Variables and Constants
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Common
| Symbol | Meaning |
|---|---|
| c | speed of light (c = 299,792,458 m/s approx 3 x 106m/s) |
| ν | frequency |
| h | planck's constant (h = 6.62606896x 10-34 J s = 4.135667 x 10-15eV s) |
| λ | wavelength (visible spectrum is 400-700nm) |
Absorption and Emission
| Symbol | Meaning |
|---|---|
| ε | extinction coefficient of a molecule |
| Φ | quantum yield |
| Ψ | wave function |
EO Properties
| Symbol | Meaning |
|---|---|
| μ | dipole moment (mu) measured in debyes |
| α | linear polarizability (alpha) |
| β | molecular first hyperpolarizability (microscopic) (beta) |
| γ | molecular second hyperpolarizability (microscopic) (gamma) |
| cos3θ | order parameter |
| δ | Two-photon cross section measured in Goppert-Mayer units (GM), with 1 GM=1×10-50 cm4 s molecules−1 photon−1 >100gm is high.) |
| r | Pockels coefficient or Linear Electo-optic Coefficient Pockels Effect r~ 10-12 – 1—10 m/V |
| r33 | Electro-optic coefficient (chi 33)(FM= 1000 pm/V) |
| χ2 | second-order nonlinear susceptibility (first order hyperpolarizability) (macroscopic) |
| χ3 | third-order nonlinear susceptibility (second order hyperpolarizability) (macroscopic) (alpha)(FM= 6-7 x 10-21(m/V)2) |
| ε | dielectric constant or relative static permittivity |
| M | Transition dipole moment (measured in debyes) |
| N | Number Density parameter |
| φfl | Fluorescence Quantum Yield a ratio of photons absorbed over photons emitted |
| σ | conductivity (measured in S (Siemens)/cm |
| t | the electronic coupling, transfer integral or resonance integral |
| vπ | half-wave driving voltage |
Devices
| Symbol | Meaning |
|---|---|
| α | material loss in dB/cm |
| d | electrode separation |
| Γ | optical electrical overlap |
| λ | reorganization energy |
| μ | charge mobility in cm2 / V s- a mobility >1 is considered good |
see also Wikipedia Greek Letters in Science