1. Features
- High transmission rate: ≥90% transmission for the majority of the wavelength range.
- Strong optical density: Optimal optical density to suppress stray light and enhance signal quality.
- Low temperature shift: Excellent stability across a wide temperature range.
- Versatile applications: Suitable for a variety of industries, including industrial optics, scientific research, and laser systems.
- Customizable: Filters can be tailored to meet specific wavelength, optical density, or transmittance requirements.
2. General Description
Narrow bandpass filters are optical filters designed to transmit light within a narrow range of wavelengths and block light outside that range. These filters are essential in various applications, including optical communication, laser systems, and spectrometry. SOT’s narrow bandpass filters offer excellent performance with high transmittance rates and low temperature shifts, making them ideal for use in environments where precision and stability are crucial. These filters are manufactured to ensure consistent performance across different temperature ranges and environmental conditions. Available in a broad selection of wavelengths, our filters can be customized to meet specific customer requirements, ensuring optimal functionality for a wide range of optical systems.
3. Spectrum Transmission Curves
If the standard components are not available, customized solutions are available upon request to meet your specific requirements. Our narrow bandpass filters can be tailored to your wavelength and optical density needs.
4. Coating Quality
- Adhesion Test: Compliant with MIL-C-675C military standards, the adhesion test involves applying a tape that meets LT-90 specifications onto the lens film layer. The tape is affixed fully and then removed vertically. This procedure is performed three times, resulting in no blistering or peeling.
- Temperature Test: In line with MIL-C-675C specifications, test pieces are subjected to temperatures of -62±1°C and 71±1°C. After maintaining them at room temperature (16°C~32°C) for two hours, the adhesion test is repeated, confirming no film detachment.
- Abrasion Resistance Test: Conforming to MIL-C-675C and CCC-C-440 standards, the abrasion resistance test involves a gauze tester applying a minimum force of 1.0 lbs (0.45 kg) to the film. This is repeated 25 times with gauze widths of 1/4 inch (6.4mm) and 3/8 inch (9.5mm), ensuring no damage occurs to the film surface.
- Humidity Test: Under MIL-C-675C criteria, the test piece is placed in a controlled temperature and humidity chamber set to 49 ±2°C and 95%~100% humidity for 24 hours. The film remains intact, with no peeling, scratches, or other defects.
- Solvent and Cleaning Testing: Following MIL-C-675C specifications, test pieces are exposed to room temperature conditions (16°C~32°C) and tested with acetone and alcohol for at least 10 minutes each. After air drying and subsequent cleaning with a cotton cloth soaked in alcohol, the film surface shows no signs of peeling or scratches.
- Salt Spray Test: After 100 hours in a 35°C environment with a 5% saltwater concentration, the film shows no signs of damage.
5. Standard Specifications
| Model | CWL (nm) | Transmittance | FWHM (nm) | Optical Density | Notes |
| NH-BP250 | 250±5 | T≥70% | 10-20 | OD≥3@300-400 | Standard model |
| NH-BP315 | 315±2 | T≥70% | 10-20 | OD≥3@300-400 | Customization available |
| NH-BP320 | 320±2 | T≥60% | 10-20 | OD≥3@300-1100 | For industrial use |
| NH-BP340 | 340±2 | T≥60% | 10-20 | OD≥3@300-1100 | Available on request |
| NH-BP375 | 375±2 | T≥90% | 10-20 | OD≥3@300-1100 | High precision model |
| NH-BP405 | 405±2 | T≥90% | 10-20 | OD≥3@350-1100 | Common wavelength |
| NH-BP445 | 445±2 | T≥90% | 10-20 | OD≥3@350-1100 |
6. General Applications and Examples
Narrow bandpass filters are widely used in several fields:
- Laser Systems: In laser applications, these filters are used to transmit specific wavelengths of light while blocking out unwanted background wavelengths. They ensure the purity of the laser signal for optimal performance.
- Spectrometry: They help isolate narrow regions of the electromagnetic spectrum for accurate analysis in spectrometers.
- Industrial and Scientific Research: These filters find applications in industrial imaging systems, scientific instruments, and optical testing systems, enhancing the precision of optical measurements.
- Astronomical Imaging: Narrow bandpass filters are used in telescopes to isolate light from specific wavelengths emitted by celestial objects, improving image quality by rejecting unwanted light pollution.
7. SOT Strengths and Capabilities
Shape Optics Technologies Pte Ltd (SOT) is a leader in manufacturing precision optical components. We specialize in the production of high-quality narrow bandpass filters that meet stringent customer specifications. Our facilities incorporate advanced technologies and rigorous quality control processes to ensure the highest standards of reliability and performance. Whether you’re in need of standard solutions or customized options, SOT is committed to delivering filters that enhance the accuracy and functionality of your optical systems.
8. Standard Products
Standard Products for Narrow Bandpass Filters:
| Model | CWL (nm) | Transmittance | FWHM (nm) | Optical Density | Notes |
| NH-BP250 | 250±5 | T≥70% | 10-20 | OD≥3@300-400 | Standard model |
| NH-BP315 | 315±2 | T≥70% | 10-20 | OD≥3@300-400 | Customizable |
| NH-BP320 | 320±2 | T≥60% | 10-20 | OD≥3@300-1100 | For industrial use |
| NH-BP340 | 340±2 | T≥60% | 10-20 | OD≥3@300-1100 | Available on request |
| NH-BP375 | 375±2 | T≥90% | 10-20 | OD≥3@300-1100 | High precision model |
| NH-BP405 | 405±2 | T≥90% | 10-20 | OD≥3@350-1100 | Common wavelength |
| NH-BP445 | 445±2 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP460 | 460±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP470 | 470±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP490 | 490±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP520 | 520±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP532 | 532±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP540 | 540±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP550 | 550±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP565 | 565±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP590 | 590±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP650 | 650±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP710 | 710±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP750 | 750±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP800 | 800±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP850 | 850±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP940 | 940±3 | T≥90% | 10-20 | OD≥3@350-1100 | |
| NH-BP1680 | 1680±10 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP1940 | 1940±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2000 | 2000±3 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2050 | 2050±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2180 | 2180±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2230 | 2230±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2270 | 2270±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2310 | 2310±2 | T≥90% | 10-20 | OD≥3@800-3000 | |
| NH-BP2500 | 2500±2 | T≥90% | 10-20 | OD≥3@800-3000 |
Additional Notes:
- Customization: Parameters such as optical density, transmittance, and FWHM can be customized to fit specific requirements. If your needs fall outside the standard offerings, please reach out to SOT for tailored solutions.
