Collection: Infrared (IR) Longpass Filter
- **High-performance IR longpass filters** with cut-on wavelengths from 2200nm to 9000nm.
- **Optical density (OD)** of 2 across specified blocking ranges up to 8000nm.
- **Substrate options** include Czochralski Silicon P Type for excellent IR transmission.
- **Ideal applications** include thermal imaging, FTIR spectroscopy, and remote sensing.
- **Available in larger formats** (100mm to 150mm diameter) for specialized IR needs.
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Dimension
For IR filters, we usually supply in larger format. (Dia100mm to Dia150mm).
Price is also significantly higher than bandpass filter in VIS range. -
Substrates
Silicon (Si)
Silicon is a popular substrate material for IR longpass filters due to its high transmission in the infrared range. It is often used in applications such as FTIR spectroscopy and thermal imaging
Germanium (Ge)
Germanium is another widely used substrate material for IR longpass filters. It offers excellent transmission properties in the infrared spectrum and is durable, making it suitable for various optical applications
Sapphire
Sapphire can also be used as a substrate for IR filters, particularly for applications requiring high durability and resistance to harsh environments. However, it is less common for longpass filters compared to silicon and germanium
Thermal Imaging and Remote Sensing
IR longpass filters are essential in thermal imaging applications to block visible light and shorter wavelength infrared radiation, allowing only thermal radiation with longer wavelengths to pass through. This is critical for capturing high-quality thermal images in applications such as building inspections, electrical inspections, and predictive maintenance.
FTIR Spectroscopy
These filters are ideal for Fourier Transform Infrared (FTIR) spectroscopy, where they help isolate broad regions of the infrared spectrum. They provide high transmission of desired energy and deep rejection of unwanted energy, making them efficient for precise spectroscopic measurements.