Longpass Filters

A Longpass Filter, a type of optical bandpass filter, is designed to transmit light of longer wavelengths than the cuton wavelength while obstructing or attenuating shorter wavelengths. Commonly utilized in photography, spectroscopy, microscopy, and sensor technologies, these filters are critical components in numerous optical applications.

Features：

• Precision Cuton Wavelength: Our custom longpass filters are engineered with precise cuton wavelengths tailored to specific applications, ensuring optimal performance in selective wavelength transmission.
• Advanced Coating Techniques: Utilizing state-of-the-art coating technologies, our filters exhibit superior blocking capabilities for shorter wavelengths while allowing the desired longer wavelengths to pass through effectively.
• High Transmission and Steep Transition: These filters offer high transmission rates for the longer wavelengths with steep transitions between the transmission and blocking regions, enhancing the clarity and quality of the transmitted light.
• Versatile Material Options: We provide longpass filters made from a variety of substrate materials, such as glass, fused silica, and specialized optical polymers, to suit different operational environments and requirements.
• Robust and Durable: Our filters are designed for durability, ensuring reliable performance even in demanding conditions. They are resistant to environmental factors such as temperature fluctuations and humidity.
• Custom Dimensions and Shapes: Longpass filters can be customized in various dimensions and shapes to fit specific instruments and setups, providing flexibility and ease of integration.

Applications：

1. Optical Experiments and Spectral Analysis

• Spectral Separation: In optical experiments, it is often necessary to separate light of different wavelengths. Longpass filters effectively block shorter wavelengths and allow only longer wavelengths to reach detectors or imaging devices, facilitating spectral separation.
• Fluorescence Detection: In fluorescence spectroscopy, longpass filters are used to block excitation light and transmit only fluorescence signals, enhancing the accuracy of spectral measurements.
• Raman Spectroscopy: They can also be employed to block Rayleigh scattering light and improve the signal-to-noise ratio of Raman scattering signals.

2. Biomedical Imaging and Analysis

• Fluorescence Microscopy: As optical lenses for fluorescence microscopy, longpass filters help enhance image contrast and clarity by blocking excitation light and transmitting other non-fluorescent light.
• Biochemical Detection: They are utilized in the detection of fluorescently labeled substances such as proteins and nucleic acids, crucial for biochemical analyses.

3. Infrared Imaging and Thermography

• Infrared Imaging Systems: In infrared imaging, longpass filters block visible light and short-wave infrared light, transmitting only long-wave infrared light, enabling infrared imaging.
• Thermography: They are employed in thermography instruments to block ambient temperature radiation and transmit only infrared radiation emitted by target objects, facilitating temperature measurement and imaging.

4. Materials Science and Research

• Semiconductor Characterization: Longpass filters are used in the characterization and measurement of semiconductor materials, as well as in analyzing the luminescence properties of materials.
• Fluorescent Material Testing: They assist in measuring the fluorescence intensity and spectra of fluorescent materials.

5. Environmental Monitoring

• Atmospheric Pollutant Monitoring: Longpass filters are applied in monitoring atmospheric pollutants, such as measuring the infrared radiation characteristics of aerosols and particulates.
• Oceanographic Research: They are also used in oceanographic monitoring to measure seawater temperature, salinity, and other parameters.

6. Other Applications

• Geological Exploration: They are employed in measuring the infrared radiation characteristics of rocks and soils to infer their composition and properties.
• Food Safety Detection: In food processing, longpass filters can detect fluorescent substances such as fluorescent brighteners in food products.
• Spectral Separation: In optical experiments, it is often necessary to separate light of different wavelengths. Longpass filters effectively block shorter wavelengths and allow only longer wavelengths to reach detectors or imaging devices, facilitating spectral separation.
• Fluorescence Detection: In fluorescence spectroscopy, longpass filters are used to block excitation light and transmit only fluorescence signals, enhancing the accuracy of spectral measurements.
• Raman Spectroscopy: They can also be employed to block Rayleigh scattering light and improve the signal-to-noise ratio of Raman scattering signals.

Kingwin Optics provides comprehensive support and design services for custom longpass filters, ensuring that your specific application requirements are met with precision and efficiency.