The construction and performance of a Fourier transform spectrometer designed for the far infrared spectroscopy is described. The spectrometer has a combined optics of Michelson's and Martin -Puplett's. Some cooled high sensitive semiconducting detectors are used. Gaseous absorption spectra and the optical constants of dielectrics including some new materials have been measured and the results are presented. Resolution of 0.03 cm-1 and accuracy of wavenumber within ±0.001cm-1 are obtained.
We developed a flexible infrared optical fiber to direct a CO2 laser beam with the capability of incision and vaporization into the interior of a human body to destroy diseased organs. The features of our optical fiber are the following: (1) high flexibility with radius less than 20mm and high endurance capability against repeated flexing of more than 5000 times; (2) high power transmission output capability of up to 65 W. To achieve this high flexibility, the diameter was decreased and the materials strength was increased. We developed a new hot extrusion method whose load avoids deformation of the fiber due to the small radius, and got a straight fiber with 0.3mm in diameter. With the high pressure extrusion method, we got a yield strength four times higher than that of the AgCl0.5Br0.5 crystalline.