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Scattering Intensity and Directionality Probed Along Individual Zinc Oxide Nanorods with Precisely Controlled Light Polarization and Nanorod Orientation.

Choi DS, Singh M, Song S, Chang JY, Kang Y, Hahm JI - Photonics (2015)

Bottom Line: We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs.The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices.Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Georgetown University, 37th & O Sts. NW., Washington, DC 20057, USA.

ABSTRACT

We elucidated the light-matter interaction of individual ZnO NRs with a monochromatic beam of linearly polarized light that scatters elastically from the ZnO NRs by performing forward scattering and back-aperture imaging in a dark-field setting. We precisely controlled the electric field vector of the incident light and the NR orientation within the plane of light interaction during both modes of measurement, and spatially resolved the scattering response from different interaction points along the NR long axis. We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs. We identified distinctive scattering profiles from individual ZnO NRs subject to incident light polarization with controlled NR orientation from the forward dark-field scattering and back-aperture imaging modes. The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices. Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

No MeSH data available.


Related in: MedlinePlus

Schematic illustrations showing the experimental setup to measure the NR position- and NR orientation-dependent scattering signal as well as to detect the back-aperture signal from individual ZnO NRs while controlling excitation and collection polarization angles. Three key measurement points in the setup, shown as (i), (ii), and (iii) are displayed in detail inside the boxed panels: (i) sample assembly to achieve refractive index matching for all measurement components and optics, (ii) two distinctive directions for the incoming polarized laser and the two different NR orientations on the measurement plane, and (iii) optical elements to perform forward DF scattering and back-aperture imaging from the same individual NRs. The diagram shown in (ii) is a 180° rotated view of the sample plane and incident light in order to describe the two polarized light directions of E∥ and E⊥. The incident angle of the laser, noted as θin in the diagram, is 62° in our experimental setup. The two orthogonal axes of the sample plane are labelled as x and y. The * sign next to E marks the projected components of the electric field onto the sample plane.
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Figure 1: Schematic illustrations showing the experimental setup to measure the NR position- and NR orientation-dependent scattering signal as well as to detect the back-aperture signal from individual ZnO NRs while controlling excitation and collection polarization angles. Three key measurement points in the setup, shown as (i), (ii), and (iii) are displayed in detail inside the boxed panels: (i) sample assembly to achieve refractive index matching for all measurement components and optics, (ii) two distinctive directions for the incoming polarized laser and the two different NR orientations on the measurement plane, and (iii) optical elements to perform forward DF scattering and back-aperture imaging from the same individual NRs. The diagram shown in (ii) is a 180° rotated view of the sample plane and incident light in order to describe the two polarized light directions of E∥ and E⊥. The incident angle of the laser, noted as θin in the diagram, is 62° in our experimental setup. The two orthogonal axes of the sample plane are labelled as x and y. The * sign next to E marks the projected components of the electric field onto the sample plane.

Mentions: Figure 1 describes our experimental setup to measure forward scattering signals from individual ZnO NRs with controlled orientations. The incoming light source, a linearly polarized 642 nm laser, was passed through a half-lambda (HL) plate at 45° and 90° to control the orientation of the incident electric field (E) vector to achieve E∥ (polarization direction lying in the plane of incidence) and E⊥ (polarization direction perpendicular to the plane of incidence) orientations, respectively. After passing through a series of mirrors and neutral density filters, the laser beam was directed to the sample stage via a dark field (DF) condenser with a high numerical aperture. The use of DF in our setup is essential to resolve the inherently low amount of signal to be collected from individual NR samples. As displayed in panel (i) of Figure 1, multiple components involved in the ZnO NR sample assembly are refractive index-matched throughout all existing interfaces, and this configuration allows for total internal reflection (TIR) of the incident laser beam after illuminating the sample.


Scattering Intensity and Directionality Probed Along Individual Zinc Oxide Nanorods with Precisely Controlled Light Polarization and Nanorod Orientation.

Choi DS, Singh M, Song S, Chang JY, Kang Y, Hahm JI - Photonics (2015)

Schematic illustrations showing the experimental setup to measure the NR position- and NR orientation-dependent scattering signal as well as to detect the back-aperture signal from individual ZnO NRs while controlling excitation and collection polarization angles. Three key measurement points in the setup, shown as (i), (ii), and (iii) are displayed in detail inside the boxed panels: (i) sample assembly to achieve refractive index matching for all measurement components and optics, (ii) two distinctive directions for the incoming polarized laser and the two different NR orientations on the measurement plane, and (iii) optical elements to perform forward DF scattering and back-aperture imaging from the same individual NRs. The diagram shown in (ii) is a 180° rotated view of the sample plane and incident light in order to describe the two polarized light directions of E∥ and E⊥. The incident angle of the laser, noted as θin in the diagram, is 62° in our experimental setup. The two orthogonal axes of the sample plane are labelled as x and y. The * sign next to E marks the projected components of the electric field onto the sample plane.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643738&req=5

Figure 1: Schematic illustrations showing the experimental setup to measure the NR position- and NR orientation-dependent scattering signal as well as to detect the back-aperture signal from individual ZnO NRs while controlling excitation and collection polarization angles. Three key measurement points in the setup, shown as (i), (ii), and (iii) are displayed in detail inside the boxed panels: (i) sample assembly to achieve refractive index matching for all measurement components and optics, (ii) two distinctive directions for the incoming polarized laser and the two different NR orientations on the measurement plane, and (iii) optical elements to perform forward DF scattering and back-aperture imaging from the same individual NRs. The diagram shown in (ii) is a 180° rotated view of the sample plane and incident light in order to describe the two polarized light directions of E∥ and E⊥. The incident angle of the laser, noted as θin in the diagram, is 62° in our experimental setup. The two orthogonal axes of the sample plane are labelled as x and y. The * sign next to E marks the projected components of the electric field onto the sample plane.
Mentions: Figure 1 describes our experimental setup to measure forward scattering signals from individual ZnO NRs with controlled orientations. The incoming light source, a linearly polarized 642 nm laser, was passed through a half-lambda (HL) plate at 45° and 90° to control the orientation of the incident electric field (E) vector to achieve E∥ (polarization direction lying in the plane of incidence) and E⊥ (polarization direction perpendicular to the plane of incidence) orientations, respectively. After passing through a series of mirrors and neutral density filters, the laser beam was directed to the sample stage via a dark field (DF) condenser with a high numerical aperture. The use of DF in our setup is essential to resolve the inherently low amount of signal to be collected from individual NR samples. As displayed in panel (i) of Figure 1, multiple components involved in the ZnO NR sample assembly are refractive index-matched throughout all existing interfaces, and this configuration allows for total internal reflection (TIR) of the incident laser beam after illuminating the sample.

Bottom Line: We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs.The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices.Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Georgetown University, 37th & O Sts. NW., Washington, DC 20057, USA.

ABSTRACT

We elucidated the light-matter interaction of individual ZnO NRs with a monochromatic beam of linearly polarized light that scatters elastically from the ZnO NRs by performing forward scattering and back-aperture imaging in a dark-field setting. We precisely controlled the electric field vector of the incident light and the NR orientation within the plane of light interaction during both modes of measurement, and spatially resolved the scattering response from different interaction points along the NR long axis. We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs. We identified distinctive scattering profiles from individual ZnO NRs subject to incident light polarization with controlled NR orientation from the forward dark-field scattering and back-aperture imaging modes. The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices. Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

No MeSH data available.


Related in: MedlinePlus