J SEP 232002 ©H o 9, soo oh « 1,30/4-9 202-00 & TechBriefs = National Aeronautics and Elecirenic Components and Circuits Electronic Systems Physical Sciences Materials Computer Programs Mechanics Machinery Fabrication Technology Mathematics and information Sciences vt9® O0 00060 Life Sciences Am 2003000034F 02-09 Fa September 2002 INTRODUCTION likely to be transferable ac’oss industrial, regional, or disciplinary lines and are issued to encourage Availability of NASA Tech Briefs and TSPs Requests for individual Tech Briefs or for Technical Support Packages (TSPs) announced herein shobe uacidlresdsed to National TechnTorainsfoer gCeynt er TelephonNeo . (800) 678-6882 or via World Wide Web at www2.nttc.edu/leads/ Please reference the control numbers appearing at the end of each Tech Brief. information on NASA's Commercial Technology Team, its documents, and services is also available at the same facility or on the World Wide Web at www.nctn.hq.nasa.gov. Commercial Technology Offices and Patent Counsels are located at NASA field centers to provide technology-transfer access to industrial users. Inquiries can be made by contacting NASA field cen- ters and program offices listed below. NASA Field Centers and Program Offices Ames Research Center John F.K ennSpeeced Cyent er NASA Program Offices Carolina Blake Jim Alibert At NASA Headquarters there are seven major program offices that (650) 604-1754 or (321) 867-6224 or Gevelop and oversee technology projects of potential interest to industry: George (301) 286-5810 or Nasa. gov Je: Propulsion Laboratory Merle MicKenze (818) 354-2577 or mene mcxenzeG@g) NASA Tech Brets. Saptemnb2e0r0 2 NASA Tech Brnefs, March 2000 S TechBriefs Space Administration 5 Electronic Components and Circuits 9 Electronic Systems 13 Physical Sciences 21 Materials 27 Computer Programs 31 Mechanics 37 Machinery 41 Matheand mInaformtatiion cScisenc es |2|#6 O@)1|\ O 9 @) 45 Life Sciences This document was prepared under the sponsorstup of the National Aeronautics and Space Administration. Neither the United States Government nor any person acting on behalf of the United States Government assumnes any lability resulting from the use of the information Contained in ths Gocumnent, or warrants thet such use will be free from privately owned nights. 4 LANG PACE Electronic Components and Circuits Hardware, Techniques, and Processes 7 Multiple-Pump Lasers 7 Clamps for Testing Cable Shields and Connector Shells NASA Tech Bnets, Septernber 2002 5 6 BLANK PAGE Multiple-Pump Lasers Fiber-optic coupling ise xploited to increase reliability NASA's Jet Propulsion Laboratory, without excessive Complexity. Pasadena, California been common practice to pump a Nd:YAG Crystal by use of a single Ghode laser How- ever, Giode lasers are nnt relable enough to Support long-life, high-pcwer operation. if # To Na YAG Crystal mustiple Gode lasers could be used to pump a single Nc: YAG crystal, then laser operation would br less degraded by the Geteonr faiolurer ofa a stinglie Giooden las er. One alternative scheme for coupling ight from multiple laserp-umcpsi iontod ae si n- gle Na: YAG crystal would involve the inte- Qration of mufipie laser clodes, along with relatively Complopiticcs, aontto ea sding le Light From Multiple Pump Lasers is coupled through optical fibers into a ferrule, wherein the Chip. in such an arrangeimte wonultd ,no t indipumvp bieamds eure acomlbine d. be possible to change the number of pumps. Monsover, the pumps would not be bines the multiple pump beams into a sin- this invention. inquines concemmnng nghits for isoflroam etaceh odthe r, so that faiureo f gle beam aimed into the Nd:YAG crystal. itsc ommusee shrouldc bei adadreslsed to The failure of one laser diode does not intelleAscsettsu Oafflic e affect the operation of the others, and the JPi. bgt from the others continues to pump Mail Stop 202-233 the Nd:YAG crystal. 4800 Oak Grove Drive This work was done by Serge Dubovitsky, PasadeCnA a91,10 9 Jerry Viuidler, and Duncan Liu of Caltech for (818) 354-2240 tively simple optics. The output ends of the NASA's Jet Propulsion Laboratory. E-mail: ipgroup@jpl_ nasa.gov fibers of multiple independent fiber-cou- Further inforim caonttaiineod nn a TSP Refer to NPO-30353, volaund mnuembe r piled laser diodes are bundled together in a [see page 1} of this NASA Tech Briefs issue, and the ferme (see figure). A gradient-index-of- in accowrith dPubalic nLawc 9e6-51 7, page numbe retraction (GRIN) lens in the ferrule com- the contractor has elected to retain ttle to Clamps for Testing Cable Shields and Connecior Shelis Connector test amps (CTCs) are ciesn>- jaw mounted onto a manualy operated applwheire ca staandatrd ialigoatorn cli p is ng @ectica connectors Gesigned for use in ratcheting Clamp that can be released by fin- not sufficiert. testing electrical continuity for the back- Qe pressure on a lever CTCs can be made This work was done by Kenneth A Gel ot a connector at one end of a shwaidied with jaws of various siz3s and shapes to fi a Reaume of United Space Alliance for @ectrica cable, trough the cable swakd, to vanofe cotnneyct or shels or anpicatiors. Kennedy Space Center. for further nfor- te bade? at fe ote ard of te cable. Each CTC is machined to alow connection mation, please contact Phi Restivo, 1150 CTCs increase the refabiity of testing of of a standard banane-jack-ttiepstp eradd . Garmin Ave., M/S: USH-100D . Houston, shieided electrical cables beyond thut Once the CTC is Gia nped into place, ore TX 77058, Tal. No. (321) 212-6125, E-rial: actwevable with aligator caps flor which sult- end of the test lead is neared rio the jaw Philip. G. Restivo@USAHO. UnitedSpace aie atlachnet ports offen carrot be ao te othe into ary ype of test equp- Aliance.com found. Each CTC consists of a conductive ment required. CTCs can be utiized in any KSC-12286 NASA Tech Bnets. Septembe20r0 2 BLAMES PAGE Electronic Systems Hardware, Techniquesa,nd Processes 11 Generalized Pre-Processor for Block and Convolutional Codes 11 improved Transponder for Earth’SpacCeomcmurniacaftito n 12 Making Audible Alarms More Noticeable in Noisy Environments NASA Tech Briefs. Sapternt2e0r0 2