High-Quality Neutral Density Filters - China Suppliers & Factory for Optical Applications

Introducing our premium Neutral Density Filter, crafted from high transmittance, low dispersion soda lime silicate glass. Manufactured by one of the leading China suppliers, Beijing Jingyi Bo Electro-Optical Technology Co., Ltd., this filter offers exceptional transmission efficiency and is suitable for a wide range of low-color applications. The unique composition of our filters exhibits excellent nonlinear properties, including an increase in refractive index and scattering coefficient with rising temperatures, along with a higher dielectric constant and lower dielectric loss factor. These features contribute to the outstanding nonlinear characteristics of our filters. We offer a variety of neutral density filters, including double-layer double-silver hollow fiber filters with single-sided silver plating, double-sided double-silver filters with hollow fiber and aluminum foil, and double-sided gold-plated hollow fiber filters, all produced in our state-of-the-art factory.

Product Details

Product Overview

The neutral density filter is a kind of optical attenuator, which can attenuate the light intensity. After the light from the visible light region to the near-infrared light region passes through the neutral density filter, different wavelengths are attenuated in the same proportion, so that the optical element is attenuated in the same proportion. The transmittance of light energy is kept approximately equal in the broad band. Also known as neutral density filter, neutral filter, ND filter, attenuation filter, fixed density filter, etc.

Neutral density filters are designed to uniformly reduce transmission over a specific part of the spectrum, and come in two main types, reflective and absorbing. Reflective ND filters consist of thin-film optical coatings, usually metallic, that have been applied to glass substrates. The coating can be optimized for specific wavelength ranges. Thin-film coatings primarily reflect light back to the source. Care needs to be taken to ensure that reflected light does not interfere with the system setup. Absorptive ND filters utilize a glass substrate to absorb a specific percentage of light.

Product Specifications

Wavelength	200–1000 nm
ND	0.1 ～ 4, etc.
Size	Customized according to customer needs

Application Areas

🔬 Ultraviolet measuring instruments
💡 Various lasers
📷 Optical digital cameras & video cameras
📹 Security monitoring systems
🔭 Various optical instruments and equipment
📡 Optical communication attenuation filters
🖼️ Optical imaging systems
💨 Smoke meters
📏 Optical measuring instruments
🧪 Near-infrared spectrometers
🧬 Biochemical analysis equipment

Spectrum

Production Process

Frequently Asked Questions

❓ What is a neutral density (ND) filter and how does it work?

A neutral density filter is an optical attenuator that uniformly reduces the intensity of light across a broad wavelength range — typically from the visible to the near-infrared spectrum (200–1000 nm). It works by attenuating different wavelengths in the same proportion, keeping the transmittance of light energy approximately equal across the band, without altering color or spectral characteristics.

❓ What is the difference between reflective and absorptive ND filters?

Reflective ND filters use thin-film metallic optical coatings applied to glass substrates to reflect light back to the source. They can be optimized for specific wavelength ranges but require careful system setup to avoid interference from reflected light. Absorptive ND filters, on the other hand, use a specially formulated glass substrate that absorbs a specific percentage of incoming light, making them more suitable for applications where reflected light could cause issues.

❓ What ND values are available for neutral density filters?

Our neutral density filters are available in a wide range of optical density (ND) values, from 0.1 to 4.0 and beyond. Each ND value corresponds to a specific level of light attenuation. For example, ND 0.1 transmits approximately 79% of light, while ND 4.0 transmits only 0.01%. Custom ND values can also be produced based on specific application requirements.

❓ Can neutral density filters be customized in size and shape?

Yes. We offer fully customized neutral density filters tailored to customer specifications. Both the size and shape of the filter can be manufactured according to your exact requirements, whether for standard circular, rectangular, or other custom geometries. Please contact our technical team with your specifications for a tailored solution.

❓ What wavelength range do your neutral density filters cover?

Our neutral density filters cover a broad wavelength range from 200 nm to 1000 nm, spanning the ultraviolet (UV), visible, and near-infrared (NIR) regions of the spectrum. This wide coverage makes them suitable for a diverse range of optical instruments and scientific applications, including UV measuring instruments, laser systems, and near-infrared spectrometers.

❓ What industries and applications are neutral density filters commonly used in?

Neutral density filters are widely used across multiple industries and applications, including ultraviolet measuring instruments, laser systems, optical digital cameras, video cameras, security monitoring, optical communication attenuation, optical imaging systems, smoke meters, near-infrared spectrometers, and biochemical analysis equipment. Their ability to uniformly attenuate light without affecting spectral distribution makes them indispensable in precision optical systems.