Linear Variable Neutral Density Filter

Description

1.  Features

• Precise Light Attenuation: Allows controlled attenuation of light, making it ideal for laser and white light applications.
• Linear Density Shift: Provides a linear variation in optical density across the filter for smooth light modulation.
• Versatile Use: Suitable for both white light and laser systems.
• High Optical Quality: Manufactured from premium optical materials, ensuring clear performance and accuracy.
• Customization Available: SOT offers tailored solutions for specific wavelength ranges and optical specifications.

2. General Description

The Linear Variable Neutral Density (LVND) Filter is a specialized optical component used to control the intensity of light by varying the filter’s optical density along its surface. As the filter is shifted, it linearly attenuates the light, making it ideal for applications that require smooth and consistent modulation of light intensity. These filters are particularly useful in laser systems and applications involving white light, where precise control of light intensity is essential.

The linear attenuation can be achieved by translating two filters in opposite directions, allowing for fine control over the light attenuation. SOT manufactures these filters with exceptional surface quality, linear density shift, and parallelism, ensuring reliable performance for both standard and customized optical needs. B270 and fused silica are commonly used as substrates for these filters, providing high optical clarity and stability. The standard wavelength range for these filters is typically from 380 to 2000 nm with coatings designed for fused silica and B270 substrates.

3. Spectrum Transmission Curves

SOT offers customized services for the spectrum transmission curves to meet your specific application requirements. If our standard components do not meet your needs, we can provide a tailored solution based on the desired wavelength range, attenuation level, and optical performance.

4. Coating Quality

• Adhesion Test: Compliant with MIL-C-675C military standards, involving a tape that meets LT-90 specifications, applied to the lens film layer. The tape was affixed and removed vertically three times, with no blistering or peeling.
• Temperature Test: Following MIL-C-675C standards, the filters were subjected to temperatures of -62±1℃ and 71±1℃. The adhesion test was repeated after maintaining at room temperature for 2 hours, confirming no detachment.
• Abrasion Resistance Test: According to MIL-C-675C and CCC-C-440 standards, gauze testing with a force of 1.0 lbs (0.45 kg) was conducted. No damage was observed after 25 repetitions.
• Humidity Test: Conducted under MIL-C-675C standards, exposure to 49±2℃ and 95-100% humidity for 24 hours showed no defects.
• Solvent and Cleaning Testing: Exposed to acetone and alcohol for 10 minutes each. After air drying and cleaning, no peeling or scratches were observed.
• Salt Spray Test: After 100 hours in 35°C with 5% saltwater concentration, the film showed no signs of damage.

5. Standard Specifications

6. General Applications and Examples

Linear Variable Neutral Density Filters find applications in numerous optical systems that require gradual attenuation of light. Some of the primary use cases include:

• Laser Systems: Used to modulate laser intensity for fine-tuning power in systems such as laser cutting, welding, and engraving.
• White Light Applications: Employed in optical experiments and instruments where controlled attenuation of light intensity is necessary.
• Optical Testing and Measurement: Helps in precise optical testing where light intensity needs to be adjusted without affecting other optical properties of the system.
• Camera and Sensor Systems: Used to ensure that light levels are within optimal ranges for sensors and cameras.
• Spectroscopy: In applications where precise light attenuation is required to avoid overexposure or to control the spectrum intensity for various experimental conditions.

7. SOT Strengths and Capabilities

Shape Optics Technologies Pte Ltd (SOT) excels in manufacturing high-performance optical filters and components, including Linear Variable Neutral Density Filters. SOT is committed to providing tailored solutions that meet the exact requirements of our customers. Our expertise in coating technology, coupled with high-precision fabrication capabilities, ensures that our filters consistently meet the most stringent standards for performance and reliability. With a dedicated focus on quality and custom solutions, SOT delivers cutting-edge optical products for diverse industries, including laser systems, scientific research, and optical testing.

8. Standard Products