What is Ultra Narrow Bandpass Filter

Ultra-narrow bandpass filters are optical narrowband filters that permit only a very narrow wavelength band to pass through while blocking all light outside the passband. Their bandwidth is typically extremely narrow, ranging from 1 to 3 nm, with some ultra-narrow passbands reaching below 0.1 nm. These ultra-narrow bandpass filters are commonly used in applications such as laser line selection, spectral analysis, or fluorescence detection.
Coligh is a Chinese manufacturer of ultra-narrow bandpass filters. Utilizing a multilayer dielectric film structure and ion-assisted coating technology, we produce a variety of ultra-narrow bandpass filters spanning wavelengths from ultraviolet to short-wave infrared. These filters feature a half-bandwidth of 0.5-3nm, ensuring a transmission rate of ≥85% while maintaining a cutoff depth of OD4 or even OD6 beyond the passband. We currently maintain multiple inventory options available for sample testing.

Why Choose Coligh’s Ultra Narrow Hard Coated Bandpass Filter

We currently stock ultra-narrowband bandpass filters with multiple wavelengths and half-bandwidths. We also offer custom filter services with half-bandwidths ranging from 0.5 to 3nm based on customer requirements. Reasons to choose us:

1. We employ ion-assisted deposition and ion beam sputtering for vapor deposition. Our hard-coating process ensures more stable and dense films, guaranteeing long-term precision and stability of the center wavelength.
2. We currently achieve stable production of filters with a half-bandwidth of 0.5nm, featuring high yield rates. We can also customize filters with narrower half-bandwidths to meet specific customer needs.
3. Through optimized film system design, most ultra-narrowband filters achieve over 90% transmittance, with a conservative minimum of ≥85%.
4. Hard coating technology ensures strong adhesion between the film and substrate, delivering high hardness and abrasion resistance.
   We offer flexible customization of center wavelength, bandwidth, shape, dimensions, and substrate materials to meet specific client requirements.
5. Every filter leaving our facility undergoes rigorous monitoring via spectrometers and high-precision spectrophotometers. Our filters exhibit exceptional consistency, with spectral parameters maintaining high uniformity across batches and production runs.

Example Of Ultra Narrow Bandpass Filter–1550.1/2nm

Example Of Blocking depth Of 1550.1/2nm Ultra Narrow Bandpass Filter

 

Coligh Ultra Narrow Bandpass Filter Stock List

Ultra Narrow Optical Bandpass Filter Applications

• LiDAR
  LiDAR systems require strict matching of laser wavelengths, necessitating extremely narrow-bandpass filters. Ultra-narrow-bandpass filters allow only wavelengths perfectly matched to the laser’s own wavelength to reach the detector while blocking stray ambient light. This enhances the radar signal-to-noise ratio, enabling LiDAR operation under intense illumination and extending detection range.
• Raman Spectroscopy Detection
  Raman spectroscopy detection requires illuminating samples with high-energy lasers. The emitted light consists of extremely low-energy Raman scattered light. Ultra-narrow-band pass filters can extract this faint scattered light from the laser background, enabling Raman instruments to detect samples with low concentration levels.
• Astronomical Observation
  Stars and nebulae emit light at specific wavelengths, but this light is obscured by atmospheric glow and urban light pollution. Ultra-narrowband bandpass filters selectively transmit light from target celestial bodies while filtering out background light, enabling the capture of astronomical images with exceptional contrast.