Diode pumped Nd:YAG laser development

A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work

Hot-electron thermocouple and the diffusion thermopower of two-dimensional electrons in GaAs

A simple hot-electron thermocouple is realized in a two-dimensional electron system (2DES) and used to measure the diffusion thermopower of the 2DES at zero magnetic field. This hot-electron technique, which requires no micron-scale patterning of the 2DES, is much less sensitive than conventional methods to phonon-drag effects. Our thermopower results are in good agreement with the Mott formula for diffusion thermopower for temperatures up to T~2 K

Multibeam optical apparatus and method for tracking control for an optical disk having a set of tracks

A multitrack optical disk has two or more circular or spiral tracks, which are recorded or played back in simultaneous sets for high data rates. Tracking is accomplished by sets of first and second tracking pads, which lie partially on and partially off the track paths. The amount of inter-track space required to accommodate the track pads is reduced by placing the overlap of the tracking pads in the same inter-track space, and by tracking any additional simultaneous tracks in excess of two by mechanical coupling with the first two

Solar-pumped laser Final report

Solar pumped modulated laser to generate coherent radiation at optical wavelengths for long range, real time television data transmissio

Cerita Rakyat Timun Emas: Gambaran Runtuhnya Ideologi Patriarkal

Patriarchal ideology puts women as subordinate and feel inferior in various facets of life. thought it was getting counter-discourse presented by the text tale of Timun Emas. In the text, described the loss of the role of men as the highest authority in live. The role of men is represented by four figures; the husband, Ki Butakala, Ki Pertapa, and the Prince. They have superiority , but then lost control of the two rival of women; Nyi Niken and Timun Emas. In the text implied that Nyi Niken and Timun Emas does not need a male figure in their lives. In accordance with the above description, analysis tale of Timun Emas uses feminist approach to look at the differences in the function and role of the human (between of man and woman). So it can be concluded that the tale of Timun Emas events that indicate a loss of patriarchal ideolog

Ultrahigh energy neutrinos, small x and unitarity

The ultrahigh energy cross section for neutrino interactions with nucleons is reviewed, and unitarity constraints are discussed. We argue that existing QCD extrapolations are self-consistent, and do not imply a breakdown of the perturbative expansion in the weak coupling.Comment: 5 pages, 2 figures, RevTeX4, contribution to Snowmass 200