Infrared Longpass Filter

Key Features:

  1. Coated on Silicon or Germanium Substrates:
    • Material Options: Available with coatings on either silicon or germanium substrates, offering versatility based on application needs.
  2. Ideal for Isolating Broad Spectral Regions:
    • Application Suitability: Perfect for applications requiring the isolation of broad spectral regions, providing precise control over the wavelength range.
  3. Durable, First-Surface Coatings:
    • Coating Quality: Constructed with hard, durable first-surface dielectric coatings, ensuring longevity and resistance to wear.




Infrared (IR) Longpass Filters Specifications

Parameter Specification
Diameter (mm):  +0.0/-0.1
Cut-On Wavelength (nm):
Operating Temperature (°C): -62 to +71
Surface Quality: 80-50
Thickness Tolerance (mm): ±0.2
Transmission Wavelength (nm):
Type: Longpass Filter
Parallelism (arcmin): <10
Slope Factor (%): <12
Optical Density OD (Average): ≥3.0
Substrate: Silicon (Si)
Coating: Traditional Coated
Thickness (mm):
Transmission (%): >85
Transmission Wavelength (µm):
Blocking Wavelength Range (nm):
Clear Aperture (%): 90
Cut-On Wavelength (µm):
Surface Flatness (P-V): 3 – 5λ
Note: Transmission at cut-on wavelength is 5% of peak transmission.

These general specifications highlight the key parameters and performance characteristics of SHAPE Optics Infrared (IR) Longpass Filters, which are designed for precise optical applications requiring high transmission and effective blocking of unwanted wavelengths, for specific items, please look for our technical support.


  1. Sharp Cut-Off:
    • Wavelength Cut-Off: Provides a sharp cut-off below a specified wavelength, effectively blocking unwanted wavelengths while allowing desired wavelengths to pass through.
  2. High Transmission and Deep Rejection:
    • Performance: Ensures high transmission of desired energy and deep rejection of unwanted energy, making them efficient for precise applications.

Construction and Durability:

  1. Dielectric Coatings:
    • Coating Type: Made with durable dielectric coatings on optical-quality IR-transmitting substrates, ensuring high performance and durability.
  2. Handling and Cleaning:
    • Robustness: Designed to withstand normal cleaning and handling associated with high-quality optical components, ensuring long-term reliability.


  1. FTIR Spectroscopy:
    • Spectroscopy Use: Ideal for Fourier-transform infrared (FTIR) spectroscopy, providing accurate spectral isolation and measurement.
  2. Thermal Imaging:
    • Imaging Systems: Suitable for thermal imaging applications, enhancing the quality and accuracy of thermal images.


  1. Custom Sizes and Coatings:
    • Customization Options: Custom sizes and coating requirements are available. Contact the Sales Department for specific needs and configurations.

For further details and custom inquiries, please reach out to our Sales Department to discuss your specific requirements and get tailored solutions.


Additional information

Weight 0.5 kg
Dimensions 12 × 10 × 8 cm


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