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Wide-field mid-infrared (MIR) hyperspectral imaging offers a promising approach for studying heterogeneous chemical systems due to its ability to independently characterize the molecular properties of different regions of a sample. However, applications of wide-field MIR microscopy are limited to spatial resolutions no better than ∼1 μm. While methods exist to overcome the classical diffraction limit of ∼λ/2, chromatic aberration from transmissive imaging reduces the achievable resolution. Here we describe the design and implementation of a simple MIR achromatic lens combination that we believe will aid in the development of resolution-enhanced wide-field MIR hyperspectral optical and chemical absorption imaging. We also examine the use of this doublet lens to image through polystyrene microspheres, an emerging and simple means for enhancing spatial resolution.
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Ultraviolet hyperspectral microscopy using chromatic-aberration-based iterative phase recovery
Ultraviolet (UV) microscopy has recently re-emerged as an important label-free, molecular imaging technique. This stems from the unique UV absorption properties of many endogenous biomolecules that play a critical role in cell structure and function. However, broadband hyperspectral imaging in this spectral region is challenging due to strong chromatic aberrations inherent in UV systems. Here we apply an intensity-based, two-stage, iterative phase-recovery algorithm that leverages the same chromatic aberrations to overcome this challenge. Importantly, knowledge of samples’ dispersion or absorption properties is not required. We demonstrate that the computationally retrieved phase can be applied to digitally refocus images across a large bandwidth. This enables hyperspectral UV imaging with a simple microscope for quantitative molecular analysis. We validate this method through simulations and through experiments with red blood cells.
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- Award ID(s):
- 1752011
- PAR ID:
- 10148271
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 45
- Issue:
- 10
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 2708
- Size(s):
- Article No. 2708
- Sponsoring Org:
- National Science Foundation
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