Work

Monochromatic spatial response measurement for focal plane array with an heterodynally referenced optical grating

Year: 2026

Type: article

Abstract: Accurate generation of well-defined spatial frequencies remains a key challenge in many imaging applications. A particularly demanding case is the spatial response measurement of focal plane arrays (FPAs). For small-pitch FPAs, where pixel size approaches the wavelength, classical optical systems act as stronger filters than the detectors themselves, making reliable modulation transfer function evaluation difficult. Uncertainty in the optical transfer function of the projection system, and thus in the projected spatial frequencies, further undermines measurement accuracy. In hyperspectral imaging, this challenge is compounded by the need for monochromatic response measurements at multiple wavelengths. To address these limitations, we introduce a novel type of grating that generates two-dimensional sparse spatial frequencies whose amplitudes are quantitatively encoded along the optical axis through a longitudinal heterodyne signature. As this signature depends on both spectral and spatial parameters, the proposed grating provides a robust approach for precise monochromatic transfer function characterization of FPAs.

Source: Optics Communications

DOI: 10.1016/j.optcom.2026.133370

Authors: Pierre Arrondeau, Edouard Huard de Verneuil, Jérôme Primot, Clémentine Durnez, Sophie Derelle

Institutions: Université Paris-Saclay, Centre National d'Études Spatiales, Office National d'Études et de Recherches Aérospatiales, Département Optique et Techniques Associées

Language: English

Topic: Advanced Semiconductor Detectors and Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,600

Funder: Centre National d’Etudes Spatiales