Neutral density filters (ND filters) are core optical components that attenuate light intensity without altering the energy distribution of the spectrum, and they can be widely applied in various fields such as natural light and lasers. The fixed neutral density filters produced by Ultraopto Optoelectronic Technology Co., Ltd., with their exquisite craftsmanship and strict quality control, achieve uniform attenuation of light intensity across a wide spectral range. Their surfaces are coated with durable metal films, ensuring strong stability and wide adaptability, meeting the usage requirements of various optical systems, especially suitable for the calibration work of optical systems.
Product Categories
The fixed density filters produced by the company are mainly divided into two categories, which can be flexibly selected according to different application scenarios.
Absorption and reflection type density plate:
It has dual attenuation characteristics of both absorption and reflection, achieving neutral attenuation within a wide spectral range, and is suitable for various complex optical path scenarios.
Low reflection density filter (ND filter):
With a low reflection design, it effectively reduces light path reflection interference and has excellent attenuation uniformity, making it suitable for scenarios with high requirements for light path purity.
Product advantages
Spectral neutrality:
While attenuating light intensity, it does not alter the spectral energy distribution, ensuring the accuracy of optical measurements and imaging, and there is no spectral distortion.
Wide-spectrum compatibility:
It can achieve uniform attenuation within a wide spectral range, compatible with various light sources such as natural light and lasers, and has a wide range of applications.
Strong durability: The surface is coated with high-quality metal film layers, which are wear-resistant, resistant to strong light, and immune to environmental interference. The performance remains stable over a long period of use, and the service life is long.
Precise matching:
Good attenuation consistency, especially suitable for precise scenarios such as optical system calibration and optical power calibration.
Customization flexibility:
According to the specific requirements of customers, density plates of special sizes, optical densities, and working wavelengths can be customized to fit various non-standard optical systems.
Typical application fields
Optical system calibration and alignment
Laser power attenuation and protection
Image system light intensity adjustment
Spectral measurement and precision detection experiments
Optical fields related to industrial vision, scientific research experiments, etc.
Ultraopto Optoelectronic Technology Co., Ltd. specializes in the research and development, production and customized services of precision optical components. With years of in-depth experience in the optical field, we possess mature coating processes, a strict quality control system and a professional technical team. We always take customer needs as the core and provide high-quality and highly reliable optical solutions for the fields of laser, imaging, spectroscopy, scientific research and industrial optics, helping customers achieve technological upgrades and product optimization
Ultraopto’s Neutral Density (ND) Filter is a high-precision optical filter designed to uniformly attenuate the intensity of all wavelengths of light without altering hue or color rendition, serving as an essential component in photography, laser power control, optical metrology and high-brightness imaging systems. Crafted from premium optical-grade glass substrates with high-quality metal-dielectric or solid-state absorption coatings, our ND Filters deliver wavelength-independent light attenuation across the UV, visible and NIR spectral ranges, with minimal spectral distortion and high transmittance uniformity (<2% variation) to ensure accurate light intensity control without affecting color balance or spectral characteristics. The filters are available in a wide range of optical densities (OD), from OD0.3 (50% transmittance) to OD4.0 (0.01% transmittance), with precise OD accuracy of ±0.05 to meet diverse light attenuation requirements, from mild dimming to extreme light reduction for high-brightness light sources.
Manufactured with advanced vacuum coating technology and precision optical processing, our Neutral Density Filters achieve superior surface quality with an 80-50 scratch-dig rating and a clear aperture of over 90%, with scratch-resistant and durable coatings that withstand frequent cleaning and long-term use in both laboratory and industrial environments. We offer two core types: reflective ND filters with metal-dielectric coatings for high laser damage threshold and transmission ND filters with solid-state absorption coatings for uniform attenuation and minimal back reflection, with both types available in standard and custom sizes, including circular, square and rectangular shapes to match different optical system integration needs. The filters feature excellent mechanical and environmental stability, with coatings resistant to temperature changes, humidity and chemical corrosion, ensuring consistent attenuation performance over time and in complex working conditions. For laser applications, our high-power ND filters are engineered with a high laser damage threshold (≥10J/cm² for pulsed lasers) to withstand high-intensity laser irradiation without coating degradation or damage.
Our Neutral Density Filters are widely applied in a diverse range of professional and industrial fields, including photography and videography where they enable slow shutter speeds and large apertures in bright light conditions to create motion blur effects and shallow depth of field, and laser systems for precise laser power control and beam attenuation to protect optical components and detectors from high-intensity laser radiation. In optical metrology and scientific research, the filters are used for calibrating light detectors, adjusting light source intensity and conducting high-precision optical experiments with controlled light levels, while in industrial machine vision and high-brightness imaging systems, they reduce light intensity to prevent overexposure of image sensors and ensure clear, high-contrast imaging. They are also essential in solar energy research, display technology and aerospace optical sensors for light intensity control in high-brightness environments.
As a professional manufacturer of precision optical filters, Ultraopto offers fully customized Neutral Density Filter solutions to meet your unique light attenuation requirements. Our experienced R&D and engineering team can tailor optical density values, spectral ranges, substrate materials (optical glass, fused silica) and filter dimensions, with custom coating designs for high-power laser applications, low-reflection requirements or ultra-broad spectral ranges. We also provide custom mounting options and anti-reflection coatings to further enhance optical performance and integration ease.
All custom ND Filter orders undergo multi-stage strict optical performance testing and quality inspection, including transmittance/attenuation measurement, spectral uniformity verification and laser damage threshold testing (for high-power models), with a detailed quality inspection report provided to ensure the final product fully complies with your design specifications and application needs. Backed by advanced optical coating technology, a complete quality control system and stable batch supply capacity, Ultraopto is committed to providing global customers with high-quality Neutral Density Filter products and comprehensive optical filter solutions. For more detailed technical parameters, product quotation information or custom design solutions for our Ultraopto Neutral Density Filter, please contact our professional sales and technical team through the official website, and we will provide you with efficient, professional and personalized optical solutions to support the development and production of your optical systems and devices.
