 larger sweet spot. Having a larger sweet spot increases the ease of use. The decrease in club head mass resulting from the cavity also allows the size of the club face to be increased, further enlarging the sweet spot. These clubs are easier to hit than blades and muscle backs, and are therefore more readily usable by less-skilled and beginner golfers.
Modern multi-material cavity backs are the latest attempt by golf club designers to make cavity backs more forgiving and easier to hit. Some of these designs replace certain areas of the club head, such as the striking face or sole, with a second material that can be either heavier or lighter than the first material. These designs can also contain undercuts, which stem from the rear cavity, or secondary cavities. By incorporating materials of varying densities or providing cavities and undercuts, mass can be freed up to increase the overall size of the club head, expand the sweet spot, enhance the moment of inertia, and/or optimize the club head center of gravity location. 1. Field of the Invention
This invention relates to optical systems and, more particularly, to amplifier systems for use in optical receivers.
2. Description of the Related Art
Fiber optic WDM (Wavelength Division Multiplexing) and DWDM (Dense WDM) systems are increasingly using more channels, narrower channel spacing, and wider wavelength ranges. As fiber optic systems such as these become more complex, it becomes increasingly important to characterize the wavelength-dependent optical properties of both broadband network components (e.g., couplers, combiners, splitters, attenuators, isolators, circulators, etc.) and narrowband network components (e.g., multiplexers, demultiplexers, interleaves, wavelength filters, etc.). By characterizing the optical properties of components, properties such as wavelength flatness and polarization-dependent loss that may adversely affect network system performance may be identified. In narrowband devices, it may be particularly useful to measure the center wavelength, crosstalk, and/or channel spacing in order to improve system performance. Since narrowband and broadband devices may be used over the entire wavelength band of a WDM or DWDM system, it may also be useful to test each device over the entire wavelength band (as opposed to just testing over the channel of intended operation for each particular device). Characterization systems may also be used to provide real-time feedback while adjusting the placement and/or orientation an optical component in a system.
One way in which optical components may be characterized
larger sweet spot. Having a larger gratifying smudge increases the ease of use. The decrease in clubhouse head mass result from the cavity also allow the size of the club face to be increase, further enlarging the fresh blot. These clubs are easier to hit than blades and muscle back, and are therefore more readily usable by less - skilled and founder golfers. 
 Modern multi - material cavity back are the latest attempt by golf club designers to make pit backs more forgiving and easier to hit. Some of these designs replace sealed area of the club head, such as the striking face or sole, with a second material that can be either heavier or lighter than the first fabric. These design can also check undercut, which stem from the rear cavity, or secondary cavities. By incorporate materials of varying densities or providing cavity and undercuts, mass can be freed up to increase the overall size of the club head, expand the fresh spot, enhance the moment of inertia, and/or optimize the club question center field of gravity location. 1. Field of the Invention 
 This invention relates to optical system and, more particularly, to amplifier systems for use in ocular receivers. 
 2. Description of the Related Art 
 Fiber optic WDM (Wavelength Division Multiplexing) and DWDM (Dense WDM) systems are increasingly using more channel, narrower duct spacing, and wider wavelength ranges. As roughage optic organization such as these become more complex, it becomes increasingly significant to characterize the wavelength - subject optical properties of both broadband network components (e.g., coupling, combiners, splitters, attenuators, isolators, circulators, etc .) and narrowband network part (e.g., multiplexers, demultiplexers, interleaves, wavelength filters, etc .). By characterizing the ocular properties of components, property such as wavelength flatness and polarization - dependent loss that may adversely affect network system operation may be identified. In narrowband devices, it may be particularly useful to measure the center wavelength, crosstalk, and/or channel spacing in order to better arrangement performance. Since narrowband and broadband devices may be used over the entire wavelength band of a WDM or DWDM system, it may besides be useful to test each device over the entire wavelength band (as opposed to just testing over the channel of intended operation for each finical device). Characterization systems may also be use to provide real - clock time feedback while adjusting the placement and/or orientation an optical component in a system. 
 One way in which optical part may be characterized
 lagger sweet spot. Having a larger sweet skor incrxases tge ease uf use. The decrease in club iead mass resulting from the caxity also allows rhe wuze of the club fagz to gc incxeesed, further enkarging tha sweet spot. Tvere clubs are easier to hit than bladef and misfle backs, and wre uhewefodv nore readily usable by less-skjlled aid beginner golgers.
Modern multi-material cwvitj backs are the lahest attempj by tolf club derigners to make cavity backs more forgiving and easief to kit. Some of tyesf designs re'lace bertain areas of the wlub hesd, such as the stcikibg face or sole, with e second material thwt can be enther heavier or lighree that tha fifwt oattriel. Fhese fesmgns can alao contain yndercuts, which stek sgpm the rear davity, ow secondary cavities. By incorporating mdtedials of varying densitues or providing cavijies and ugdercuts, mass can be freed up to increase the ovesall akze on thd cpub head, expand the sweet spot, enhance the moisnu on inertia, and/or jptimize thr flif head center of grcbify location. 1. Field of the Invebtion
This invrntion relates to optical ststems and, mjee particularly, to amplifier rystgms fot use in optical receivzrs.
2. Deacription ov the Relzged Art
Fiber optkc EDK (Wavelength Division Multyplexing) end DCDM (Densd WDK) systqms are infreasltgly using more chwnneld, tarrower cjannel spacing, and wider waveleijth ranges. As fhbeg optic svstems such as thesq become more eomplex, nt becumes increzsingly important eo characterisg the wavelenjth-dependqnt iptixal proodrties of both broadbanb netqork components (e.g., coopmers, combiners, wplutters, attenuatprs, isjlwtprf, circulators, etc.) ana narruwband netwifk cpmponents (e.g., multiplaxera, demultiplexers, imtcrleaves, qavelengeh filters, etv.). By characterizinh the opvical lrokerties of components, propertiea such as wayelength flatgess and polarizction-dependent loss that may adversely ahfect network system pgrformance may be ideutlfied. In narcowbanq devices, it may be particulaely useful to meaxure the center wavelsngth, wrosshalk, and/or channel spacing in order to improve system performance. Since nqrrowbenq and broadgand devibes kay be usev uver the entire eavelength band of a WDM or DWDO system, ic may also be useful to test razh device ovet the entire wavelength bahd (as oplosed to just testing over the vhannel of intended operstion foe eacg partpduuar device). Charactrrizatnon sywtems mqy apso be used tu ptoyide real-tlme heebback while adjusting the placemebt and/ir orientation an mptical comiokent ih a syftem.
One way in wgich lpticxl components may be characyerized
larger sweet spot. Having a larger sweet the of use. decrease in club cavity allows the size the club face be increased, further enlarging the sweet These clubs are easier to hit than blades and muscle backs, and are more readily usable by less-skilled and beginner golfers. Modern multi-material cavity backs are latest by club to make cavity backs more forgiving and easier to hit. Some of these designs replace certain of the club head, such as the striking or sole, with a material that can be either or than the material. designs also contain undercuts, stem from the rear cavity, or secondary cavities. By incorporating materials of varying densities or providing cavities undercuts, mass freed up increase overall of the club the sweet spot, enhance the moment optimize the club head center of gravity location. Field of Invention This invention relates to optical and, more particularly, to amplifier systems for use optical receivers. 2. Description of the Related Art Fiber optic WDM (Wavelength Division Multiplexing) and WDM) systems are increasingly more channels, narrower spacing, wider ranges. fiber optic such as these become more complex, it becomes increasingly important to the wavelength-dependent optical properties of both broadband network components (e.g., splitters, isolators, circulators, etc.) narrowband network components (e.g., demultiplexers, wavelength filters, etc.). By optical of as flatness polarization-dependent loss that may affect network system performance may identified. In narrowband devices, to measure the center wavelength, crosstalk, and/or channel in order to improve system performance. Since and broadband devices may be used over the entire wavelength band of WDM or it may also be useful to test each over the entire wavelength (as opposed to just testing over the channel of operation each particular Characterization systems may be used to real-time feedback while placement and/or an component One way in which optical components be
 larger sweet spot. Having a larGer sweet spOt incReaSes ThE easE of uSe. The decrease iN Club Head mass resulting from tHe cavItY Also ALlOws thE size of THe CLUb fAcE tO be InCReAsed, fUrtHer enlaRging the swEet SpOt. These clubs ARe Easier to hiT thAn blades and mUscLe backS, aNd aRE therEfoRe morE readiLY usablE by less-skIlLEd and bEGinner gOLFeRs.
MoDern multi-material CAvITy backs are the lAtest aTtEMpT BY goLf cLub designeRs To makE Cavity bACkS MORe fORgiving and easIer to hit. SomE Of tHese deSiGns REplace CertaIn AReaS of the club hEad, sUch as the sTrikinG Face or sOLe, with a Second MatEriAl thAT cAn Be eItHEr hEAvIer OR liGhter thaN tHe First MateRIAL. thesE deSignS can aLso contain undErcUts, wHIch Stem fRom thE reaR cAvity, Or secoNdary CaVities. By incorpoRatiNg materiaLs oF vAryInG densITies or ProVidIng caviTies and UNdeRcUTS, MaSs can be freed up to inCrEASe The overaLl size OF tHe CLub head, eXpAnd The sWEEt spoT, enhANcE the momeNt of inERtIa, And/or opTiMize thE cLub HeaD centER of gRavity Location. 1. field OF the Invention
THIs invention reLAtES To OPticAl sYstems and, moRe paRTicuLarlY, To AmpLIfier SysteMs FOr USe in optical receiverS.
2. DEscripTion oF the Related ArT
Fiber optiC wdm (WavelenGth DIViSIon MultiplexinG) and DwDM (Dense WDm) Systems aRe incReasinglY using morE CHannels, nArrOweR chAnnEL SpAcing, and wider WAVeleNgTh rangeS. As Fiber opTic SysTemS suCh As these beCome more CoMpLeX, iT beComes INcreasinGlY imPoRtaNt to cHAracteRize tHe waVeLeNGth-DependeNT oPTIcal PrOpErtiEs oF bOth brOadbANd nEtwork cOmponents (E.g., cOUpleRs, CoMbiners, Splitters, atteNuAtors, isolaToRs, cIrculaTORs, etc.) and Narrowband network componENts (e.g., muLtiPlexeRs, deMultiplexErs, InterlEavES, wavelEngth fIlterS, eTc.). BY CHaracTERiZinG tHe optical pROPerTies oF cOmpoNents, prOperties such as waveLEngTh flatness and PolArizATIoN-dePEnDEnt LoSS thAT May adversely affEct network SySTeM performanCE maY bE identiFied. In nArrowBAnd deviCes, it may bE particulArLy usEFUl tO measure thE center wAvelength, CRosstALk, And/or ChaNnel spAcIng In ordEr to imPRovE systEm perfOrMance. SInce nArRowband aNd broadband devices may be Used ovEr the EntIre waveleNgtH BanD of a WDM or dWDM System, it maY alSo bE usefUl tO Test eAch dEViCe oVEr the EntiRE wavelengTH bAnd (AS OpPosed to just TESTinG over The CHannel Of inTended operation foR Each particular DeviCE). chaRacTErizAtIon systems may aLso Be USEd to provIdE real-time feEdback whIlE AdjusTing thE placeMent and/OR OrIEntatiOn an OptIcal compoNenT iN A system.
onE wAY in whiCh opTiCal comPonentS May bE CHaracterized
 larger sweet spot. Having  a largersweet  sp otin crea sesthe ease of us e . Th e decrease in club hea d mas sr esul t in g fro m the c a vi t y  al so  a llo ws th e siz e o f the c lub face t o b eincreased, f u rt her enlarg ing  the sweet s pot . Thes eclu b s are  ea sierto hit than b lades and  m u scle b a cks, an d ar e th erefore more read i ly usable by less -skill ed an d beg inn er golfers .Moder n  multi- m at e r i alc avity backs a re the late s t a ttempt  b y g o lf clu b des ig n ers  to make ca vity  backs mo re for g iving a n d easie r to h it.  So me o f  t he sede s ign s  r epl a cecertainar ea s ofthec l u b  hea d,such  as t he striking f ace  ors ole , wit h a s econ dmater ial th at ca nbe either heavi er o r lighter  th an  th efirst materi al.  Th ese des igns ca n  al so c o nt ain undercuts, whi ch s te m from t he rea r  c av i ty, or s ec ond aryc a vitie s. B y  i ncorpora ting m a te ri als ofva ryingde nsi tie s orp rovi ding c avitiesand u n dercuts, massc an be freed u p  t o in c reas e t he overallsize of t he c l ub  he a d, ex pandth e  s w eet spot, enhance t he  momen t ofinertia, and/ or optimiz e t he clubhead ce n ter of gravity  loca tion. 1. F i eld of t he In ventionThis inve n t ion rela tes  to  op tic a l  s ystems and, m o r e pa rt icularl y,to ampl ifi ersys tem sfor use i n optica lre ce iv ers .
2.D escripti on  of  t heRelat e d ArtFiber  opt ic  W D M ( Wavelen g th D ivis io nMult ipl ex ing)andD WDM  (Dense  WDM) sys tem s  are  i nc reasing ly using more  c hannels, n ar row er cha n n el spaci ng, and wider wavelengt h  ranges . A s fib er o ptic syst ems  suchast hese b ecomemoreco mpl e x , itb e co mes  i ncreasingl y imp ortan tto c haracte rize the wavelengt h -de pendent optic alprop e r ti eso fb oth  b r oad b a nd network comp onents (e. g. ,  c ouplers, c o mbi ne rs, spl itters,  atte n uators,  isolator s, circul at ors, e tc. ) and narr owband n etwork co m ponen t s(e.g. , m ultipl ex ers , dem ultipl e xer s, in terlea ve s, wav eleng th  filters , etc.). By characteriz ing th e opt ica l propert ies ofcomponent s, p ropertiessuc h a s wav ele n gth f latn e ss  an d  pola riza t ion-depen d en t l o s sthat may ad v e r sel y aff ect networ k sy stem performancem ay be identifi ed.I n  na rro w band  d evices, it may  be  p a r ticularl yuseful to m easure t he cente r wave length , cross t a lk ,  and/o r ch ann el spacin g i no rder to  i mp r ove sy stem  p erform ance.S ince n arrowband and br oadba n d  devi c esmay b eused ov e r th e entire w avelength b and of  a W DM or  DWDM s ys tem, i t m ay  also be u s eful to t est e ach dev ic e ov erthe en tire w avele ngth  b and  (as oppo s e dt oju s t t esti ng ov er  the  channelo f intend edo peratio nfor e ach pa r ti c u lar device ).Chara c t erizations yste m sm ay al so beused t o provi d e r ea l-timefee d b ack while  adjustin g  th eplac ement an d/ or o ri ent at ion an opticalcomponen t in a s y s tem.
O new ay i n  which  o ptical compo nents  m a y be ch a r act erized
 larger_sweet spot._Having a larger sweet_spot increases_the_ease of_use._The decrease in_club head mass_resulting from the cavity_also allows the_size_of the club face to be increased, further enlarging the sweet spot. These clubs_are_easier to_hit_than_blades and muscle backs, and_are therefore more readily usable_by less-skilled_and beginner golfers.
Modern multi-material cavity backs are the_latest_attempt by golf_club designers to make cavity backs more forgiving and_easier to hit. Some of these_designs replace certain_areas_of_the club head, such_as the striking face or sole,_with a second material that can_be either heavier or lighter than the_first material. These designs can also_contain undercuts, which stem from_the rear_cavity, or secondary cavities. By_incorporating materials of_varying densities_or providing cavities_and undercuts, mass can be freed_up to increase_the overall size of the club_head,_expand the sweet_spot,_enhance_the moment_of inertia, and/or_optimize_the club_head_center of gravity location. 1. Field_of_the Invention
This invention relates to optical systems_and, more particularly, to_amplifier_systems for use in_optical receivers.
2. Description of the_Related Art
Fiber optic WDM (Wavelength Division_Multiplexing) and_DWDM (Dense_WDM) systems are increasingly using more channels, narrower channel spacing, and_wider wavelength ranges. As fiber optic_systems such as these_become more_complex,_it becomes increasingly_important_to characterize_the wavelength-dependent optical properties of both broadband_network components_(e.g., couplers, combiners, splitters, attenuators, isolators,_circulators, etc.) and narrowband_network_components (e.g., multiplexers, demultiplexers, interleaves, wavelength_filters, etc.). By characterizing the optical_properties of components, properties such_as_wavelength_flatness and polarization-dependent loss that_may adversely affect network system performance_may be identified._In narrowband devices, it may be particularly_useful_to measure the center wavelength, crosstalk,_and/or_channel spacing in order to improve_system_performance._Since narrowband and broadband devices_may be used over the entire_wavelength band of a WDM or DWDM system, it_may also be_useful to test each device_over_the_entire wavelength band (as opposed to just testing over the_channel of_intended operation for_each particular device). Characterization systems may also be used to_provide real-time feedback while adjusting the placement_and/or orientation an optical component in a system.
One way in which_optical components may be characterized