We report on optically induced transport phenomena in freely suspended channels containing a two-dimensional electron gas (2DEG). The submicron devices are fabricated in AlGaAs/GaAs heterostructures by etching techniques. The photoresponse of the dev
ices can be understood in terms of the combination of photogating and a photodoping effect. The hereby enhanced electronic conductance exhibits a time constant in the range of one to ten milliseconds.
