Download or read book Coherent Tunable Thz-FIR Radiation Sources written by and published by . This book was released on 1999 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: As described by the title the grant funds were used to support a project whose primary goal was the development of tunable coherent sources for the THz-FIR region of the spectrum. The THz or more generally the FIR extends from 0.3 x 10(exp 12) (0.3THz) to 30 x 10(exp 12) (30THz) or alternatively from a wavelength of 1 mm down to a wavelength of 10 gm. It is a range of the spectrum that has been a long standing challenge. Microwave technology which has been extraordinarily successful at wavelengths longer than 1 mm and classical and quantum optical techniques which are extremely effective in the visible, near and mid infrared regions of the spectrum encounter fundamental challenges when extended (respectively) to longer or shorter wavelengths. Continued interest in "opening up" and exploiting the FIR region of the spectrum is based on the scientific questions which in part demand an access to the THz-FIR spectral range. These extend from atmospheric and biophysics to plasma physics and radio astronomy. Important technological applications also exist. Among the examples would be radar modeling, characterization of the response of near millimeter wave (NMMW) systems and the potential for short range high resolution radar. The immediate scientific and engineering goals of the project supported by the equipment grant provide a source that is tunable, narrow band and provides sufficient power for spectroscopic investigations. In the longer term a compact conveniently packaged sources and potential and requirements needed to reach higher power operation are of interest. The grating couples the beam with the electromagnetic field provides distributed feedback which reacts back on the beam and in turn leads to bunching of the beam. The density bunches produce the coherent operation.