Collection: Infrared (IR) Broadband Pass Filter
• High-performance IR broadband pass filters for 750-1700 nm range
• Excellent transmission and blocking characteristics
• Available in standard and custom sizes
• Ideal for spectroscopy, imaging, and sensing applications
• Compatible with various optical systems and detectors
Infrared (IR) bandpass filters are essential optical components used to isolate specific wavelengths of light in the infrared spectrum. These filters play a crucial role in various applications, including environmental monitoring, security systems, and thermal imaging.
## Introduction to IR Bandpass Filters
IR bandpass filters are designed to transmit a well-defined range of infrared wavelengths while blocking all others. They typically consist of a single substrate with dielectric coatings, making them durable and suitable for use in harsh environments. The filters can be tailored to have center wavelengths ranging from 1.75 µm to 12.00 µm, with bandwidths varying from narrow (less than 1 nm) to wide (a few hundred nanometers).
## Key Specifications
When selecting an IR bandpass filter, several important specifications should be considered:
1. **Center Wavelength (CWL)**: The middle of the transmitting region, typically measured in nanometers.
2. **Full-Width Half-Maximum (FWHM)**: The width of the transmission region at half of the maximum transmission value.
3. **Peak Transmission**: The maximum percentage of light transmitted through the filter.
4. **Cut-on and Cut-off Wavelengths**: The edges of the filter's transmitting region.
5. **Pass Band Ripple**: A measure of how flat the transmitting region is.
6. **Edge Steepness**: The sharpness of the transition between the pass band and the blocked regions.
## Selecting the Right IR Bandpass Filter
When choosing an IR bandpass filter for a specific application, consider the following factors:
1. **Wavelength Range**: Determine the specific IR wavelengths you need to isolate based on your application requirements.
2. **Bandwidth**: Decide whether you need a narrow or wide bandpass filter. Narrowband filters are ideal for isolating specific emission lines, while wideband filters allow a broader range of wavelengths to pass.
3. **Transmission Efficiency**: Look for filters with high peak transmission (typically above 60%) to maximize the amount of desired light passing through.
4. **Blocking Performance**: Consider the out-of-band rejection capabilities of the filter to ensure unwanted wavelengths are effectively blocked.
5. **Environmental Factors**: If the filter will be used in harsh conditions, opt for durable, single-substrate dielectric constructions.
## Applications of IR Bandpass Filters
IR bandpass filters find use in a wide range of applications, including:
1. **Spectroscopy**: Isolating specific spectral lines for analysis in fields such as clinical chemistry and environmental testing.
2. **Thermal Imaging**: Enhancing the performance of Forward-Looking Infrared (FLIR) systems.
3. **Gas Sensing**: Detecting specific gas absorption lines using narrowband filters.
4. **Laser Line Separation**: Isolating particular wavelengths from laser sources.
5. **Fluorescence Applications**: Selectively transmitting excitation or emission wavelengths in fluorescence-based techniques.
By carefully selecting the appropriate IR bandpass filter based on the specific requirements of your application, you can significantly improve the performance and accuracy of your infrared sensing or imaging system.