Variables and Constants

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	first order hyperpolarizability (microscopic) (beta)
cos3θ	order parameter
δ	Two photo 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 Cofficient Pockels Effect r~ 10-12 – 1—10 m/V
r33	Electro-optic cofficient (chi 33)(FM= 1000 pm/V)
χ2	second-order nonlinear susceptiblity (first order hyperpolarizability) (macroscopic)
χ3	third-order nonlinear susceptiblity (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	Fluoresence 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