Hello to all. Nice forum. Really like it. I hopee you'll can help me.(adsbygoogle = window.adsbygoogle || []).push({});

The rate equaition in the case of reverse saturable absorber, with a long-lived strongly absorbing excited state (T0) which is rapidly populated from a ground state (S0), are given as:

[itex]\frac{dS_{0}}{dt} = - \sigma_{01} S_{0} \phi + k_{30}T_{0} [/itex]

[itex]\frac{dT_{0}}{dt} = \sigma_{01} S_{0} \phi - k_{30}T_{0} [/itex]

[itex]\frac{d \phi}{dz} = - \sigma_{01} S_{0} \phi - \sigma_{34} T_{0} \phi [/itex]

[itex]\phi[/itex] is the photon flux, [itex]\sigma_{ij} [/itex] - ij-transition cross-section.

Thу last equation describes the light absorption in the sample depth. To solve these equations numerically with RK-method it is necessary to reduce the last one to the form [itex]\frac{d \phi}{dt}[/itex].

In the literature i met the change of variable which led to [itex]\frac{1}{c}\frac{d \phi}{dt}[/itex]. Why is it correct? What is about refraction in the sample?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Reverse saturable absorption. Rate equations.

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**