Open AccessHigh-NA achromatic diffractive lensing for arbitrary dual-wavelengths enabled by hybridized metal-insulator-metal cavities
Author(s) -
Chenjie Dai,
Shanhong Wan,
Rui Yang,
Zejing Wang,
Chengwei Wan,
Yangyang Shi,
Jian Zhang,
Zhongyang Li
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.399213
Subject(s) - achromatic lens , optics , lens (geology) , lithography , wavelength , optoelectronics , materials science , physics
A new type of diffractive lens based on hybridized Fabry-Perot (FP) cavities with high-NA and achromatic features for arbitrary dual-wavelengths is theoretically proposed and demonstrated. We utilize the subwavelength-scale metal-insulator-metal nanocavity to form a Fresnel zone plate (MIM-FZP) that benefits from both spectral selectivity and high numerical aperture (NA > 0.9) to enable lensing functionality. By taking advantage of the different transmission orders from MIM, any arbitrary dual-wavelength achromatic focusing design is achieved. Using this approach, we merge two independent MIM-FZP designs and realize achromatic focusing performance at the selected dual-wavelength of 400/600 nm. Furthermore, the achromatic lens also exhibits a crucial potential for dynamically tuning of the operation wavelengths and focusing lengths as actively scaling the core layer thickness of MIM. The unique MIM-FZP design can be practically fabricated using a grayscale lithography technique. We believe such high-NA and achromatic optical devices enjoy great simplicity for structural design and can easily find applications including high-resolution imaging, new-generation integrated optoelectronic devices, confocal collimation, and achromatic lens, etc.