Visible 300-700nm Neutral Density Filters

Definition:

A visible neutral density filter (ND Filter) is a filter that reduces or modifies the amount of light transmitted in a system, usually across a specified range. These filters often require a near flat transmission level across the band. A common example would be sunglasses to reduce transmission/glare from sunlight. Neutral density filters are also be used to protect optical detectors from damage due to over exposure within a system, failure to do this can result in reduced instrument lifetime.

Design and Manufacture:

We design and manufacture Neutral Density Filters across the visible range between 300 nanometres to 700 nanometres to any custom specification. Please refer to our Infrared neutral density filter page for neutral density filters from 700 – 6000nm.

Supplying Optics:

We hold an extensive inventory of stock wafer substrates, including Glass, Sapphire, Silicon, Germanium, Fused Silica, Calcium Fluoride, and more, available in various thicknesses and ready for immediate coating. Post-coating, these substrates can be swiftly diced, or core drilled, significantly reducing lead times, often to less than two weeks. Additionally, we have a network of trusted optics suppliers, whom we regularly audit, to provide custom optics. This allows us to offer a comprehensive solution, delivering the coated filter as a complete package from a single supplier, simplifying your procurement process.

Coat Only Service:

We also provide an express coating service for customer-supplied optics, with typically a 1 week turnaround so if you already have the optics, we are more than happy to coat them for you. With hundreds of different-sized tooling jigs, accumulated over years of manufacturing, so we can often save on both tooling costs and lead times by utilising or modifying existing tooling to suit your requirements.

Please contact us to discuss your specific requirements.

Case Studies

Visible ND Filters 75%, 50%, 25%

Visible ND Filter 10%

Applications

Laser Optics:

ND filters are used to reduce the intensity of laser beams in research labs, allowing for safe examination and manipulation of the beams without damaging sensitive equipment. In industrial applications, such as material processing or medical devices, ND filters help in calibrating laser systems by providing consistent attenuation.

Microscopy:

ND filters are used to control the intensity of light sources to prevent photobleaching and photodamage to samples. This is particularly important in biological research where delicate specimens are studied.

Spectroscopy:

ND filters are employed to adjust the intensity of light used to illuminate samples, ensuring accurate and consistent measurements in spectroscopic analysis.

Detector Protection:

Neutral Density Filters are used to protect sensitive detectors from being saturated or damaged by high-intensity light sources.

Optical Instrumentation:

In the calibration of optical sensors and cameras, ND filters are used to simulate different lighting conditions and ensure accurate sensor responses. ND filters are also part of quality control processes in the manufacturing of optical components, ensuring that products meet specified performance criteria under various lighting conditions.

Aerospace:

In satellite imaging and remote sensing, ND filters help to manage the intensity of reflected sunlight, improving the quality and accuracy of captured images.

Medical Imaging:

ND filters are used in diagnostic equipment to control light exposure on the patient’s eye, ensuring safe and comfortable examination conditions.

Industrial Inspection and Machine Vision:

In automated inspection systems, ND filters are used to regulate the light intensity, ensuring consistent lighting conditions for accurate defect detection. They also improve image quality in machine vision applications by controlling the exposure and enhancing the contrast of images captured under varying lighting conditions.