  Due to coherent population oscillation (CPO) effect, we theoretically examine
the generation and manipulation of Laguerre-Gaussian beams in terms of phase
and amplitude modulation respectively in semiconductor quantum dots (SQDs). The
results indicate that both phase modulation with low absorption of probe field
and amplitude modulation with high efficiency can be achieved. Thus the
practical way demonstrates that the SQDs system can function as effective
optically addressed spatial light modulator with which the transverse spatial
properties of probe fields can be artificially modulated.
