Preface This thesis describes investigations on experimental studies involving spectroscopic examinations of yttrium aluminum garnet (YAG) with various impurity concentrations, and the laser performance of a limited number of similar materials. The thesis is divided into three chapters, the first of which provides various background information on YAG. Chapter II describes the equipment and procedures used in performing the spectroscopic studies and presents the results obtained. This...

Abstract The tungsten-p type silicon point contact diode was investigated as a video detector from 90 GHz to 474 THz. The diode responsivity was examined with respect to the applied pressure of the contact and the D. C. characteristics. An upper limit of approximately 2 THz is established for electromagnetic field detection, with thermoelectric effects appearing as the frequency is lessened. Typical responsivity values of 100v/w at 90 GHz, 2v/w at 890 GHz, 10⁻²v/w at...