ABSTRACT
The selective spatial mode excitation of a bi-dimensional grating-coupled micro-cavity called a cavity resonator integrated grating filter (CRIGF) is reported using an incident beam shaped to reproduce the theoretical emission profiles of the device in one and subsequently two dimensions. In both cases, the selective excitation of modes up to order 10 (per direction) is confirmed by responses exhibiting one (respectively two) spectrally narrowband resonance(s) with a good extinction of the other modes, the latter being shown to depend on the parity and order(s) of the involved modes. These results pave the way toward the demonstration of multi-wavelength spatially selective reflectors or fiber-to-waveguide couplers. Also, subject to an appropriate choice of the materials constituting the CRIGF, this work can be extended to obtain mode-selectable laser emission or nonlinear frequency conversion.
ABSTRACT
The image formation in coded aperture spectral imagers is key information for processing the acquired compress data, and the optical system design and calibration of these instruments require great care. We propose an analytical model for CASSI systems that builds upon ray-tracing equations of each optical component. The model takes into account optical distortions, sampling effects, and optical misalignments, and allows accurate modeling and fast calibration. Numerical comparisons with a simpler model usually exploited in the literature are provided, and an experimental validation is presented.
