LiDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging) is a sensing technology that measures the distance, shape, and properties of objects by emitting laser beams and receiving reflected signals. The working principle of LiDAR is based on the “Time of Flight” (ToF) method, which involves generating laser pulses, emitting them, and receiving their reflections to calculate the distance and position of the target object.
Optical systems commonly used in LiDAR include lenses and filters, which are essential for focusing, diffusing, and modulating laser signals. When used together, filters and lenses ensure the precise and consistent execution of the laser’s light path. Optical filters in LiDAR systems allow specific laser wavelengths to pass through while blocking sunlight and other environmental light, thereby improving the signal-to-noise ratio.
Applications of LiDAR Optical Filters
- LiDAR Mapping: High-precision terrain data collection for creating accurate 3D terrain models.
- Automotive LiDAR: Environmental perception for autonomous vehicles, enabling obstacle detection, path planning, and collision avoidance.
- Aerospace LiDAR: Remote sensing applications for satellites and aircraft.
- Architecture and Urban Planning: Generating 3D models of buildings and infrastructure.
- Forestry Management: Assessing vegetation height and density.
- Security and Surveillance: Intrusion detection and target recognition.
- Augmented Reality (AR) and Virtual Reality (VR): Providing precise environmental perception data.
Common LiDAR Narrow Bandpass Filter Wavelengths
- 532nm: Green lasers for specialized mapping or underwater detection (effective underwater transmission).
- 780nm or 830nm: Used in certain small LiDAR sensors.
- 905nm (Near-Infrared): Widely applied in automotive LiDAR, consumer devices, and medium-to-short-range measurements.
- 940nm (Near-Infrared): Ideal for robots, drones, or compact vehicle systems for environmental sensing.
- 1064nm: Commonly used in laser rangefinders or airborne remote sensing LiDAR systems, particularly in terrain mapping.
- 1550nm (Mid-Infrared): Suitable for long-distance measurement and high-performance LiDAR systems (e.g., advanced autonomous vehicle systems).
Custom LiDAR Optical Filter Requirements for Manufacturers
- Precise Center Wavelength Matching
For wavelengths like 905nm or 940nm, the tolerance typically needs to be within ±2nm to maximize transmittance and signal qualityon the LiDAR detector. - Bandwidth Control
Narrow bandwidth filters are often required to strictly filter specific wavelengths, such as 10nm or smaller (e.g., 5nm or even 0.4nm). Narrow bandwidth is particularly effective in suppressing background light in environments with high solar or stray light interference. - High Transmission Rates
LiDAR systems generally demand a transmittance of >90% at the target wavelength, with some systems requiring >95% or even 98% to ensure maximum signal transmission and minimal loss. - Wide Incident Angle Stability
Some LiDAR systems require receiving signals from various angles. Filters with a wide incident angle range (e.g., 0°-45°) are critical while maintaining stable transmission and center wavelength performance.
Why Coligh LiDAR Custom thin film optical filter stands out?
Unique features of Coligh FIlter
The Coligh LiDAR Optical Filter sets itself apart with its advanced engineering and exceptional performance. Its unique features ensure your LiDAR systems operate with unmatched precision and reliability.
High Transmission Rates
Coligh filters achieve transmission rates exceeding 95%, allowing maximum signal capture. This ensures your LiDAR system collects stronger signals, enhancing detection accuracy and extending measurement range.
Narrow Bandwidths
These filters are tailored to meet specific system requirements with bandwidths as narrow as less than 1 nm. This precision improves the clarity of the laser signal, enabling your system to focus solely on the desired wavelengths.
Deep Blocking Capabilities
Coligh filters minimize interference from ambient light by providing deep blocking capabilities. This feature ensures that background noise does not compromise the accuracy of your measurements, even in environments with bright sunlight or artificial lighting.
Wide Angle
Coligh can provide filters with an incident angle range of 0-60°and keep high transmission at the target wavelength at the same time.
Environmental Stability
Designed for durability, Coligh filters maintain performance under challenging conditions. They resist temperature fluctuations, humidity, and physical shocks, ensuring reliable operation across diverse applications.
You can rely on Coligh filters to deliver precise and consistent results, even in challenging environments. Explore Coligh’s innovative solutions today to enhance the efficiency and accuracy of your LiDAR systems.
