprocal situation of an incident guided mode (propagating in positive x-direction) and evaluate the power absorbed by the silver via Poynting's theorem. This approach allows efficient simulation of plasmonic emitter structures (see e.g., [1,6,7]).…”

Towards Integrated Mid-Infrared Gas Sensors

“…Nevertheless, renewed scientific interest in the miniaturization of low-cost optical gas sensors [43,54,63], is being fueled by advances in silicon micromachining [36,87]. Recently, membrane microhotplates based on MEMS technology [88,89,90] (Figure 4), came up as compact, integrated thermal light sources [42,43,91]. MEMS heaters are proven to be energy efficient [90], allow for rapid modulation owing to their low thermal mass [19,90], and are compatible with standard CMOS foundry processes [19,90].…”

“…Nondispersive gas sensors relax the requirements on the MIR light sources and detectors [3,19,73], hence exploiting standard CMOS processes is an attractive route towards the fabrication of low-cost integrated thermal emitters and detectors [36]. For this reason, membrane MEMS devices emerged as MIR light sources [36,89,90,91] and detectors [92,100,101], with various thermal engineering techniques, e.g., based on: photonic crystals [55], multi-quantum well structures [102], resonant-cavities [103], carbon nanoparticle adlayers [94,95], and plasmonic metamaterials [42,43]. Among these, the overall broadband emission enhancement (almost unity) offered by carbon-based nanomaterial adlayers [94,95], are of particular interest for spectroscopy.…”