WP25H-C
CaF₂ Holographic Wire Grid Polarizer, Ø25 mm, Mounted
Quantity
Key Highlights
CaF₂ substrate for excellent transmission in the infrared region.
Holographic wire-grid polarizer designed for broadband IR polarization applications.
Ø25 mm (1") optic for integration into standard optical systems.
Ø18 mm clear aperture provides a large usable optical area.
Provides high polarization selectivity across a broad infrared wavelength range.
Typical extinction ratio: approximately 100:1 at 3 µm and 250:1 at 8 µm.
Mounted configuration provides convenient handling and integration into optical setups.
Suitable for applications requiring linear polarization control and analysis in the mid-IR.
Available as part of Thorlabs' family of holographic wire-grid polarizers using different IR-transparent substrates.
Description
The Thorlabs WP25H-C is a Ø25 mm CaF₂ holographic wire-grid polarizer designed for controlling and analyzing the polarization state of infrared radiation. The polarizer uses a holographically produced wire-grid structure to selectively transmit one linear polarization component while attenuating the orthogonal polarization. This makes it particularly useful for broadband infrared applications where conventional visible-wavelength polarizers may not provide suitable transmission or operating bandwidth. The calcium fluoride (CaF₂) substrate provides excellent infrared transmission and is well suited for applications involving wavelengths extending into the mid-infrared region. Thorlabs specifies typical extinction ratios of approximately 100:1 at 3 µm and 250:1 at 8 µm, demonstrating its ability to discriminate between orthogonal polarization states across the IR spectrum. The optic has a 25 mm outer diameter and 18 mm clear aperture, and the polarizer is supplied in a mounted configuration for convenient installation in laboratory optical systems. Thorlabs lists the WP25H-C as a CaF₂ Holographic Wire-Grid Polarizer, Mounted. Compared with standard visible/NIR linear polarizers, the WP25H-C is especially advantageous for infrared spectroscopy, thermal imaging, IR laser systems, and polarization-sensitive measurements.
Specifications
Product Type: Holographic Wire-Grid Polarizer Part Number: WP25H-C Polarizer Type: Holographic Wire-Grid Substrate Material: Calcium Fluoride (CaF₂) Optic Diameter: 25.0 mm (Ø1") Clear Aperture: Ø18 mm Mounting: Mounted Typical Extinction Ratio at 3 µm: 100:1 Typical Extinction Ratio at 8 µm: 250:1 Operating Region: Infrared/Mid-IR Polarization: Linear Outer Mount Diameter: Ø25 mm The extinction-ratio values above are typical values reported by Thorlabs rather than a single guaranteed value across the complete operating range. Thorlabs lists the CaF₂ version at approximately 100:1 at 3 µm and 250:1 at 8 µm.
Application
The WP25H-C is suitable for a wide range of infrared polarization applications, including:
Mid-IR Polarization Control
Infrared Spectroscopy
IR Laser Systems
Thermal Imaging
Infrared Imaging Systems
Polarization Analysis
IR Optical Measurements
Fourier Transform Infrared (FTIR) Systems
Remote Sensing
Gas Detection and Spectroscopy
Infrared Microscopy
Scientific and Research Optical Systems
Polarization-Sensitive Detection
Free-Space Infrared Optical Systems
The WP25H-C is particularly suitable when an experiment requires broadband linear polarization in the infrared region, especially in systems operating around the 3–8 µm range, where its CaF₂ substrate and wire-grid structure provide useful IR transmission and polarization discrimination.