Hot electrons and curves of constant gain in long wavelength quantum well lasers.

In long wavelength quantum well lasers the effective electron temperature (T(e)) is often a strong function of the pump current and hence the T(e) correlates with the carrier concentration n in the active region. On the other hand, the material gain g in the active layer depends on both variables, g=g(n,T(e) ). We discuss a convenient way of analyzing this situation, based on considering the contours of constant gain g on the surface g(n,T(e) ).

[New potentials for scanning electron microscopy in the study of hair].

Presents data on differentiation by scanning electron microscopy of pigment eumelanin of human hair and of some animals' hair morphologically similar to human, as well as of hair core disks in closely related animals. The method was used in expert evaluations.