Optical Cavity Calculator
Enter cavity length and mirror reflectivities. The Optical Cavity Calculator instantly computes free spectral range, finesse, linewidth, Q-factor, and photon lifetime.
About the Optical Cavity Calculator
The Optical Cavity Calculator is a precise, scientifically accurate tool that computes all key parameters of a Fabry-Pérot optical cavity (resonator) using the standard formulas from laser physics and quantum optics. This Optical Cavity Calculator implements the exact expressions for free spectral range (FSR), finesse, linewidth, Q-factor, and photon lifetime — essential for laser design and spectroscopy. Proudly supported by Agri Care Hub.
Scientific Formulas
Finesse: F = π √(r₁ r₂) / (1 - r₁ r₂)
Linewidth (FWHM): Δν = FSR / F
Q-factor: Q = ν₀ / Δν
Photon Lifetime: τ = Q / (2π ν₀)
Why This Calculator Is Essential
Optical cavities are fundamental in: • All lasers (defining modes and gain) • Gravitational wave detectors (LIGO) • Optical frequency combs and atomic clocks • Cavity quantum electrodynamics (cQED) • High-resolution spectroscopy • Optical filters and sensors The finesse and Q-factor determine cavity performance, linewidth, and enhancement of light-matter interaction.
How to Use
- Enter cavity length L in meters (round-trip path).
- Enter resonance wavelength λ in nm.
- Enter mirror reflectivities R₁ and R₂ in %.
- Click “Calculate Optical Cavity”.
When Should You Use This Tool?
- Laser cavity design and mode analysis
- Optical resonator engineering
- Precision spectroscopy
- Gravitational wave detector modeling
- Quantum optics and cQED
- Teaching laser physics and resonators
Scientific Foundation
Optical cavities (Fabry-Pérot resonators) were invented in 1899. The formulas are derived from multiple-beam interference and are exact for plane waves. Finesse and Q are standard figures of merit in optics. Full theory at Optical Cavity on Wikipedia and Siegman’s *Lasers* (1986).
Conclusion
The Optical Cavity Calculator brings professional resonator engineering tools to your browser — with perfect accuracy and beautiful design. Whether you’re a student learning laser physics, a researcher designing high-finesse cavities, or an engineer building optical systems, this tool delivers precise results every time. For more optics tools, visit Agri Care Hub.