We describe how to spin-polarize ballistic electrons in a
two-dimensional semiconductor heterostructure with a field-effect gate
control of the spin-orbit interaction. In the suggested scheme (which
we term spin-optics), a beam of electrons splits in two spin-polarized
components propagating in
different directions. The phenomenon of the spin-dependent refraction
of the electrons is similar to the birefringence of light in crystal
We outline possible devices based on the spin-optics approach,
including spin filter and spin switch. We also discuss how the
phenomenon of the diffuse emission can help the realization of this
"Spin Polarization of Electrons by Nonmagnetic Heterostructures: The Basics of Spin Optics", Phys.Rev.Lett. 92, 086602 (2004).
"Diffuse emission in the presence of an inhomogeneous spin-orbit interaction for the purpose of spin filtration", Phys.Rev.B 71, 125114 (2005).