# plask.phys¶

Basic physical constants and utility functions.

## Constants¶

 qe Elementary charge [C] me Electron mass [kg] c Speed of light [m/s] mu0 Vacuum permeability [V·s/(A·m)] eps0 Vacuum permittivity [pF/µm] eta0 Free space impedance [Ω] Z0 Free space impedance [Ω] h.J Pnav-sidenavlanck constant [J·s] h.eV Planck constant [eV·s] SB Stefan-Boltzmann constant [W/(m2·K4)] kB.J Boltzmann constant [J/K] kB.eV Boltzmann constant [eV/K]

## Functions¶

 eV2nm(eV) Compute wavelength for specified photon energy. nm2eV(nm) Compute photon energy for specified wavelength. wl(mat, lam[, T]) Compute real length of optical wavelength in specified material.

## Descriptions¶

### Function Details¶

plask.phys.eV2nm(eV)

Compute wavelength for specified photon energy.

Parameters: eV (float) – Photon energy [eV]. Wavelength [nm]. float
plask.phys.nm2eV(nm)

Compute photon energy for specified wavelength.

Parameters: nm (float) – Wavelength [eV]. Photon energy [nm]. float
plask.phys.wl(mat, lam, T=300.0)

Compute real length of optical wavelength in specified material.

This is utility function that computes the physical length of a single wavelength in specified material. Its main purpose is easier design of DBR stacks.

If you are using it with custom materials, make sure that it does provide nr() method.

Parameters: mat (material.Material or str) – Material to compute physical wavelength in. lam (float) – Free-space wavelength to scale for material mat [nm]. T (float) – Temperature at which material refractive index is retrieved. Real length of the one wavelength in the material [µm]. float