(NASA-CR-78855: SID-65-1466) CFSTI: HC $7.00/MF $1.75 CSCL 20E The system implementation study of the laser space communications system is reported. A description and component performance analysis is given for each experiment, including experiment configuration and the required equipment list. A system synthesis is presented. with experiments grouped into a basic application-oriented program, a minimum theory-oriented program, and the maximum program. Site support considerations are discussed, including the selection of suitable sites, and information on available weather facilities and statistical weather data. Discussions are presented on ground, airborne, balloon, and satellite links. It was concluded that: (1) System components and wellinstrumented accessible sites for stationary ground-based links are available. (2) Aircraft and balloon platforms with required support are also available. (3) A thorough field testing with ground-based and airborne platforms is necessary. N.E.N. (NASA-CR-78856; SID-65-1467) CFSTI: HC $3.00/MF $0.75 CSCL 20E The program specification of the laser space communications system study is summarized. The approach to a program of field experimentation to determine atmospheric effects on laser propagation is outlined. The theoretical versus experimental aspects were considered. emphasizing space and non-space tests, and performance characteristics of experimental equipment. Anticipated problem areas are identified as (1) the unknown reliability of laboratory equipment in a field environment and (2) the utilization of small specialized test teams with a wide geographic spread. The program sequence recommendations, schedule, and implementation cost estimates are included. N66-39448*# N.E.N. North American Aviation, Inc., Downey, Calif. Space and Information Systems Div. LASER SPACE COMMUNICATIONS STUDY (LACE) Final Summary Report N66-39473# Aerospace Medical Div. Aerospace Medical A STUDY OF LIGHT MODULATION AND SCANNING Various techniques for modulation and scanning of coherent light are analyzed for application to the generation of high resolution high contrast displays for simulation. A number of possible techniques are discussed in the main body of the report. The individual discussions include a brief description of the principles of operation together with capabilities relative to bandwidth, contrast ratio, deflection angle, alignment, sensitivity. ease of fabrication, and handling. This is based somewhat upon voltage and power requirements over range of operation. Author (TAB) N66-39487# Stanford Univ., Calif. Microwave Lab. OF SEVERAL OPTICAL NONLINEARITIES USING FOCUSED GAUSSIAN LASER BEAMS John E. Bjorkholm Jan. 1966 133 p refs (Contract AF 49(638)-1525) (ML-1405; AFOSR-66-0490; AD-637500) CFSTI: HC $4.00/MF $1.00 The twofold purpose of this study was: (1) to analyze optical second-harmonic generation (SHG) in the focus of the lowest order transverse mode of a cw gas laser beam; (2) to utilize the power enhancement available from focusing to measure smaller nonlinearities on a cw basis than previously had been done. The results of the analysis give the dependence of SHG in indexmatching crystals upon the crystal length, the crystal doublerefraction angle, and the laser beam focal spot size wo. The dependence of SHG upon wo was measured using varying degrees of focusing. The absolute power levels were checked by measuring the absolute value of the nonlinearity in ADP. The excellent agreement between analysis and experiment means that focused beams can be used to make accurate measurements of crystal nonlinearities. The second section of this study describes measurements of several optical nonlinearities in calcite made under conditions of optimum focusing using cw gas lasers. Since calcite has a center of inversion, the nonlinearities measured are of higher order than normal dipolar SHG; the resulting effects are much weaker, requiring the use of focused beams to detect them. Measurements were made of quadrupole-type SHG, electric-field-induced SHG, and the quadratic electro-optic effect. Author (TAB) N66-39733# Air Force Cambridge Research Labs., Bedford, E. J. Post May 1966 51 p refs Its Phys. Sci. Res. Papers (AFCRL-66-311; AD-637717) CFSTI: HC $3.00/MF $0.50 A revived interest in the Sagnac effect, because of its navigational potentialities has recently resulted from the development of the self-oscillating laser version of the original Sagnac interferometer. Where the Sagnac interferometer or ring laser is an example of an electromagnetic sensor of absolute rotation, it was believed that some historical and theoretical background information might be useful in exploring and further evaluating the possibilities of electromagnetic sensing of absolute rotation. A critical literature study of the many experimental ramifications and the older kinematical theory of the effect is presented. This geometric optical theory is then complemented and compared with more recent work that is based on a physical optical analysis using a complete electromagnetic description of the phenomenon Author (TAB) A report is given of work dealing with theoretical and experimental investigation of the properties of ferroelectric materials leading to the development of materials with the special properties necessary for the operation of a Ligant Field Maser in the millimeter range. Measurement of ligand fields near ground state crossovers by optical and microwave spectroscopy are discussed as well as magnetometer methods. Means by which Ligand Field Variation may be accomplished are considered, with associated experimental techniques. Experience in the preparation of suitable materials and growth of single crystals are presented, and various possibilities analyzed. (Author) TAB In a study on the effects of space radiation on lasers, a discussion is given of the mechanisms by which these effects can occur, and of a suitable choice of parameters to be measured. These include active tests; measurements of coherence and of near and far field patterns; passive tests; optical transmission measurements; and scattering of transmitted gas laser light. Methods of measuring these parameters were developed and applied to optically pumped lasers such as ruby, CaWO4 Nd, YAG: Nd and Glass: Nd, and GaAs diode injection lasers, before and after irradiation with 32 Mev protons, 30 Mev electrons, and reactor Y rays. For GaAs diodes, irradiation does not change the current voltage curve, but degrades the optical output and changes the output wavelength spectrum. Coherence and far-field patterns are changed for all lasers if the input power is increased after irradiation to keep output power constant, and heating seems to be a more important cause of these changes than any direct effects of irradiation. Author N66-39966 # Melpar, Inc., Falls Church, Va. Electronics Research Lab. A STUDY OF LASER WAVE SCATTERING DUE TO REFRACTIVE INDEX PERTURBATIONS IN THE PROPAGATING MEDIUM Final Report, 5 Oct. 1965-15 Aug. 1966 S. B. Sample and S. J. Campanella Aug. 1966 97 prefs (Contract NAS9-5315) (NASA-CR-65553) CFSTI: HC $2.50/MF $0.75 CSCL 20F The purpose of this contract was to expand the GT-7 laser communicator experiment into a scientific study of laser wave scattering due to refractive index perturbations in the atmosphere. This report contains a complete description of the two data recording and processing systems that were constructed on the contract. It also describes the activities of the personnel who were stationed at the White Sands and Ascension Island Laser Communicator Sites during the flight of GT-7. An analysis of the data obtained during static laser wave propagation experiments at the WSMR site is included. Finally, the report presents recommendations for future space-to-earth and ground-based laser wave propagation experiments that seem necessary in order to further clarify the nature of optical propagation over great distances in the atmosphere. Autnor N66-39992*# North American Aviation, Inc., Downey, Calif Space and Information Systems Div. SPECIFICATION OF ATMOSPHERIC LASER PROPAGATION EXPERIMENTS, VOLUME II 15 Sep. 1965 refs (Contract NASW-977) (NASA-CR-79094; SID-65-1275) CFSTI: HC $5.00/MF $1.00 CSCL 20E Specifications are presented for a comprehensive experimental program to determine atmospheric effects on laser propagation. with particular emphasis on effects related to optical space-ground communication. The interrelationships between the optical effect. experimental variables, and individual variables are examined in a discussion on measurement approach. Also included are some basic interpretations of beam fluctuations in a turbulent atmosphere. a glossary of related terms and proposed modifications in the approach to the meterological experiments. Experimental procedures are outlined, and error and measurement analyses are prescribed. Error sources described are the result of considerations such as beam splitters, piezoelectric crystals, entrance aperture, signal to noise and gain, background, measurement time and number of measurements. mechanical vibration, tracking. circuitry S.P. maladjustments, modulators, and spot size. LASER CAVITIES. PART I: RESEARCH ON OPEN RESONATORS. PART II: BEHAVIOR OF THE OUTPUT FROM A MANY ELEMENT LASER Annual Summary Report, 1 Apr. 1965-30 Mar. 1966 P. F. Checcacci, A. M. Scheggi, R. Pratesi, and L. Ronchi 30 Apr. 1966 68 p refs (Contract AF 61(052)-871) (ASR-1; AFCRL-66-638; AD-638193) CFSTI: HC $3.00/MF $0.75 A summary of the researches completed during the last year is given along with detailed descriptions of the latest results. Investigation carried out on microwave models of laser resonators and study of new types of open resonators are reported in Part I. Part II is concerned with the study of the time behavior of the light emitted from a many element laser (MEL) Author (TAB) N67-10437# Library of Congress. Washington, D. C. Aerospace Technology Div. BLEACHING MECHANISM OF ORGANIC PHOTOTROPIC SUBSTANCES USED IN RUBY LASERS AS SWITCHES Surveys of Foreign Scientific and Technical Literature Frances Mc Dowell 26 Sep 1966 9 p refs Transl. into ENGLISH from Zh. Prik Spektroskopii (USSR), v. 4, no. 5, 1966 p 410-414 (ATD-66-119) The bleaching process of organic phototropic switches under the effect of ruby laser emission is examined. The effect of the atomic constants of solutions on the bleaching process is evaluated. Author N67-10788*# National Aeronautics and Space Administration. E. Hirschmann Washington, NASA, Nov. 1966 17 p refs This report discusses the performance of KD2 P. GaAs and HMTA light modulators. The KD2P crystals have given excellent results in modulating a laser beam. Alignment of the crystal with relation to the light beam is very critical. GaAs appears at this time to be the best electro-optic crystal material for a light modulator in the infrared region between 0.9 and 16 microns Strain-free GaAs can be grown with resistivities exceeding 106 ohm-cm At this time, the use of HMTA as a light modulator material does not appear promising. Author N67-10948# Materials Research Corp. Orangeburg, N. Y. INVESTIGATION OF ELECTRON BEAM PROCESSING OF ALUMINUM OXIDE AND RELATED MATERIALS W Class, Harvey R Nesor, and O T. Murray 15 Jun. 1966 50 prefs (Contract AF 19(628)-4089) CFSTI HC $2.00/MF $0.50 Float-zone crystal growth techniques were applied to the preparation of refractory nonconducting crystals currently of interest to the laser technology. In these studies, sapphire and ruby served as test materials to evaluate the advantages and limitations of the float-zone methods. Two distinct procedures were employed to produce the molten zones in non-conducting materials. An electron beam technique utilizing a self-accelerated electron gun of annular geometry was the first process examined during the program. A second technique the production of a floating zone by the use of a hollow cathode electrical discharge was also developed. Both methods yielded single crystals of relatively high perfection as measured by the density of dislocations appearing in the grown crystals. Further evaluation is necessary to fully determine if the optical perfection of these crystals is commensurate with the stringent requirements demanded of a good laser crystal. TAB N67-10950# Minnesota Univ., Minneapolis. Dept. of Electrical INVESTIGATIONS OF GIANT PULSING METHODS IN 翼 RUBY LASERS David Roy Dean and R. J. Collins Aug 1966 81 p refs (Contract Nonr-710(61)) (TR-4; AD-637825) CFSTI: HC $3.00/MF $0 75 The findings from investigations into producing giant optical radiation pulses from ruby lasers by control of static cavity geometry are discussed, the experimental evidence produced by the investigations is presented, and a phenomenological model is proposed Optimum ranges for the cavity parameters of length, mirror reflectivity, and misalignment are established. For the new giant pulsing method the output pulses produced by the static cavity geometry control method have been found to be similar to the output pulses obtained by the present conventional giant pulsing methods Author (TAB) N67-10968# New York Eye and Ear Infirmary, N. Y. INVESTIGATION OF THE EFFECTS OF RUBY LASER RADIATION ON OCULAR TISSUE Jerry H. Jacobson, Harold W. Najac, and Bossom Cooper Phila.. Pa., Frankford Arsenal, Jun. 1966 34 pref (Contract DA-36-038-AMC-685(A)) (FA-R-1815; AD-638917) CFSTI: HC $2.00/MF $0.50 A series of laboratory and field experiments on rabbits were conducted by the New York Eye and Ear Infirmary in order to establish tentative safe operational distances and conditions for use of the Frankford Arsenal XM23 laser rangefinder. The measured far field corneal threshold dose for rabbits was tentatively determined to be 5x10 to the minus 7th power joule/sq. cm. From this a possible human corneal threshold was calculated as 0.00000145 joule/sq. cm. Based on this value, tentative safe operational distances were calculated as being 6460 meters for night (8 mm pupil). 1615 meters for twilight (4 mm pupil), and 914 meters for daylight (3 mm pupil). Author (TAB) N67-10978# Air Force Systems Command, Wright-Patterson AFB, Ohio. Foreign Technology Div. TEMPERATURE DEPENDENCE OF FREQUENCY AND EMISSION WIDTH OF THE R1 LINE OF RUBY M. Ye Movsesyan and Yu. S. Chilingaryan 25 Apr. 1966 8 p refs Transl into ENGLISH from Akad. Nauk Armyansk SSR (Erevan), v. 39, no. 4, 1964 p 217-219 (FTD-TT-65-2006; TT-66-62240; AD-638901) The conditions for induced radiation are most easily fulfilled for the maximum line of luminescence, and consequently there should be complete coincidence of the dependences on the temperature of the displacement on the maxima of the line of luminescence and the induced emission. In this work there was investigated the shift of the maximum of the line of fluorescence of Ruby R1 as depends on the temperature, and this change was compared with the temperature change of the maximum of induced emission. TAB Dept. of N67-11104# Johns Hopkins Univ., Baltimore. Md. Physics. LASER RAMAN SCATTERING STUDIES OF CRYSTALS Annual Technical Report, 15 Jun. 1965-15 Jun. 1966 Herman Z. Cummins Jun. 1966 16 p refs (Contract Nonr-4010(06) ARPA Order-306-63) (AD-637256) CFSTI: HC $2.00/MF $0.50 Laser excited raman scattering has been explored as a technique for studying crystals containing impurities, particularly the rare-earth doped crystals widely used as laser materials. Spectra obtained with both and A(+)4880 A laser and a He-Ne 6328 A laser are given for CaF2 and CaWO4 crystals, both pure and doped with various rare earths. To date, the doped crystals studied have either produced strong fluorescence or else given spectra which are indistinguishable from those of the pure crystals. Modification of the instrumentation is discussed which is currently in progress. With the improved apparatus, further efforts are planned to look for electronic raman structure of the rare earth ions as well as modification of the vibrational raman structure due to perturbation of the lattice by the impurities. Author (TAB) N67-11161# Air Force Systems Command, Wright-Patterson AFB, Ohio Foreign Technology Div. INTERFERENCE MEASUREMENT OF HOMOGENEITY OF RUBY RESONATOR FOR THE LASER V. Bocer and V. Kment 31 Aug. 1966 13 p refs Transl. into ENGLISH from Jemna Mechanika a Optika (Czechoslovakia), no. 1, 1965 p 5-6 (FTD-TT-66-44; TT-66-62249; AD-638978) CFSTI: HC $1.00/MF $0.50 N67-11314# Air Force Systems Command, Wright-Patterson AFB, Ohio. Foreign Technology Div. AMPLIFICATION OF COHERENT RADIATION, USING THE EFFECT OF INDUCED RAMAN SCATTERING B. A. Akanayev, S. A. Akhamanov, and R. V. Khokhlov In its J. of Exptl. and Theoret. Phys. 1 Apr. 1966 p 1-5 refs (See N67-11313 02-16) CFSTI: HC $1.00/MF $0.50 A combination Raman generator is described which is based on the phenomenon of induced Raman scattering for the generation and amplification of the Stokes wave. Excitation of the proposed generator is accomplished using a ruby laser with Q-modulation. The beam of light from the ruby laser source is divided into two beams one of which passes along the benzenes irradiated by pumping, the other along an air filled vessel. Amplification is determined by comparing the ratio of the intensities of Stokes and Rayleigh components of each beam. Registration of amplification is produced on photographic plates. Preliminary experiments showed that by using the phenomenon of induced Raman scattering it is S.C.W. possible to construct a receiver of coherent radiation. N67-11315# Air Force Systems Command, Wright-Patterson AFB, Ohio. Foreign Technology Div. SPECTRAL CHARACTERISTICS OF A GAS LASER WITH A TRAVELING WAVE S. N. Bagayev, V. S. Kuznetsov, Yu. V. Troitskiy, and B. I. Troshin In its J. of Exptl. and Theoret. Phys. 1 Apr. 1966 p 7-10 ref (See N67-11313 02-16) CFSTI: HC $1.00/MF $0.50 The effects of decoupling of longitudinal modes on multimodality of a gas laser in a resonator with a traveling wave propagating in one direction were studied. A gas laser on the wavelength = 6328Å with an annular resonator was prepared in which clockwise (A) and counter-clockwise (B) traveling waves were generated. The resonator was formed by three mirrors, two of which had a transmission of 0.2% and 3.4%, respectively. The discharge tube was filled with a mixture of neon and helium in a ratio of 1:5 with a total pressure of 0.5 mm Hg. To produce a traveling wave with one direction, an additional mirror was used which reflected part of the energy of wave B to A. As a result. during generation the intensity of wave A was five to seven times greater than that of wave B. Interferograms showed that the number of modes in this system oscillated from one to two. Results indicated that the generated modes did not travel over the entire spectral lines but were connected with a certain section of them. and that the power of generation did not change with time. It is concluded that elimination of spatial heterogeneity of the field in a laser resonator permits strengthening of the bond between types of oscillation (even in case of non-uniformly widened lines) and makes it possible to obtain adequate power generation with one to two longitudinal modes. S.C.W. N67-11380*# National Aeronautics and Space Administration. AN INTERFEROMETRIC RANGING SYSTEM The need for an accurate linear measuring system in the range of one hundred meters has resulted in the investigation of potential laser applicability. An interferometric type ranging system which utilizes a continuous-wave laser is analyzed. Theoretical analysis shows that one can utilize the difference frequency between adjacent TEM longitudinal modes of a cw laser to make accurate distance measurements. Equations are developed to establish mathematically the relation between phase information, which results from the photo-mixing of two monochromatic light beams, and the path lengths of these two signals. The validity of this idea is verified experimentally. Measurements which were accurate to a half millimeter were obtained using this ranging system. The accuracy of the system is limited by the system's noise level and by the laser stability. Author N67-11738*# Case Inst. of Tech., Cleveland, Ohio. (NASA-CR-79511; A-29) CFSTI: HC $4.00/MF $0.75 CSCL 20E Discussed is the construction of an optical heterodyne system for measuring the electron density of a plasma. Initially the scheme is established theoretically, followed by a detailed account of the construction of the helium-neon gaseous lasers. Design parameters are established to determine the most efficient means of operation. It is found that the laser can operate at gas pressures and input currents from 1.6 mm to greater than 10 mm Hg pressure and 5 ma to greater than 60 ma respectively, with optimum operation Occurring at 3.8 mm Hg pressure at a current of 30 ma. The heterodyning of two laser beams is then considered; the stability of the resultant beat frequency is found to be seriously impaired by such environmental factors as building vibration and very small temperature fluctuations. The minimum frequency drift encountered in the experiment was approximately 50 kc/s in a 1 sec period and is comparable to the frequency shift obtained with an electron density of 1012 electrons/cc. Recommendations are then made which should either mitigate or eliminate the causes of frequency drift. Author N67-11969# Joint Publications Research Service. Washington, D. C. FEATURES OF CZECHOSLOVAK-PRODUCED GAS LASERS Frantisek Petru 12 p 27 Sep. 1966 Transl. into ENGLISH from Sdelovaci Technika (Prague), v. 1966, no. 6. Jun. 1966 p 208-209 (GUO-2177) CFSTI: $1.00 Technical aspects of gas lasers, including basic resonator setup, beam radius and polarization, and resonator adjustment, are presented. The use of these gas lasers is advised in cases where the emphasis is on monochromaticity and coherence, directionality. high intensity, perfect polarization, and continuous operation of S.P. discharge radiation. N67-12260*# Ohio State Univ. Research Foundation, Columbus. Dept. of Electrical Engineering. A PRELIMINARY INVESTIGATION OF LASER ACTION ASSISTED BY OXIDIZED HYDROCARBONS Benjamin Franklin Jacoby 7 Oct. 1966 12 p Its Rept.-1093-32 (Grant NSG-74-60) (NASA-CR-80090) CFSTI: HC $1.00/MF $0.50 CSCL 20E This report describes the apparatus constructed to investigate the possibility of new laser line in the infrared and far infrared regions and some preliminary results are presented of a study where CO2 and CO were generated by a chemical reaction within the discharge tube and made to laser. Author N67-12294# Pacific Missile Range, Point Mugu, Calif. DESCRIPTION AND APPLICATION OF LASER RADAR AT PACIFIC MISSILE RANGE J. L. Karney, J. E. Masterson, and W. E. Hoehne 17 Aug. 1966 22 p ref (PMR-TM-66-6; AD-638754) CFSTI: HC $1.00/MF $0.50 The prototype device, called the Mark III Lidar (light detection and ranging) is presently undergoing operational evaluation. A preliminary description of the data and results obtained are given. The lidar is a new and unique tool which promises to provide meteorologists and atmospheric physicists a means to accomplish tasks not possible using present equipment. The Lidar may someday assist the meteorologist in making short-range forecasts by providing slant-range visibility data and quantitative measurements of stratus density and fog thickness. The Lidar is capable of determining precise ranges to clouds (together with their bases and tops), measuring the height of temperature inversions, and detecting atmospheric phenomena in apparently clear atmospheres. At the present time, the Lidar data are used in conjunction with observations from other sources to supplement and improve existing weather information. With relatively minor modifications, the Lidar could significantly augment the present methods of gathering atmospheric data. Author (TAB) N67-12314*# Post Office Engineering Dept., London (England). THE HELIUM SYSTEM OF THE MASER INSTALLATION AT THE GOONHILLY SATELLITE-COMMUNICATION EARTH STATION H. N. Daglish and M. R. Child In NASA Goddard Space Flight Center Telstar I, Vol. 4 Dec. 1965 p 2183-2193 Submitted for Publication (See N67-12301 03-07) CFSTI: HC $7.48/MF $2.00 A traveling-wave solid-state maser amplifier, immersed in liquid helium for very low temperature operation, is used to provide the first stage of amplification in the receiving system of a communication-satellite earth station. A large vacuum pump is required to cause the helium to boil at reduced pressure and thus attain a temperature lower than 2°K to insure the operation of the ruby-crystalline alumina amplifier. The complete helium control equipment associated with the maser operation consists of a vacuum line along and down the aerial structure to the vacuum pump, equipment for controlling the flow of helium gas from the vacuum pump, and a helium storage container for return to the liquefaction plant. G.G. N67-12533# General Telephone and Electronics Labs., Inc., CHELATE LASERS Final Report, 1 Apr. 1963-31 Mar. 1966 The physical properties and operating characteristics of chelate laser systems are defined. The limitations of chelate solutions in such systems are described in terms of the chemical behavior of the component materials, and the chemical and spectroscopic properties of the chelates themselves are elucidated. Approaches for overcoming the intense absorption which limits the performance of chelate lasers are proposed. The document is comprised largely of reprints from the following sources: J. Chem. Physics V40 P2547-2553, P2553-2558 1964; J. Chem. Physics V42 P1081-1096 1965; J. Chem. Physics V41 P1214–1224 1964; J. Chem. Physics V41 P279-280 1964; Applied Physics Letters V2 P159-161 1963; Nature V202 P580-581 1964; J. Chem. Physics V41 P3998-4000 1964; Applied Physics Letters V5 P173-174 1964; Applied Optics Suppl. 2 of Chemical Lasers P205-213 1965. TAB 1. LASER MATERIALS RESEARCH H. W. Gandy, R. J. Ginther, and J. F. Weller p 1-13 refs (See N67-12646 03-26) 2. LASER MATERIALS EVALUATION PROGRAM W. H. Vaughan p 14 (See N67-12647 03-26) 3. MAGNETIC Q-SPOILING OF COOLED RUBY J. N. Bradford, J. W. Tucker, and R. C. Eckardt p 15-18 ref (See N67-12648 03-16) 4. GAS LASER RESEARCH A. W. Ali (Catholic Univ. of Am.), J. D. Shipman, A. C. Kolb, and A. D. Anderson refs (See N67-1264903-16) 5. BEAM SELF-FOCUSING IN LIQUIDS p 25 refs (See N67-12650 03-16) p 19-24 E. A. Mclean 6. HIGH-POWER LASER DEVELOPMENT J. M. Mc Mahon and B. G. Bricks P 26-29 refs (See N67-12651 03-16) 7. FLASHLAMP SPECTROSCOPY F. D. Harrington p 30-38 ref (See N67-12652 03-23) N67-12646# Naval Research Lab., Washington, D. C. H. W. Gandy, R. J. Ginther, and J. F. Weller In its NRL Progr. in High-Power Laser Res. 10 Jun. 1966 p 1-13 refs (See N67-12645 03-16) CFSTI: HC $2.00/MF $0.50 The main effort in laser materials research was directed toward the study of energy transfer in double and triple activated glasses, its manifestations in stimulated emission processes, and equipment development for these studies. Sequential two-step energy transfer was found in a barium crown glass matrix from UO2+ to Nd3+ to Yb3+ and established the necessity of a bridging ion. Both sequential and parallel radiationless energy transfer was observed in a lithium magnesium aluminosilicate glass. Stimulated emission processes in multiple activated glass etalons were observed in the Yb3+ to Ho3+ transfer laser; as much as a tenfold decrease in the Ho3+ laser threshold was found with the incorporation of Yb3+ in the etalon glass. Larger bursts of oscillations from glass etalons were produced by introducing a recoverable loss in the etalon itself; self Q-switching stimulated emission outputs of Er3+, Yb3+, Nd3+, and Ho3+ by utilizing saturable absorption at the respective wavelengths. The simplest type of self Q-switching was observed in silicate glass singly activated with Er3+ at 80°K. Self-Q-switching of Nd3+ stimulated emission was found in Ce3+, Nd3+ activated etalons at low temperatures after the etalon had been exposed to uv radiation. G.G. N67-12647# Naval Research Lab., Washington, D. C. W. H. Vaughan In its NRL Progr. in High-Power Laser Res. 10 Jun. 1966 p 14 (See N67-12645 03-16) CFSTI: HC $2.00/MF $0.50 |