Two photon absorption in silicon

[Barth]

How does work the two-photon absorption ?

Does it exist a Beer-Lambert law for this kind of process?
If yes, does someone know where i could find the order of magnitude of two-photons absorption coefficient for silicon at 1500 nm ?

Barth

[Claude Bile]

Nonlinear absorption of this sort occurs for very high laser intensities, typically, for the infrared at least, one needs to blast silica with at least a nanojoule femtosecond pulse to observe these effects.

The two-photon absorption in silica at the kind of intensities you are likely to find from a 1500nm source, the TPA would be negligibly small.

Claude.

[Barth]

The source we are using is the "classic" Tsunami-Opal femtosecond line. We then have at 1500nm a relatively high peak intensity, that's why i would like to evaluate two-photon absorptions.

[Gokul43201]

2 photon absorption coeff in Si : 0.45 cm/GW at 1540 nm

Tsang et al, App Phys Lett, 80, 416 (2001)

[Barth]

Thanks a lot

[Claude Bile]

The source we are using is the "classic" Tsunami-Opal femtosecond line. We then have at 1500nm a relatively high peak intensity, that's why i would like to evaluate two-photon absorptions.

Fair enough :blushing: . I never considered 1500 nm to be within your typical window of femtosecond pulse generation, but it appears I was wrong.

Claude.