美国无线电公司研制成一种砷化镓场效应晶体管,可用作微波开关。它可由1.5微米的红外光(通常可在普通的闪光束中发现)控制。器件制成一个薄片且插入波导中,其表面电阻率可用照射在其上的吸收至反射的方法来改变。这种器件与普通的场效应晶体管不同,它包含一个在 N 层下掺铬的半绝缘衬底。假如N 层耗尽,器件成为一个绝缘体,其沟道或衬底都不导通。在其他场效应晶体管中,耗尽后 American radio company developed a gallium arsenide field effect transistor, can be used as a microwave switch. It can be controlled by 1.5 micron infrared light (usually found in normal flash beams). The device is made into a sheet and inserted into a waveguide whose surface resistivity can be varied by the method of absorption to reflection that impinges on it. Unlike ordinary field-effect transistors, this device includes a semi-insulating substrate that is chromium-doped under N-layer. If the N-layer is depleted, the device becomes an insulator with no channel or substrate on it. In other field-effect transistors, after depletion