University of Utah Research Foundation

Barnes Engineering Company

Fritz Luty

Werner Gellermann

James E Moore

Yihong Yang

George Csanak

B Michael Kale

A narrow-band filter for absorbing radiation at a wavelength in the range of 9.2 to 10.8 microns and for transmitting radiation in a surrounding 8 to 12 micron band having a high transmission ratio. The filter is comprised of a pure or mixed alkali-halide crystal having optical incidence and transmission surfaces and thiocyanate or borofluoride as an impurity.

Narrow-band optical absorption filter

Stable color centers capable of laser emission in the near infrared region of the optical spectrum are provided in alkali halide host crystals containing monovalent heavy metal cation impurities such as thallium, gallium, indium, silver and copper. The laser active color centers are formed by exposing the crystal to ionizing radiation followed by irradiation with light having a wavelength absorbed by the F centers. The resulting material is capable of stable, broadly tunable laser operation with high power output in the near infrared region. Oscillation on a single mode can be easily obtained.

Color centers for tunable lasers in the near infrared region

Vibrational emission from molecular defects in ionic crystals can be realized by dilute diatomic molecular defects such as, e.g., CN.sup.- molecules in alkali halide crystals. After association of F-centers to the CN.sup.- molecules, forming a new F-center/molecular defect pair, the emission can be pumped by optical F-center excitation through electronic-vibrational coupling. Using this coupling mechanism, laser action in the near infrared wavelength region is obtained between vibrational energy levels of the molecules while pumping the F-center/molecule defect in the visible wavelength range. The laser crystals are prepared by additively coloring a CN.sup.- doped alkali halide crystal and exposing the colored crystal to light having a wavelength capable of being absorbed by the electronic F-center/molecule defect transition.

Growing community of inventors

Salt Lake City, UT, United States of America

Fritz Luty