0000000000086344
AUTHOR
Gwenn Ulliac
Near IR stationary wave Fourier transform lambda meter in lithium niobate: multiplexing and improving optical sampling using spatially shifted nanogroove antenna
Several integrated optics solutions currently exist to develop monolithic, robust, and lightweight high-resolution spectrometers for spatial applications. An interesting option is generating a stationary wave inside a single-mode waveguide, and sampling the interference fringes using dielectric discontinuities on the surface of the waveguide. This allows the recording of the signal on a detector on top of the waveguide, and using dedicated Fourier transform methods to recover the spectrum of the source. All the difficulty is then linked to the length of the interferogram that is sampled. This determines the spectral resolution and the spacing between sampling centers, which are ultimately l…
Improving the vertical radiation pattern issued from multiple nano-groove scattering centers acting as an antenna for future integrated optics Fourier transform spectrometers in the near IR
The stationary wave integrated Fourier transform spectrometer (SWIFTS) is based on the sampling of a stationary wave using nano-scattering centers on the surface of a channel waveguide. Single nano-scale scattering centers above the waveguide surface will radiate the sampled signal with wide angular distribution, which is not compatible with the buried detection area of infrared (IR) detectors, resulting in crosstalk between pixels. An implementation of multiple diffraction nano-grooves (antenna) for each sampling center is proposed as an alternative solution to improve directivity towards the detector pixel by narrowing the scattering angle of the extracted light. Its efficiency is demonst…