Semiconductor quantum well electron and hole waveguides

DETAILED DESCRIPTION FIG.
1 shows, in pictorial form, the energy level diagram and the structure of asymmetric, quantum well slab waveguide 100.
We will use the following notation in describing this embodiment of the present invention: (a) layer 200 will be referred to as substrate layer s, layer 201 will be referred to as film layer f, and layer 202 will be referred to as cover layer c; (b) the direction perpendicular to the surfaces of waveguide layers 200-202 denoted by arrow 100 will be referred to as x.
sub.
w ; (c) the electron potential energy at the bottom of the quantum well in layer 201, i.
e.
, film layer f, will be referred to as V.
sub.
f ; (d) the electron potential energy barrier heights associated with layer 200, i.
e.
, substrate layer s, and layer 202, i.
e.
, cover layer c, will be referred to as V.
sub.
s and V.
sub.
c, respectively; (e) layers 200-202 are comprised of materials from a material system of the type F.
sub.
1-x G.
sub.
x H, and, as a result, we will refer to the compositions of layers 200-202, i.
e.
, substrate layer s, film layer f, and cover layer c, as x.
sub.
s, x.
sub.
f, and x.
sub.
c, respectively; (f) the direction of guided mode propagation denoted by arrow 110 will be referred to as z.
sub.
w ; (g) the thickness of waveguide layer 201, i.
e.
, film layer f, will be referred to as d; (h) the angle of incidence of the two plane wave components that constitute an electron guided wave will be referred to as the zig-zag angle .
theta.
; (i) the magnitude of the electron wavevector in any of layers 200-202 is given by k.
sub.
=[2m.
sup.
*.
sub.
i (E-V.
sub.
i)].
sup.
1/2 /h, where i=s, f, c for substrate layer s, i.
e.
, layer 200, film layer f, i.
e.
, layer 201, and cover layer c, i.
e.
, layer 202, respectively, and where m.
sup.
*.
sub.
i is the electron effective mass, V.
sub.
i is the electron potential energy, and E is the total electron energy.
In the following description, because layers 200-202 are comprised of materials from the Ga.
sub.
1-x Al.
sub.
x As material system, the electron potential energies in layers 200-202 of waveguide 100, i