Wire Grid Polarizer

The highly efficient Harrick Wire Grid Polarizer consists of a wire grid that is holographically deposited onto a KRS-5 substrate. This polarizer has a wide spectral range from 5000 cm-1 to 285 cm-1. The thin profile of this polarizer makes it convenient for applications in which there are space constraints.

The general-purpose model is mounted into a fully 0° to 360° rotatable slide plate. Accessory-specific configurations of this polarizer are designed to fit the Harrick Seagull, VariGATR/GATR, and FastIR accessories.

Applications

Ideal for removing interference fringes from transmission spectra recorded at Brewster’s angle.
Excellent for obtaining optimum sensitivity for reflectance measurements.

VIEW FEATURES, AND INCLUDES

Ordering Information	Catalog Number
Wire Grid Polarizer, 0-360°	PWG-U1R
Wire Grid Polarizer, 0 and 90° for the Seagull (includes slide plate mount)	PWG-SEA
Wire Grid Polarizer, 0 and 90° for the FastIR (includes slide plate mount)	PWD-FAS-XXX*
Wire Grid Polarizer, 0 and 90° for the VariGATR and GATR (includes slide plate mount)	PWD-GATR-XXX*
*XXX indicates spectrometer make and model.

VIEW ORDERING INFORMATION

VIEW ADDITIONAL INFORMATION

Additional Information

The Wire Grid Polarizer consists of regularly spaced thin strips of parallel conductive wires. When the polarizer is placed perpendicular to the incoming radiation, the wires transmit the component of the electric field that is perpendicular to the wires, and reflect the component parallel to the wires.

The efficiency of a wire grid polarizer depends on the conductivity of the wire and also on the ratio of the grid spacing (d) to the wavelength of interest (λ). In theory, all types of parallel grids are efficient polarizers when the ratio of the grid spacing to the wavelength of interest (d/λ) is <<1. In practice, good agreement is obtained between measured and theoretical values when d/ λ <0.5 and when higher conductivity wires are used.

Polarizer performance is generally characterized by:

K1: The transmission efficiency for normal incidence polarized light whose electric field vector is perpendicular to the wires, also known as the wanted component. For a perfect polarizer, K1=1.
K2: The transmission efficiency for normal incidence polarized light whose electric field vector is parallel to the wires, also known as the unwanted component. For a perfect polarizer, K2=0.

Other commonly used measures of performance deduced from K1 and K2 are the degree of polarization or efficiency and the extinction ratio, whose formulas are shown in Table 1.

Table 1: Wire Grid Polarizer (KRS-5 substrate) Specifications.

Grid Period (µm)

0.25

% Transmission Efficiency (K₁)

2.5µm

5µm

10µm

% Transmission of Unwanted
Radiation (K₂)

2.5µm

5µm

10µm

1.5

0.5

0.23

% Degree of Polarization

2.5µm

5µm

10µm

95.8

98.8

99.7

Extinction Ratio

2.5µm

5µm

10µm

23:1

84:1

160:1

Maximum Temperature (ºC)

110

Our Wire Grid Polarizer offers high efficiency in a compact form. With its holographically deposited wire grid on a KRS-5 substrate, it is suitable for use from 5000cm-1 to 285cm-1. Table 1 summarizes its specifications. The transmission efficiency from the wanted and unwanted components, in addition to the degree of polarization and extinction ratio, from a typical polarizer are shown in Figures 1 and 2 respectively. Note that there are some artifacts from the manufacturing process that appear as absorption bands in the wanted component (K1, Table 1).

PWG Wanted and Unwanted Components

Figure 1. Transmission efficiency for the wanted (K1) and unwanted (K2) components of a typical wire grid polarizer (KRS-5 substrate).

PWG Polarizer Efficiency

Figure 2. Degree of polarization (efficiency) and extinction ratio of a typical wire grid polarizer (KRS-5 substrate).

Wire Grid Polarizer Data Sheet

Applications

Features

Additional Information