Ultrafast multivalley optical switching in germanium films controls transparency at multiple wavelengths using a single-color pulse laser

https://www.eurekalert.org/news-releases/1080525

"optical bleaching induces nonlinear effect temporarily altering material's properties... not based on microelectromechanics requiring electricity resulting in slow response... overcomes single-color optical nonlinearities' limitations... ultrafast optical switching in both Γ and L valleys, due to intravalley/ intervalley scattering... 240 meV split-off energy at L high symmetric point... Ge is a key material for advanced optical switching, with promising applications in high-speed data transmission and computing"