Instantaneous mapping of liquid crystal orientation using a polychromatic polarizing microscope

Rajabi, Mojtaba; Lavrentovich, Oleg D.; Shribak, Michael

doi:10.1080/02678292.2022.2142883

Cited by 9 publications

(6 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the orientation of retardance, an optical activity based polariscopy method has been developed for anisotropy mapping using true color coding of the orientation. [ 27 ]…”

Section: Resultsmentioning

confidence: 99%

“…For the orientation of retardance, an optical activity based polariscopy method has been developed for anisotropy mapping using true color coding of the orientation. [27] Figure 2 shows a summary of the polarization analysis of a spider silk strand only ≈ 6 μm in diameter using the proposed best fit mode with an additional 𝜆∕4-plate added in front of the sample (retarder). The fit of 4-pol.…”

Section: Retardance and Its Azimuth 𝜹 𝜽 From Fit Of 4-pol Imagesmentioning

confidence: 99%

See 1 more Smart Citation

Determination of Stokes Vector from a Single Image Acquisition

Kamegaki,

Ryu,

et al. 2024

Annalen der Physik

View full text Add to dashboard Cite

Four Stokes parameters (1852) define the polarization state of light. Measured changes of the Stokes vector of light traversing an inhomogeneous sample are linked to the local anisotropies of absorption and refraction and are harnessed over an increasing range of applications in photonics, material, and space/earth observation. Several independent polarization sensitive measurements are usually required for determination of the all four Stokes parameters, which makes such characterization procedure time‐consuming or requires complex setups. Here, a single‐snapshot approach to Stokes polarimetry in transmission is introduced by use of a four‐polarization camera with the on‐chip integrated polarizers. A quarter‐waveplate is added in front of the sample and is illuminated by a linearly polarized light. This approach is demonstrated by measuring birefringence of spider silk of only m‐diameter using microscopy, however, due to its generic nature, it is transferable to other spectral ranges and imaging applications, e.g., imaging from a fast moving satellite or drone or monitoring fast changing events such as phase transitions.

show abstract

“…For the orientation of retardance, an optical activity based polariscopy method has been developed for anisotropy mapping using true color coding of the orientation. [ 27 ]…”

Section: Resultsmentioning

confidence: 99%

Section: Retardance and Its Azimuth 𝜹 𝜽 From Fit Of 4-pol Imagesmentioning

confidence: 99%

Determination of Stokes Vector from a Single Image Acquisition

Kamegaki,

Ryu,

et al. 2024

Annalen der Physik

View full text Add to dashboard Cite

show abstract

“…Thus, the strong correlation between the glass transition temperature and the thermal degradation of silk with its color was experimentally established [ 14 ]. Figure 8 displays several possible optical imaging methods, including the typical transmission mode for intensity to cross-polarized imaging, which can be rendered into a color map of retardance, as well as a mapping of the orientation azimuth [ 16 ]. Silk fibers with structural defects that change the alignment of fibroin along the fiber direction can be observed using transmission mode imaging ( Figure 9 a); however, more detailed structural changes can be revealed using cross-polarized imaging showing localized changes of birefringence and retardance patterns.…”

Section: Resultsmentioning

confidence: 99%

“…Optical microscopy with polarization analysis was used for the optical characterization of the nanostructured surfaces of the spider scales and for silk samples. Emphasis was placed on imaging of the orientation azimuth [ 16 ]. A 4-polarization (4.pol) camera (CS505MUP1, Kiralux Polarization-Sensitive CMOS) was used for the detection of anisotropy in absorbance and retardance ( Figure 1 ).…”

Section: Methodsmentioning

confidence: 99%

Structure and Optical Anisotropy of Spider Scales and Silk: The Use of Chromaticity and Azimuth Colors to Optically Characterize Complex Biological Structures

et al. 2023

Self Cite

View full text Add to dashboard Cite

Herein, we give an overview of several less explored structural and optical characterization techniques useful for biomaterials. New insights into the structure of natural fibers such as spider silk can be gained with minimal sample preparation. Electromagnetic radiation (EMR) over a broad range of wavelengths (from X-ray to THz) provides information of the structure of the material at correspondingly different length scales (nm-to-mm). When the sample features, such as the alignment of certain fibers, cannot be characterized optically, polarization analysis of the optical images can provide further information on feature alignment. The 3D complexity of biological samples necessitates that there be feature measurements and characterization over a large range of length scales. We discuss the issue of characterizing complex shapes by analysis of the link between the color and structure of spider scales and silk. For example, it is shown that the green-blue color of a spider scale is dominated by the chitin slab’s Fabry–Pérot-type reflectivity rather than the surface nanostructure. The use of a chromaticity plot simplifies complex spectra and enables quantification of the apparent colors. All the experimental data presented herein are used to support the discussion on the structure–color link in the characterization of materials.

show abstract

“…Optical microscopy with polarization analysis was used for the optical characterization of the nanostructured surfaces of the spider scales and for silk samples. Emphasis was placed on imaging of the orientation azimuth [16]. A 4-polarization (4.pol) cam-era (CS505MUP1, Kiralux Polarization-Sensitive CMOS) was used for the detection of anisotropy in absorbance and retardance (Figure 1).…”

Section: Optical Imaging Techniquesmentioning

confidence: 99%

Structure and Optical Anisotropy of Spider Scales and Silk: Use of Chromaticity and Azimuth Colors

Linklater¹,

Vailionis²,

Ryu³

et al. 2023

Preprint

View full text Add to dashboard Cite

In this perspective, we give an overview of several less explored structural and optical characterisation techniques useful for biomaterials. New insights into the structure of natural fibres such as spider silk can be gained with minimal sample preparation. Electromagnetic radiation (EMR) over a broad range of wavelengths (from X-ray to THz) provides information of the structure of the material at cor- respondingly different length scales (nm-to-mm). When the sample features, such as the alignment of certain fibres, cannot be characterised optically, polarisation analysis of the optical images can provide further information on feature alignment. The 3D complexity of biological samples necessitates that there be feature measure- ments and characterisation over a large range of length scales. We discuss the issue of characterising complex shapes by analysis of the link between the color and struc- ture of spider scales and silk. For example, it is shown that the green-blue color of a spider scale is dominated by the chitin slab’s Fabry-P ́erot type reflectivity rather than the surface nanostructure. The use of a chromaticity plot simplifies complex spectra and enables quantification of the apparent colors. All the experimental data presented herein are used to support the discussion on the structure-color link in the characterisation of materials.

show abstract

Instantaneous mapping of liquid crystal orientation using a polychromatic polarizing microscope

Cited by 9 publications

References 29 publications

Determination of Stokes Vector from a Single Image Acquisition

Determination of Stokes Vector from a Single Image Acquisition

Structure and Optical Anisotropy of Spider Scales and Silk: The Use of Chromaticity and Azimuth Colors to Optically Characterize Complex Biological Structures

Structure and Optical Anisotropy of Spider Scales and Silk: Use of Chromaticity and Azimuth Colors

Contact Info

Product

Resources

About