ABSTRACT
This chapter describes various elements and operating regimes of spin-lasers. It provides a description of spin-unpolarized lasers that can be readily generalized to spin-lasers, which are subsequently analyzed in both their steady-state and dynamical operations. The chapter discusses conventional lasers and spin-lasers depending on whether the pumping/injection introduce spin-unpolarized or spin-polarized carriers, respectively. Introducing spin-polarized carriers in semiconductor lasers offers an alternative path to realize spintronic applications, beyond the usually employed magnetoresistive effects. Through carrier recombination, the angular momentum of the spin-polarized carriers is transferred to photons, thus leading to the circularly polarized emitted light. There is also an alternative approach to reduce the lasing threshold using spin-polarized carriers generated by circularly polarized light or electrical spin injection. The modulation of spin polarization in lasers has motivated introducing the concept of spin interconnects while using the spin-polarized carriers can also enable coherent emission of sound.
