Laser Brightness Calculator
Calculate laser radiance and compare brightness between different laser wavelengths
Calculate Laser Brightness
Calculate Radiance
Find laser brightness (radiance) for a single laser
Compare Brightness
Compare brightness between two different lasers
Laser Parameters
Total optical power output of the laser
Laser wavelength in nanometers (380-700 nm visible range)
Laser Brightness Results
Laser Radiance
Perceived Brightness
Key Formulas: L = P/λ², Lλ = P × phλ, Beam ratio includes λ⁴ Rayleigh scattering
Note: Calculations based on human eye photopic response (555nm peak sensitivity)
Brightness Analysis
📏 Good visibility - moderate eye sensitivity
🌟 Optimal for laser pointers - green is most visible to human eye
Example Calculation
Green Laser Pointer (532nm, 100mW)
Power: P = 100 mW = 0.1 W
Wavelength: λ = 532 nm = 532 × 10⁻⁹ m
Radiance: L = P/λ² = 0.1/(532×10⁻⁹)² = 3.53 × 10¹¹ W/m²·sr
Photopic factor: ph₅₃₂ = 0.862 (86.2% eye sensitivity)
Dot brightness: 0.1 × 0.862 × 683 = 58.9 lm
Comparison: Green vs Red Laser
• Green (532nm, 100mW): 58.9 lm dot brightness
• Red (650nm, 100mW): 7.3 lm dot brightness
• Green appears 8.1× brighter to human eye
• Beam scattering ratio: Green is 4.2× more visible in air
Eye Sensitivity by Wavelength
Based on CIE photopic luminosity function
⚠️ Laser Safety
Never look directly into laser beam
Avoid pointing at reflective surfaces
Use appropriate safety glasses
High power lasers require special handling
Follow local regulations for laser use
Understanding Laser Brightness
What is Laser Brightness?
Laser brightness, scientifically called radiance, measures the amount of optical power emitted per unit area per solid angle. It's a fundamental property that determines how bright a laser appears and how effectively it can deliver energy to a target.
Why Wavelength Matters
- •Human eye sensitivity varies dramatically with wavelength
- •Green lasers (532nm) appear brightest to human vision
- •UV and IR lasers are invisible but can be dangerous
- •Rayleigh scattering affects beam visibility in air
Key Formulas
- L = P / λ² (Radiance)
- Lλ = P × phλ (Dot Brightness)
- Beam Ratio = (L₁/L₂) × (λ₂⁴/λ₁⁴)
- Lumens = P × phλ × 683
- L: Radiance (W/m²·sr)
- P: Laser power (W)
- λ: Wavelength (m)
- phλ: Photopic conversion factor
- 683: Luminous efficacy constant
Applications and Considerations
Laser Pointers
Green lasers (532nm) are preferred for presentations due to maximum eye sensitivity and visibility in various lighting conditions.
Industrial Applications
High-power lasers for cutting and welding prioritize power density over visibility, often using IR wavelengths for efficiency.
Scientific Research
Specific wavelengths are chosen for material interaction, fluorescence excitation, or atmospheric transmission properties.