Possible Condensation Laser
{'Code': '07020000', 'Directorate': {'Abbreviation': 'ENG', 'LongName': 'Directorate For Engineering'}, 'Division': {'Abbreviation': 'CBET', 'LongName': 'Div Of Chem, Bioeng, Env, & Transp Sys'}}
{'SignBlockName': 'MILTON J LINEVSKY', 'PO_EMAI': None, 'PO_PHON': None}
1.  Summary of Proposed Research:  Experiments to be carried out will           consist in exposing various gas mixtures to a corona discharge in a             source chamber and then expanding the excited gas through a small               nozzle into vacuum as a supersonic jet.  Of particular interest are             species whose excited states radiate in the infrared such as CO and             CO2.  Their radiation from the jet will be analyzed by Fourier                  Transform Infrared Spectrometry as well as by total radiation                   detectors.  In some preliminary experiments the intensity of the                radiation showed as much as a fivefold increase when the initial                temperature and pressure of the source gas were such that condensation          would be expected during the free jet expansion.  The question thus             arises as to whether this observed "superradiance" was due to a                 population inversion caused by clustering of the ground state                   molecules which would shift their absorption wavelength so that they            could not absorb photons radiated by excited monomers.  The objective           of the research is to determine with what species and under what                conditions the superradiance can be made to occur, the nature of the            underlying mechanism, and whether that mechanism offers an effective            new approach to useful lasers in the infrared regime.                           2.  Novelty:  The sine qua non of laser operation is a population               inversion in which the number density of molecules in an upper                  excited state exceeds the number density in the lower state                     produced when the excited molecule radiates a photon.  Many kinds               of processes have been used to populate an upper state in a laser               system and/or to depopulate the corresponding lower state.  To                  our knowledge inversions have not previously been achieved by the               use of condensation to depopulate the lower state.  In principle                it should work and preliminary experiments with supersonic free                 jets indicate that it can occur in rapid adiabatic expansion of a               gas containing vibrationally excited species.                                   3.  Technological Impact:  Preliminary experiments have shown                   remarkable superradiance from free jets containing vibrationally                excited CO and CO2.  The tentative explanation is a population                  inversion due to clustering or condensation of molecules in the                 lower state.  If this conclusion is confirmed by the proposed                   research, the way would seem open for the development of new                    "condensation laser" systems.  Because this approach should be                  applicable to almost any gaseous species that is infrared-active,               there looms the prospect of a wide range of laser systems                       covering a large part of the infrared spectrum.  Relatively                     complex molecules should offer tunability.  Quantum efficiencies                should be high because the lower state must have little or no                   remaining internal energy in order to condense.
{'FirstName': 'John', 'LastName': 'Fenn', 'PI_MID_INIT': 'B', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'John B Fenn', 'EmailAddress': 'JFENN@SATURN.VCU.EDU', 'NSF_ID': '000352037', 'StartDate': '09/01/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Yale University', 'CityName': 'NEW HAVEN', 'ZipCode': '065113572', 'PhoneNumber': '2037854689', 'StreetAddress': '150 MUNSON ST', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Connecticut', 'StateCode': 'CT', 'CONGRESSDISTRICT': '03', 'CONGRESS_DISTRICT_ORG': 'CT03', 'ORG_UEI_NUM': 'FL6GV84CKN57', 'ORG_LGL_BUS_NAME': 'YALE UNIV', 'ORG_PRNT_UEI_NUM': 'FL6GV84CKN57'}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '1407', 'Text': 'CFS-Combustion & Fire Systems'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8819659.xml'}