Optical Module Transceivers Yuav tsum tau calibration

 

Vim li cas Calibration tseem ceeb dua li koj xav

 

Kuv twb pom engineers hla calibration cov kauj ruam nyob rau hauv ntau lawm siab. Lub tswv yim phem. Lub module yuav ua hauj lwm zoo nyob rau hauv lub xeem lub rooj ntev zaum nyob rau hauv chav tsev kub, zaum nyob rau hauv saib zoo kawg nkaus noj qab nyob zoo. Ces nws nkoj. Tau txais kev teeb tsa hauv qhov chaw khaws ntaub ntawv qhov chaw qhov kub thiab txias ntawm 15℃thiab 45℃nyob ntawm qhov txias txias. Qhov ntawd yog thaum cov teeb meem pib.

Qhov hais txogoptical transceiversyog hais tias lawv cov laser diodes yog remarkably rhiab creatures. Qhov kev sib raug zoo ntawm kev tsis ncaj ncees tam sim no thiab cov zis hluav taws xob tsis yog tawm hauv qhov kub thiab txias - nws hloov, drifts, thiab yuav tsum tau them nyiaj. Yog tsis muaj lub Hoobkas calibration kom zoo, lub tshuab hluav taws xob tsis siv neeg tswj hluav taws xob tsis muaj lub tswv yim tias qhov chaw ua haujlwm zoo nyob qhov twg. Lub TOSA (Transmitter Optical Sub-Assembly) xaus ua haujlwm kub dhau, ua kom nrawm nrawm, lossis txias dhau, ua rau lub zog tso tawm tsis txaus rau cov peev nyiaj txuas.

Tus txais rhiab heev calibration nthuav qhia nws cov kev cov nyom. Lub photodetector lub luag hauj lwm sib txawv ntawm cov units-qee zaum loj heev-vim raug tsim nyob rau hauv txoj kev loj hlob ntawm epitaxial. Ib qho qauv yuav xav tau 0.85 A / W txhawm rau ntaus spec thaum nws cov neeg nyob ze ntawm cov kab ntau lawm xav tau 0.92 A / W. General lookup tables tsuas yog tsis txiav nws.

 

Qhov muag Diagram Test

 

Tus neeg twg uas tau ua haujlwm hauv kev kuaj transceiver paub daim duab qhov muag yog txhua yam. Los yog tsawg kawg, nws xav li ntawd thaum lub sij hawm tsim nyog. Cov qauv MSA txhais lub npog ntsej muag- qhov tseem ceeb yog thaj tsam txwv tsis pub zoo li lub hexagon lossis rhombus- uas cov teeb liab tsis tuaj yeem nkag mus. Yog tias koj lub waveform kov lub npog qhov ncauj, lub module ua tsis tiav. Lub sijhawm. Tsis muaj kev sib tham.

Yuav ua li cas tshwm sim thaum lub qhov muag daim duab calibration yog ntau nuanced tshaj qhov pass/fail binary qhia. Tus kws tshaj lij-los yog nce ntxiv, automated calibration software- kho qhov kev hloov pauv tam sim no thiab kev tsis ncaj ncees taw tes rov qab, saib seb lub qhov muag qhib lossis kaw li cas nrog txhua qhov kev hloov pauv. Lub qhov muag dav dua txhais tau tias cov teeb liab zoo dua -rau- suab nrov. Ntau chav rau lub receiver kom paub qhov txawv ntawm cov logical thiab xoom. Lub crossover point yuav tsum zaum ntawm 50%, qhia tias sib npaug lub sij hawm siv nyob rau hauv txhua lub xeev logic.

Jitter accumulates. Qhov ntawd yog qhov phem. Txawm tias me me lub sij hawm tsis paub tseeb sib txuas thoob plaws qhov txuas, noj rau hauv qhov muag muaj nuj nqis qhib kom txog thaum tsis muaj dab tsi tshuav ntawm tus txais. Calibration catches modules nrog ntau dhau intrinsic jitter ua ntej lawv dhau los ua lwm tus qhov teeb meem.

 

Kub Cycling

 

DDM Calibration thiab Dab Tsi Tus lej Tiag Tiag

 

SFF-8472 specification revolutionized transceiver xyuas los ntawm kev txhais cov qauv cim xeeb daim ntawv qhia rau cov ntaub ntawv kuaj mob. Kub, muab hluav taws xob, laser bias tam sim no, TX zog, RX fais fab-tag nrho nkag tau los ntawm qhov yooj yim I²C interface ntawm chaw nyob A2h. Tab sis ntawm no yog qhov kev qhia tshwj xeeb tsis hais txog txaus: cov kev nyeem ntawv no tsuas yog raug raws li lub Hoobkas calibration uas ua rau kev hloov pauv coefficients.

Internally calibrated modules khaws raw ADC qhov tseem ceeb thiab siv qhov ntsuas qhov ntsuas ruaj khov. Cov qauv zoo li ncaj nraim: Calibrated_Value=Slope × Raw_ADC + Offset. Tsis tau txiav txim siab cov nqes hav thiab offset qhov tseem ceeb yuav tsum tau traceable ntsuas cov cuab yeej -calibrated optical zog ntsuas, precision tam sim no qhov chaw, kub- tswj chamber. Ib lub chaw tsim khoom tau hais rau kuv tias lawv qhov chaw ntsuas ntsuas ib leeg raug nqi ntau dua li cov nyiaj hli txhua xyoo ntawm tus kws tshaj lij ua haujlwm. Kuv ntseeg lawv.

Sab nraud calibrated modules thawb qhov nyuaj no rau tus tswv tsev, khaws cov polynomial coefficients rau ntau sophisticated nkhaus haum. Qhov tseeb txhim kho, tab sis ua li cas lub nra ntawm kev suav. Feem ntau lub network keyboards ua haujlwm zoo rau hnub no. Cov cuab yeej qub txeeg qub teg qee zaum nyuaj.

Qhov cuam tshuam rau cov thawj coj hauv lub network: thaum koj qhov kev soj ntsuam xyuas qhia TX lub zog ntawm -3.2 dBm, tus lej ntawd nyob ntawm qhov ntsuas qhov zoo ntawm cov lus nug. Pheej yig transceivers feem ntau qhia ± 1.5 dB variation ntawm lub hwj chim tiag. Hwm modules tuav ± 0.5 dB. Tseem ceeb heev thaum koj tab tom teeb meem kev sib txuas marginal.

 

Wavelength Calibration rau DWDM daim ntawv thov

 

Nthuav wavelength division multiplexing hloov txhua yam hais txog qhov xav tau calibration. Dheev koj tsis cuam tshuam nrog ± 50nm kam rau ua tau nyob rau hauv ib qho -mode SR/LR modules. DWDM channels ua haujlwm ntawm 100GHz lossis txawm tias 50GHz ITU daim phiaj. Ntawm 1550nm, uas txhais tau hais tias kwv yees li 0.8nm sib nrug. Nco koj lub hom phiaj wavelength los ntawm ntau tshaj ± 0.1nm thiab koj tau los ntshav mus rau hauv cov channel uas nyob ib sab, tsim crosstalk uas propagates los ntawm tag nrho cov system.

Tunable transceivers ntxiv lwm txheej ntawm complexity. Lub calibration yuav tsum suav rau wavelength - nyob ntawm lub zog hloov pauv thoob plaws qhov kev sib tw. Ib qho module yuav tsim -1 dBm ntawm 1530nm tab sis tsuas yog -2.5 dBm ntawm 1565nm. Internal lookup tables compensating rau tus cwj pwm no yuav tsum tau characterization ntawm ntau wavelength ntsiab lus thaum lub sij hawm tsim khoom.

Kuv tau poob suav ntawm ntau npaum li cas DWDM xa tawm teeb meem taug qab mus rau qhov tsis txaus wavelength calibration. Cov tsos mob ib txwm tsis meej pem thaum xub thawj- qhov yuam kev tsis sib xws, qhov tsis tau piav qhia BER spikes, qhov kub thiab txias- nyob ntawm tus cwj pwm uas ploj mus thaum koj nqa lub module rov qab mus rau qhov chaw kuaj sim.

 

 

Cov Lus Nug Tam Sim No

Laser bias tam sim no tsim nyog saib xyuas tshwj xeeb. Nws yog qhov parameter feem ntau qhia txog kev noj qab haus huv ntawm lub sijhawm. Ib tug zoo calibrated module pib lub neej nrog bias tam sim no zoo hauv qab lub tswb pib, tawm hauv lub taub hau rau qhov inevitable nce raws li lub hnub nyoog laser. Quantum efficiency degrades. Lub voj APC them nyiaj los ntawm kev thawb ntau dua tam sim no los ntawm diode. Thaum kawg, qhov kev tsis ncaj ncees tam sim no tsoo qhov siab - ceeb toom pib- koj lub teeb liab xaj kom hloov ua ntej qhov txuas mus.

Yog tsis muaj qhov tseeb calibration, qhov kev kwv yees muaj peev xwm ploj mus. Cov lus tshaj tawm tsis zoo tam sim no yuav nyeem 35mA thaum tam sim no tiag tiag yog 42mA. Koj yuav tsis pom lub sijhawm ceeb toom.

 

Production Reality

 

Niaj hnub nimno transceiver factories calibrate ntau txhiab modules txhua hnub. Automation tuav feem ntau ntawm nws-robotic handlers ntsaws modules rau hauv cov ntawv xeem, software algorithms optimizing parameters, tsis siv neeg hla / tsis ua raws li MSA daim npog qhov ncauj. Tib neeg kev cuam tshuam tshwm sim feem ntau yog thaum muaj ib yam dab tsi mus tsis ncaj ncees lawm lossis thaum cov khoom lag luam tshiab hloov pauv nkag mus rau hauv kab.

Lub chaw calibration nws tus kheej yog feem ntau ua nyob ib ncig ntawm ib tug siv receiver uas paub cov yam ntxwv, siab -bandwidth oscilloscope muaj peev xwm ntawm lub qhov muag daim duab tsom xam, ib tug BERT (Bit Error Rate Tester) rau rhiab heev ntsuas, thiab ib tug kho qhov muag spectrum analyzer rau wavelength pov thawj. Kub forcing tshuab tshuab precisely tswj huab cua hla modules thaum lub sij hawm parametric xeem. Tsis muaj dab tsi nyob rau hauv ambient tej yam kev mob.

Yield tus nqi sib txawv wildly nyob ntawm cov khoom complexity. Yooj yim 1G SFP modules tuaj yeem ua tiav 95%+ ua ntej- dhau qhov kev ua tiav zoo. High-speed 400G QSFP-DD modules nrog PAM4 kev hloov pauv? Kuv tau hnov ​​​​cov duab ze dua rau 70% rau qee qhov kev tsim, txawm tias cov tuam txhab tsim cov lej no kom zoo. Cov chav ua tsis tiav yog tau rov ua haujlwm dua -re- kev sib txuas sib txuas, hloov cov khoom tsis raug cai - lossis muab pov tseg tag nrho yog tias qhov tsis xws luag yog qhov tseem ceeb.

Tus nqi siab tsav qee tus neeg muag khoom kom txiav cov ces kaum. Tsawg cov ntsiab lus kub thaum lub sij hawm calibration. Looser txais cov qauv. Lub sij hawm voj voog ceev dua. Cov modules tseem ua haujlwm, technically. Lawv tsuas yog ua tsis tau zoo ntawm cov npoo, thiab lawv poob sai dua hauv kev ntxhov siab.

 

 

Qhov no txhais tau li cas rau Kev Muag Khoom

 

Thaum ntsuam xyuas cov neeg muab khoom xa tawm, cov kev ntsuas ntsuas yuav tsum ua rau koj qhov kev txiav txim siab-tab sis lawv tsis tshua pom hauv cov ntaub ntawv. Nug txog lawv cov cuab yeej calibration traceability. Thov cov ntaub ntawv hais txog qhov kub thiab txias siv thaum lub sijhawm ua tus cwj pwm. Tshawb nrhiav seb lawv puas ua tau 100% kev sim lossis cia siab rau cov qauv. Cov lus teb qhia ntau ntxiv txog module zoo dua li kev lag luam specifications puas tau.

Thib peb- tog tau txais transceivers nyob hauv qhov chaw txaus nyiam ntawm no. Qee cov tuam txhab lag luam nqis peev ntau rau hauv kev tsim kho vaj tse, tsim cov qauv uas phim lossis tshaj OEM zoo. Lwm tus ... tsis txhob. Nqe ib leeg yuav tsis qhia koj qhov twg yog qhov twg. Kev ua tau zoo tshaj qhov kub thiab qhov ntev - lub sij hawm cia siab rau yog qhov sib txawv tiag tiag, ob qho tib si ncaj qha rau calibration zoo thaum tsim khoom.

Qhov tseeb tseem ceeb tseem tsis hloov pauv: ib qho optical transceiver tsuas yog zoo li nws cov calibration. Lub physics ntawm cov khoom siv photonic xav tau nws. Kub dependencies xav tau nws. MSA ua raws li xav tau nws. Leej twg qhia koj calibration yog xaiv los tsis nkag siab txog thev naus laus zis lossis tsis quav ntsej txog koj lub network uptime. Tsis tau txais.