470 nm

• Mittlere Wellenlänge von 470 nm im tiefblauen Spektrum
• Anwendungen in LED-Beleuchtung, blauen Lasern, Optogenetik und wissenschaftlicher Forschung
• Verschiedene Filteroptionen mit unterschiedlichen FWHM-Bereichen (10 nm bis 135 nm)
• Bandpassfilter mit einer Mittenwellenlänge von 470 nm erhältlich
• Die Preise liegen zwischen 25 und 115 US-Dollar für verschiedene Filterspezifikationen

470nm Filter Application Selection Guide

1. Fluorescence Microscope Excitation Optical Path Configuration

In fluorescence imaging systems, 470nm filters primarily excite specific fluorophores such as GFP variants or Cy2 dyes. Taking GFP as an example, its excitation spectrum includes a secondary peak at 470nm, which can achieve efficient separation of excitation and emission light when paired with a long-pass dichroic mirror.

Core Configuration Requirements:

  1. Excitation Filter:
  • Central wavelength: 470nm
  • Bandwidth: 10–20nm (e.g., ET470/40x)
  • Transmittance: >90%
  • Blocking depth: OD6+Narrow bandwidth ensures only 470nm excitation light passes through, minimizing stray light interference with fluorescence signals.
  1. Dichroic Mirror:
  • Reflectance range: 430–460nm
  • Transmittance range: 485–800nm (e.g., T505lp)
  • Incidence angle: 45°
  • Reflectivity: >95%Spectral splitting directs excitation light to the sample while transmitting longer-wavelength fluorescence signals.
  1. Emission Filter:
  • Central wavelength: 525nm
  • Bandwidth: 50nm (e.g., ET525/50m)
  • Transmittance: >85%
  • Blocking depth: OD4+Selectively filters emission light to suppress residual excitation light and background noise.

Key Considerations for Selection:

  • Bandwidth Control: Narrower excitation filter bandwidths improve light purity, reducing non-specific fluorophore excitation. For example, a 10nm bandwidth filter effectively distinguishes 470nm excitation from adjacent wavelengths like 488nm.
  • Blocking Depth: OD6+ blocking attenuates stray light to less than 0.0001% of original intensity, significantly enhancing signal-to-noise ratio—critical for detecting weak fluorescence signals.
  • Material Compatibility: Substrates like B270 glass or fused silica reduce optical distortion and thermal expansion effects, suitable for long-term imaging applications.

2. Water Quality Nitrate Detection Optical System

In UV absorption-based water monitoring, 470nm filters eliminate secondary wavelength interference from deep-UV LED sources. For instance, 235nm LEDs generate approximately 10% intensity of 470nm secondary light that must be blocked by filters.

Core Configuration Requirements:

  1. Bandpass Filter:
  • Central wavelength: 470nm
  • Bandwidth: 5–10nm
  • Transmittance: >85%
  • Blocking range: 350–460nm & 480–1100nm
  • Blocking depth: OD4+Narrowband design precisely filters out 470nm secondary light, preventing it from entering the detection optical path.
  1. Long-Pass Filter:
  • Cutoff wavelength: 470nm
  • Transmittance: >480nmSeparates excitation light (235nm) from detection signals (275nm). For example, an LP470nm filter reflects 235nm excitation light while transmitting 275nm detection light.

Key Considerations for Selection:

  • Secondary Light Suppression: OD4+ blocking depth reduces 235nm LED secondary light intensity to below 0.01%, ensuring detection signal accuracy.
  • Dual-Wavelength Synergy: Combining 235nm (nitrate absorption peak) and 275nm (organic matter absorption peak) detection, the 470nm filter isolates secondary light, enabling the formula c(NO₃⁻-N) = k×(Abs235 - α×Abs275) + b to eliminate organic interference.
  • Environmental Adaptability: Anti-corrosive coatings (e.g., TiO₂/SiO₂ composite films) withstand chemical substances in water, extending filter service life.

3. Selection Considerations

  1. Spectral Matching: Choose filter bandwidth based on light source characteristics (e.g., LED full width at half maximum). A blue LED with 20nm FWHM requires a 20–30nm bandwidth filter to avoid spectral truncation and light intensity loss.
  2. Incidence Angle Effect: Central wavelengths of dichroic mirrors and bandpass filters shift with incidence angle (e.g., 45° angle may cause 5–10nm red shift). Select products compatible with the optical path design angle.
  3. Cost-Benefit Balance: Magnetron sputtering coated filters (e.g., Chroma AT series) offer better blocking depth and durability than vacuum evaporation coatings but at higher cost—choose based on application requirements.

By following these configurations, 470nm filters achieve high-purity excitation in fluorescence imaging and effective interference suppression in water quality detection, significantly enhancing system performance.

Nachricht an uns