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公开(公告)号：CA1136893A
公开(公告)日：1982-12-07
申请号：CA355797
申请日：1980-07-09
Applicant: IBM
Inventor： BETHUNE DONALD S , LANKARD JOHN R , LOY MICHAEL M T , SOROKIN PETER P
Abstract: TIME-RESOLVED INFRARED SPECTRAL PHOTOGRAPHY An intense broadband continuum light pulse of uniform spectral intensity and short time duration is generated, then downconverted in frequency to a region of interest, preferably in the infrared region, by applying it as a pump pulse to a molecular or atomic vapor so as to induce stimulated Raman scattering. The resulting uniform spectral intensity distribution Raman Stokes pulse is then used to probe a sample. The sample converts the distribution of the probe pulse into a nonuniform spectral intensity distribution which contains the absorption spectrum of the sample. This spectrum pulse has the same spectral bandwidth and time duration as the Raman Stokes pulse and is finally upconverted in frequency to a region where the spectrum pulse can be conveniently recorded. This is done with a four-wave Raman mixing process in an alkali metal vapor. The vapor is simultaneously pumped with the spectrum pulse and with a second pumping light pulse (or beam) having a frequency in the vicinity of a suitable resonance line of the vapor so as to induce SERS. In the alkali metal vapor, the resulting Raman Stokes pulse and spectrum pulse beat together with the second pumping light pulse to produce an upconverted pulse at a higher frequency band, which surprisingly also tends to have the same spectral bandwidth, intensity distribution (spectrum) and time duration as the spectrum pulse. The upconverted pulse is then recorded either photographically or photoelectrically with conventional spectrographic apparatus. YO9-79-063
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公开(公告)号：CA1128180A
公开(公告)日：1982-07-20
申请号：CA335809
申请日：1979-09-17
Applicant: IBM
Inventor： LOY MICHAEL M T , SOROKIN PETER P
Abstract: TUNABLE 16 MICRON COHERENT SOURCE INCLUDING PARAHYDROGEN RAMAN TRANSITION AND METHOD A coherent tunable narrow band IR source in the vicinity of 16 um is achieved by four-wave parametric mixing in parahydrogen. A pair of colinear laser beams, one from a narrow band CO2 laser, and a second from a multiline laser with output of wave number significantly below 14,400 cm.-1, is focused in a parahydrogen containing cell. The multi-line laser beam drives a Raman process in the cell. The narrow band CO2 input beam mixes with this driver beam and the Stokes wave resulting from the Raman process to produce a 16 um output beam. Tuning of the CO2 laser allows tuning of the 16 um radiation emitted by the parahydrogen cell. YO978-025
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