RT Journal Article T1 Fresnel diffraction effects in Fourier-transform arrayed waveguide grating spectrometer A1 Rodrigo Martín-Romo, José Augusto A1 Cheben, Pavel A1 Alieva Krasheninnikova, Tatiana A1 Calvo Padilla, María Luisa A1 Scott, Alan A1 Solheim, Brian A1 Xu, Dan-Xia A1 Delâge, André AB We present an analysis of Fourier-transform arrayed waveguide gratings in the Fresnel diffraction regime. We report a distinct spatial modulation of the interference pattern referred to as the Moire-Talbot effect. The effect and its influence in a FT AWG device is explained by deriving an original analytical expression for the modulated field, and is also confirmed by numerical simulations using the angular spectrum method to solve the Fresnel diffraction integral. We illustrate the retrieval of spectral information in a waveguide Fourier-transform spectrometer in the presence of the Moire-Talbot effect. The simulated device comprises two interleaved waveguide arrays each with 180 waveguides and the interference order of 40. It is designed with a Rayleigh spectral resolution of 0.1 nm and 8 nm bandwidth at wavelength λ~1.5 µm. We also demonstrate by numerical simulations that the spectrometer crosstalk is reduced from -20 dB to -40 dB by Gaussian apodization. PB The Optical Society Of America SN 1094-4087 YR 2007 FD 2007-12-10 LK https://hdl.handle.net/20.500.14352/51040 UL https://hdl.handle.net/20.500.14352/51040 LA eng NO © 2007 Optical Society of America.The financial support of the Spanish Ministry of Education and Science under project TEC2005-02180 and ”Slab Waveguide Spatial Heterodyne Spetrometer project”, Contract 9F028-064201/007/MTB, Space Technology Development Program, Canada Space Agency are acknowledged. NO Ministerio de Educación y Ciencia, España NO Canada Space Agency DS Docta Complutense RD 10 abr 2025