The attenuator-magnifier schematic for the electronic magnification of the specimen is shown in figure E5. Figure E6 is the schematic for the reflected-light amplifier with the germanium photodetector. This circuit obtains its operating power from the mixer. The schematic for the dc to 100 kHz laser modulator is shown in figure E7. A novel approach to high voltage control is used in the modulator. The screen of a tube designed for horizontal output service in television sets is driven with direct-coupled circuitry to yield a reliable high voltage switch. The grid and cathode are connected together in this scheme. As a result, the common failure mode of grid to cathode short, which is the real voltage limiting factor in such devices, is eliminated, and the voltages commonly used in gas lasers can easily be switched. Figure E8 is the schematic for the high impedance probe which can be used in applications where device loading is important. The probe obtains its operating power from the mixer. In the specifications section of this report the resolution figures are specified as percentages. Figure F1 helps explain the meaning of these numbers in terms of measurable quantities. Figure Fla shows the detector output as a function of laser spot position on a resolution test target if the resolution were perfect. The test target contains both widely spaced bars which serve as a reference, and closely spaced bars with a separation d. The distance d is the test pattern line spacing to which the resolution is referenced in the specifications. Figure F1b shows a typical output which is obtained from the detector due to the finite resolution of the system. The resolution given in the specifications is defined as |