Helpful formulas

Fresnel reflectivity: Fresnel reflectivity with normal incidence in air
Snell’s law:  Snell’s law  
Total reflection: Total reflection  
Brewster’s angle: Brewster’s angle  
Numerical aperture: Numerical aperture  
Free spectral range: Free spectral range n is the refractive index of the cavity and d the cavity gap
Optical density: Optical density
OD T
4 0.01%
3 0.1%
2 1.0%
1 10.0%
Reflectivity finesse: Reflectivity finesse  
Wavenumber:  Wavenumber
λ E
193 nm 51813 cm–1 6.42 eV
355 nm 28169 cm–1 3.49 eV
532 nm 18797 cm–1 2.33 eV
1064 nm 9398 cm–1 1.17 eV
1550 nm 6452 cm–1 0.80 eV
2940 nm 3401 cm–1 0.42 eV
Electron volts: Electron volts
Planck’s constant: Planck’s constant  
Speed of light: Speed of light in vacuum
LO solving equation: LO solving equation  
Mean free path: Mean free path air at room temperature
Temperature:  Temperature  
Pressure:
  mbar Pa atm Torr psi
1 mbar = 1 100 9.87·10–4 0.75 1.45·10–2
1 Pa = 0.01 1 9.87·10–6 7.50·10–3 1.45·10–4
1 atm = 1013 1.01·105 1 760 14.696
1 Torr = 1.33 133 1.316·10–3 1 1.934·10–2
1 psi = 68.95 6895 6.804·10–2 51.71 1