High-Quality Long-Pass Interference Filters from China Suppliers and Factory - Steep Blocking & High Transmittance

High-Quality Long-Pass Interference Filters from China Suppliers and Factory - Steep Blocking & High Transmittance

The long-pass filter is a crucial optical component widely used in various applications within the optics field. Its primary function is to allow long-wave light to pass through while effectively blocking short-wave light.

At Bodian Co., Ltd., a leading manufacturer and supplier based in China, we pride ourselves on our experienced R&D team dedicated to developing high-quality optical filters. Our long-wave filters boast high transmittance, substantial cut-off depth, and a steep transition band capable of cutting off short-wavelength light down to 200nm. Additionally, our filters exhibit excellent film integrity, making them reliable for diverse applications.

Our long-pass filters are extensively utilized in research experiments, analytical instruments, fluorescence testing equipment, environmental monitoring tools, agricultural measuring devices, biochemical instruments, and medical analysis sectors. As a reputable factory, we offer a wide range of long-pass filters in stock, with options for customization to meet any specific customer requirements.

Product Details

Product Overview

Long-wave filter is called in the digital photography industry, and its optical characteristics are same, that is, the light in the long-wave direction is highly transmitted, while the light in the relatively short-wave direction is cut off. It belongs to a type of cut-off filter. Of course, the long-wave filter used in optical precision instruments, its cut-off filter. Depth is more demanding than photographic filters, and its quality is higher. The long-wave filter is made of special colored glass, and the dopant in the material absorbs the spectrum of a specific band but transmits the long-wave band. These filters are absorbing filters and are not suitable for use under laser conditions.

Product Specifications

ProcessIon Assisted Dura
Wavelength (nm)LP320, 420, 435, 455, 475, 495, 510, 530, 550, 570, 590, 610, 630, 665, 695, etc.
Average Transmittance>90%
Steepness50%～OD5 < 10nm
Cutoff DepthOD>6
Size (mm)Φ25.4, 70×70

Application Areas

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Long-pass filters are mainly used in biometric identification, optical fiber lighting, strong light flashlights, medical testing instruments, beauty photonic equipment, multi-band detectors, stage lighting systems, cold light source display cabinets, digital imaging applications and other fields and industries.

Parameter	Specification
Process	IAD Hard Coating
Wavelength	LP320, 420, 435, 455, 475, 495, 510, 530, 550, 570, 590, 610, 630, 665, 695, etc.
T avg.	>90%
Slope	50%～OD5 < 10nm
Blocking	OD>6
Size	Φ25.4, 70×70

Spectrum

Production Process

Frequently Asked Questions

❓What is a long-pass filter and how does it work?

A long-pass filter (LP filter) is an optical filter that transmits light with wavelengths longer than a specified cut-on wavelength while blocking shorter wavelengths. It works by using specially doped colored glass whose material absorbs specific short-wave spectral bands while allowing long-wave light to pass through with high transmittance.

❓What wavelengths are available for your long-pass filters?

Our long-pass filters are available in a wide range of cut-on wavelengths, including LP320, 420, 435, 455, 475, 495, 510, 530, 550, 570, 590, 610, 630, 665, 695 nm, and more. Custom wavelengths can also be discussed upon request.

❓What coating process is used for these long-pass filters?

These filters are manufactured using Ion Assisted Deposition (IAD) Hard Coating technology. This process ensures high durability, excellent adhesion, and superior optical performance compared to conventional coating methods.

❓Are long-pass filters suitable for use with lasers?

No. Long-pass filters made from specially doped colored glass are absorbing filters. They are not suitable for use under laser conditions, as the absorbed energy can cause thermal damage to the filter. For laser applications, alternative filter types with reflective coatings are recommended.

❓What are the typical applications of long-pass filters?

Long-pass filters are widely used across many industries, including biometric identification systems, optical fiber lighting, high-intensity flashlights, medical diagnostic instruments, beauty and photonic devices, multi-band detectors, stage lighting systems, cold light source display cabinets, and digital imaging applications.

❓What sizes are available for the long-pass filters?

Standard sizes available include Φ25.4 mm (circular) and 70×70 mm (square). Custom sizes can be accommodated based on specific project requirements. Please contact us for more details on custom sizing options.