Abstract: A cw CO.sub.2 tunable laser is employed to irradiate an allyl halide selected from allyl chloride, allyl bromide, allyl fluoride, 2-methyl-3-chloropropene, and 2,3-dichloropropene and contained in one or more reaction cells at a predetermined pressure. A predetermined power level from about 25 to 150 watts, an irradiating time from about 0.2 second to about 60 seconds, and a selected radiation line for example P(36), P(32), P(28), P(26), or P(22) (that is resonant with an absorption band of the selected allyl halide) are employed to achieve dissociation of the selected allyl halide and to achieve a laser-induced photochemical synthesis of benzene and substituted benzenes.

Abstract: Disclosed is a method to synthesize Si.sub.3 N.sub.4 from SiX.sub.4 +NX.s3, wherein X is selected from hydrogen and/or fluorine, by laser photochemical reaction (LPR) technique in a controlled atmosphere chamber wherein the reactant gases are maintained at pressures between about 10 and about 200 torr in a molar volume ratio of about 3 of the SiX.sub.4 to about 4 of the NX.sub.3. The LPR method produces the compound Si.sub.3 N.sub.4 at room temperature while employing a pulsed laser or a continuous wave laser.

Abstract: The R.sub.(48) (992 cm.sup.-1) line of a tunable cw multiline CO.sub.2 laser is used to dissociate thiophosgene (CSCl.sub.2) to produce the excited radical, CS*, homogenously in a laser chamber containing premixed O.sub.2. The R.sub.(48) (992 cm.sup.-1) line of the CO.sub.2 laser is resonant with the 2.nu..sub.2 (992 cm.sup.-1) overtone of CSCl.sub.2. This line is strongly absorbed by the CSCl.sub.2 which dissociates (80%) into 2 Cl and CS*. The CS* reacts with the premixed O.sub.2 to chemically produce excited CO which subsequently lases.

Abstract: Disclosed is a method to prepare and coat an optical fiber with Si.sub.3 ub.4. The Si.sub.3 N.sub.4 is synthesized from SiF.sub.4 +NH.sub.3 and/or SiH.sub.4 +NF.sub.3 by laser photochemical reaction (LPR) techniques in a controlled atmosphere chamber. The silicon fiber which is a representative optical fiber is drawn from a preform at about 2000.degree. C. in a standard fiber drawing furnace. Immediately after drawing of fiber, the fiber is passed through a chamber with a controlled atmosphere containing SiX.sub.4 and NX.sub.3 gases, wherein X equals hydrogen or fluorine. A laser is used to irradiate the atmosphere and the Si.sub.3 N.sub.4 is coated on the optical fiber to a thickness of about 0.02-0.20 micrometer which hermetically seals the fiber and enhances and maintains the mechanical strength thereof.

Abstract: A chemical HF or DF laser is obtained by irradiating COF.sub.2 +H.sub.2 /ub.2 in admixture with the R.sub.12 line of a CO.sub.2 laser. The irradiation is accomplished in a laser cavity provided with appropriate Brewster windows, mirrors, and coupling means. The COF.sub.2 is mixed with H.sub.2 or D.sub.2 in a properly conditioned system without reacting. The irradiating by the R.sub.12 line of a CO.sub.2 laser dissociates the COF.sub.2 to form CO+2F* (F* --atom in an excited state). The F* atom then reacts with H.sub.2 /D.sub.2 present to produce HF or DF in an excited vibrational state. The halogen containing molecule then lases.

Abstract: A chemical HCl or DCl laser is obtained by irradiating COCl.sub.2 +H.sub.2 D.sub.2 in admixture with the P.sub.54 line of a CO.sub.2 laser. The irradiation is accomplished in a laser cavity provided with appropriate Brewster windows, mirrors, and coupling means. The COCl.sub.2 is mixed with H.sub.2 or D.sub.2 in a properly conditioned system without reacting. The irradiating by the P.sub.54 line of a CO.sub.2 laser dissociates the COCl.sub.2 to form CO+2Cl* (Cl*-atom in an excited state). The Cl* atom then reacts with H.sub.2 /D.sub.2 present to produce HCl or DCl in an excited vibrational state. The halogen containing molecule then lases.

Abstract: A method for the production of B.sub.10 H.sub.14 by laser induced chemistry is disclosed. A DF laser is used to irradiate a laser reaction cell containing diborane (B.sub.2 H.sub.6). The P.sub.12 (2611 cm.sup.-1) frequency of the 1-0 band of the DF laser is resonant with the .nu..sub.8 (2614 cm.sup.-1) vibrational fundamental of B.sub.2 H.sub.6 and starts a chain reaction producing solid white crystals of B.sub.10 H.sub.14 that condense on the walls of the laser reaction cell. The method is carried out at room temperature. Thus, the chemical engineering is very simple. The B.sub.10 H.sub.14 produced is of high purity and high yield. The production of decaborane-14 from diborane by DF laser induced chemistry (LIC) represents an efficient synthesis of a large polyatomic molecule of high purity by LIC.

Abstract: A process for producing the product NF.sub.4 BF.sub.4 by subjecting gases .sub.3, BF.sub.3, and a gaseous source of a compound which releases fluorine gas when subjected to a tuned CO.sub.2 laser source to cause the product NF.sub.4 BF.sub.4 to precipitate and be collectable. This product can be produced in a closed chamber system or in a continuous flow system at room temperature.

Abstract: A CO.sub.2 laser is used to irradiate a laser cell containing gaseous BCl.sub.3 + H.sub.2 at room temperature (25.degree. C) to produce B.sub.2 H.sub.6. The product is sufficiently stable (no loss of concentration over a period of 72 hours) to permit separating B.sub.2 H.sub.6 and recycling the remaining BCl.sub.3 to obtain high efficiency production of B.sub.2 H.sub.6.

Abstract: Phosgene, COCl.sub.2, an impurity in BCl.sub.3 is dissociated by CO.sub.2 ser radiation that is passed through a stainless steel laser cell with NaCl windows on each end of the cell. The power level of a cw CO.sub.2 multiline laser can be varied to accomplish the irradiation to effectively dissociate the COCl.sub.2 into its dissociation products, substantially CO and Cl.sub.2. The BCl.sub.3, .nu..sub.3 (956 cm.sup.-1) fundamental is resonant with CO.sub.2 (P.sub.20) laser line and strongly absorbs this energy which is followed by an intramolecular V--V transfer of energy to the COCl.sub.2 which results in its dissociation. The gaseous compound C.sub.2 H.sub.4 having combination bands and overtones that match reasonably close to the energy levels of COCl.sub.2 can also serve as a diluent for COCl.sub.2 to effect transfer of energy for dissociation of COCl.sub.2 by cw CO.sub.2 laser radiation.