Spectral Diffractive Lenses for Measuring a Modified Red Edge Simple Ratio Index and a Water Band Index
- Resource Type
- Authors
- V. A. Blank; Leonid L. Doskolovich; Nikolay L. Kazanskiy; Roman V. Skidanov
- Source
- Sensors, Vol 21, Iss 7694, p 7694 (2021)
Sensors
Volume 21
Issue 22
Sensors (Basel, Switzerland)
- Subject
- Diffraction
Materials science
Fabrication
Physics::Optics
Red edge
Astrophysics::Cosmology and Extragalactic Astrophysics
TP1-1185
Photoresist
Biochemistry
Article
Analytical Chemistry
law.invention
Optics
law
hyperspectrometer
Electrical and Electronic Engineering
Image sensor
Instrumentation
Lenses
diffractive lenses
business.industry
Chemical technology
Water
Hyperspectral imaging
Laser
Atomic and Molecular Physics, and Optics
Wavelength
vegetation indices
spectral lenses
business
- Language
- ISSN
- 1424-8220
We propose a novel type of spectral diffractive lenses that operate in the ±1-st diffraction orders. Such spectral lenses generate a sharp image of the wavelengths of interest in the +1-st and –1-st diffraction orders. The spectral lenses are convenient to use for obtaining remotely sensed vegetation index images instead of full-fledged hyperspectral images. We discuss the design and fabrication of spectral diffractive lenses for measuring vegetation indices, which include a Modified Red Edge Simple Ratio Index and a Water Band Index. We report synthesizing diffractive lenses with a microrelief thickness of 4 µm using the direct laser writing in a photoresist. The use of the fabricated spectral lenses in a prototype scheme of an imaging sensor for index measurements is discussed. Distributions of the aforesaid spectral indices are obtained by the linear scanning of vegetation specimens. Using a linear scanning of vegetation samples, distributions of the above-said water band index were experimentally measured.