diffraction

A ‘collimated’ laser beam has a slight divergence (the beam expands) as it propagates through a material or a vacuum. This effect is called ‘diffraction’ and results from light passing through the output aperture of the laser. For a laser beam having 1/e radius R0 and wavelength λ0 propagating though a material having a linear refractive index n0, the ‘diffraction length (Ldf)’ or ‘Rayleigh Length’ is defined as

Ldf = π (R0)2 n0 / λ0

If the sample thickness is less than Ldf, or optically thin, then the divergence of the beam as it passes through the sample is small and can probably be ignored. If the sample thickness is greater than Ldf, or optically thick, then the divergence of the beam will be noticeable.









SimphoSOFT® can be purchased as a single program and can be also configured with Energy Transfer add-on ET add-on, Multi-Beam add-on Multi-beam add-on, Optimization add-on Optimization add-on, Z-scan add-on Z-scan add-on, and MPA Info+ add-on MPA Info+ add-on for an additional charge. Please, contact our sales staff for more information
  • e-mail
  • phone: +1 (973) 621-2340
You can request a remote evaluation of our software by filling out online form -- no questions asked to get it, no need to install it on your computer.