Long-pass 470nm orange-yellow coated optical lens for photon hair removal filter.

Basic Characteristics and Core Parameters of LP470nm Filter

The LP470nm filter is a long-pass optical filter designed to transmit light with wavelengths greater than 470nm while blocking shorter wavelengths. Depending on the application, its optical specifications may vary slightly. Typical parameters include:

• Transmission Wavelength: The primary range spans from 470nm to 1100nm (for beauty device applications) up to 475nm to 1200nm (for general optical uses), with some products extending into the near-infrared region up to 1500nm.
• Blocking Performance: The blocking range typically covers 350nm to 450nm (or 200nm to 450nm), with a blocking depth reaching OD2 (for beauty devices) to OD4-OD6 (in fluorescence detection scenarios), effectively blocking ultraviolet and short-wavelength blue light.
• Transmittance: Peak transmittance is generally above 90%, and with anti-reflection coatings, some products can achieve up to T94%, ensuring efficient light throughput.

Material Selection and Process Features of LP470nm Filter

The material and manufacturing process of this filter directly influence its optical performance and suitability for various applications:

• Common Substrates: These include K9 glass (low-cost, general-purpose), quartz (high-temperature resistant, high transmittance), and sapphire, with specialized applications sometimes using infrared materials like calcium fluoride or zinc selenide.
• Coating Technology: Employing high-temperature evaporation combined with ion source-assisted deposition, a durable hard coating is formed to enhance wear resistance and service life. Some products undergo double-sided polishing to ensure optical flatness and parallelism.
• Custom Shapes: Supports circular (φ5~150mm), square (2x2~150x150mm), and custom-shaped processing, with thickness ranging from 0.21mm to 5mm, meeting installation requirements for various devices.

Typical Application Fields of LP470nm Filter

Due to its spectral characteristics, the LP470nm filter is widely used in multiple fields:

• Beauty Devices: As a core optical component, it is used in whitening, spot removal, and hair removal equipment to filter harmful short-wavelength light while transmitting therapeutic light above 470nm, enabling safe and effective photobiomodulation.
• Fluorescence Detection and Analysis: In systems such as PCR fluorescence excitation, it works alongside band-pass filters to create customized spectral channels, improving detection signal-to-noise ratio.
• Photography and Optical Imaging: Reduces long-wavelength interference in LED lighting imaging to enhance image contrast; used in astronomical observations to isolate specific wavelength bands of starlight.