Abstract: The linewidth of a distributed feedback semiconductor laser or a distributed Bragg reflector laser having one or more second order gratings is reduced by using an external cavity to couple the vertical emission back into the laser. This method and device prevent disturbance of the main laser beam, provide unobstructed access to laser emission for the formation of the external cavity, and do not require a very narrow heat sink. Any distributed Bragg reflector semiconductor laser or distributed feedback semiconductor laser that can produce a vertical emission through the epitaxial material and through a window in the top metallization can be used. The external cavity can be formed with an optical fiber or with a lens and a mirror or grating.

Abstract: A method of effecting modifications at the surfaces of materials using low energy ion beams of known quantum state, purity, flux and energy. The ion beam is obtained by bombarding ion-generating molecules with electrons which are also at low energy. The electrons used to bombard the ion generating molecules are separated from the ions thus obtained and the ion beam is directed at the material surface to be modified. Depending on the type of ion generating molecules used, different ions can be obtained for different types of surface modifications such as oxidation and diamond film formation.

Abstract: Linear aromatic polyimides with low dielectric constants are produced by adding a diamic acid additive to the polyamic acid resin formed by the condensation of an aromatic dianhydride with an aromatic diamine. The resulting modified polyimide is a better electrical insulator than state-of-the-art commercially available polyimides.

Abstract: In a system (20) for entering and leaving a space station, a bulkhead (30) divides module (22) into an antechamber (32) and an airlock (34). A space suit (36) has a portable life support system (PLSS) interface (38) on its back. The suit is removably attached to bulkhead (30) by the interface (38) at a hatch (40) in the bulkhead (30). A PLSS (42) is detachably mounted in hatch cover (44), which is pivotally mounted at (46) to move away from the hatch (40) to allow an astronaut (48) to enter the suit (36) through the open hatch (40) and the PLSS interface. After entering the suit (36), the astronaut closes the hatch (44) and attaches the PLSS (42) to the suit (36) by operating control (52) to which glove portion (54) of the suit (36) is attached. The astronaut initiates pumpdown of the airlock (34) with the control (52).