The quantization of a completely chaotic system-the baker's transforma
tion-is investigated using the fact that the relationship between clas
sical and quantum mechanics is directly analogous to the one between r
ay and wave optics. A class of optical systems is constructed for whic
h the ray dynamics is governed by the baker map. Applying wave-optical
methods to these physical systems then gives, in the standard way, th
eir corresponding quantum dynamics. The result is that in certain case
s the quantum propagator is identical to that found previously using a
n ad hoc mathematical quantization procedure. However, this is not alw
ays so-for other systems with the same classical (ray) limit there are
important differences. In particular, the propagator need not be bloc
k-diagonal in its q-p' representation, as had previously been assumed,
although it always tends to this basic form in the semiclassical limi
t.