To make a low-cost and effective infrared polarizer, we designed a mid-infrared polarizer with double-sided silica anti-reflection films. Double-sided silica was oxidized on a silicon substrate. Then, micro gratings were fabricated on silica by using soft nanoimprint lithography and metal thermal evaporation process. The transverse magnetic wave (TM) transmittance exceeds 70% in the wavelength range of 2.56-2.95μm and 3.93-4.97μm. The extinction ratio exceeds 20dB in 2.5-5.5μm band. The mid-infrared polarizer has potential applications in fields such as polarization detection, communication, and spectral analysis.
This study evaluates the polarization state persistence of differently polarized light as they propagate through wet haze (PM2.5), in forward transmission. The investigated wavelength range extends from ultraviolet (UV) to short-wave infrared (SWIR) light. Using a polarization tracking Monte Carlo simulation for a range of particle sizes, wavelengths, relative refractive indices, and propagation distances, we find that both vertically-linearly- and right-handed-circularly-polarized light show superior polarization state persistence at a wavelength of 2.4μm. While the persistence increases gradually for increasing wavelengths, the study also reveals an anomaly, a persistence peak for wet haze with 2μm particles and 0.36μm wavelength. We further compare the polarization state persistence characteristics of vertically linearly and right circularly polarized light. Circular polarization persists better than linear for wet haze in wavelengths of 0.36, 0.543, and 1μm. While with the increase of wavelength and the decrease of particle size, linear polarization gradually persisted better than circular polarization.
KEYWORDS: Light scattering, Scattering, Polarization, Polarimetry, 3D modeling, Photon polarization, Environmental sensing, 3D metrology, Monte Carlo methods, Mie scattering
A three-dimensional (3D) polarimetric tracking model is proposed to calculate scattering interactions between light and media, where a 9×1 coherency or Stokes vector is used to represent the scattered 3D polarized light. Compared with the present Monte Carlo program, this model not only address the continuous rotations problem of the reference plane at least 2 to 3 times, but also realizes the statistics tracking of 3D vibration distribution (i.e., 3D polarization state) for the scattered light in real time. In this paper, we introduce two 3D cartesian coordinate systems: a global coordinate system of an entire scattering environment, and a local coordinate system of a scattering event. Within the proposed 3D polarimetric tracking model, the polarization transformation effect (PTE) related to every scattering event is preciously tracked in corresponding local coordinate system, and the calculated 3D PTE has a 9×9 coherency transformation matrix or Mueller matrix mathematically. Importantly, by utilizing only one rotation of coordinate system, the final 3D polarization transformation effect of an entire scattering environment can be uniquely determined by successive multiplication of all 9×9 matrices characterizing scattering events. The study can be widely applied in several applications of biomimetic polarization navigation, remote sensing, marine surveillance and environmental security to preciously quality the PTE of multitudinous scattering environments.
We fabricated a cost-effective and tractable near-infrared nanowire grid polarizer array with six different directional grating elements on a Borofloat 33 glass substrate at once using a soft nanoimprint and metal thermal evaporation process. Each element consists of a 200-nm period bilayer Al grating with an area of 1.3 × 1.3 mm2. Scanning electron microscopy images reveal that each unit of the polarizer array has an intact nanostructure without large-area damage. Meanwhile, the TM transmittance of each element exceeds 65% in the wavelength range of 1 to 2.5 μm, and of particular note, it is >70 % in the wavelength range of 1.2 to 2.5 μm. The extinction ratio is more than 20 dB in 1.38- to 2.5-μm wavelength range, proving that the polarizer array has good polarization characteristics. Such a polarizer array has low costs and better compatibility with microfabrication processes, which can be used as an element of near-infrared polarization image detection equipment.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.