Product description
Mono-crystalline silicon infrared filters are based on mono-crystalline silicon wafers substrates. By alternately depositing optical films with different refractive indices and thicknesses on the substrate, they achieve the function of filtering specific infrared wavelengths.
Core principle
Mono-crystalline silicon offers excellent infrared transmission, particularly in the 1.2–7 μm and far-infrared ranges. By integrating this property with coating processes, various spectral control functions can be realized—such as long-pass, short-pass, bandpass, anti-reflection, and reflective coatings. In this way, only the desired infrared wavelengths are transmitted, while unwanted wavelengths are effectively suppressed.
Typical applications
Infrared thermometers, pyroelectric sensors, gas analyzers, night vision instrument windows, thermal imaging equipment, etc. They are also known as special filter films for infrared sensors.
Product Models list:
| No. | Product Name | CWL / Transmittance / FWHM | Out-of-Band Rejection | Typical Applications |
| 1 | 4260 nm IR Narrowband Filter | CWL: 4260 nm @ T > 70~80% FWHM: 90~380 nm | UV ~ 11 μm @ T > 1% | CO₂ detection, flame alarms, carbon dioxide alarms |
| 2 | 3900 nm IR Narrowband Filter | CWL: 3900 nm @ T > 70~80% FWHM: 90~170 nm | UV ~ 11 μm @ T < 1% | Methane detectors, gas alarms |
| 3 | 3350 nm IR Narrowband Filter | CWL: 3350 nm @ T > 70% FWHM: 120 nm | UV ~ 11 μm @ T < 1% | Methane (CH₄) detection |
| 4 | 3470 nm IR Narrowband Filter | CWL: 3470 nm @ T > 70% FWHM: 125 nm | UV ~ 11 μm @ T < 1% | Automotive exhaust gas detection |
| 5 | 3570 nm IR Narrowband Filter | CWL: 3570 nm @ T > 70% FWHM: 125 nm | UV ~ 11 μm @ T < 1% | Alcohol detection |
| 6 | 5640 nm IR Narrowband Filter | CWL: 5640 nm @ T > 75% FWHM: 230 nm | UV ~ 11 μm @ T < 1% | Alcohol detection |
| 7 | 4650 nm IR Narrowband Filter | CWL: 4650 nm @ T > 75% FWHM: 225 nm | UV ~ 11 μm @ T < 1% | Carbon monoxide (CO) detection |
| 8 | 5050 nm IR Narrowband Filter | CWL: 5050 nm @ T > 75% FWHM: 205 nm | UV ~ 11 μm @ T < 1% | Carbon monoxide (CO) detection |
| 9 | 7350 nm IR Narrowband Filter | CWL: 7350 nm @ T > 75% FWHM: 225 nm | UV ~ 11 μm @ T < 1% | Sulfur dioxide (SO₂) detection |
| 10 | 8–14 μm IR Bandpass Filter | Passband: 9~13 μm @ T > 70% | UV ~ 20 μm @ T < 1% | Temperature detection, electronic thermometers, etc. |
| 11 | 5.5 μm Long-Pass IR Filter | 5~14 μm @ T > 78% | UV ~ 4 μm @ T < 1% | Temperature detection, automatic sensing equipment, IR light switches |
| 12 | 6.5 μm Long-Pass IR Filter | 7~14 μm @ T > 78% | UV ~ 6 μm @ T < 1% | Temperature detection, automatic sensing equipment, IR alarms |
| 13 | 3–5 μm IR Anti-Reflection (AR) Coating | Average transmittance T > 80% in 3~5 μm | — | IR anti-reflection applications (transmittance varies slightly with substrate thickness) |
| 14 | 8–14 μm IR Anti-Reflection (AR) Coating | Average transmittance T > 80% in 8~14 μm | — | IR anti-reflection applications (transmittance varies slightly with substrate thickness) |
Remark:
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Shenzhen Hengda Liyuan Optoelectronics introduced advanced optical technology that apply depositing nanomaterials through ion-assisted evaporation onto a multilayer hard film in a high vacuum environment which coating layer is firm and has good tightness, and small bandwidth drift. Liyuan optoelectronics have been focus on optical coating for more than 17 years and offer one-stop optical filters solution including Narrow Bandpass Filters, IR cut-off Filters, Longpass & Short Filters, Notch Filters, ND filters, Star filters and Optical sapphire block.
