1、 TIA/EIASTANDARDFOTP-126Spectral Characterizations of LEDsTIA/EIA-455-126FEBRUARY 2000TELECOMMUNICATIONS INDUSTRY ASSOCIATIONRepresenting the telecommunications industry inassociation with the Electronic Industries Alliance ANSI/TIA/EIA-455-126-2000Approved: February 2, 2000TIA/EIA-455-126Copyright
2、Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NOTICETIA/EIA Engineering Standards and Publications are designed to serve the public interestthrough eliminating misunderstandings between
3、 manufacturers and purchasers, facilitatinginterchangeability and improvement of products, and assisting the purchaser in selecting andobtaining with minimum delay the proper product for his particular need. Existence of suchStandards and Publications shall not in any respect preclude any member or
4、nonmember ofTIA/EIA from manufacturing or selling products not conforming to such Standards andPublications, nor shall the existence of such Standards and Publications preclude their voluntaryuse by those other than TIA/EIA members, whether the standard is to be used either domesticallyor internatio
5、nally.Standards and Publications are adopted by TIA/EIA in accordance with the American NationalStandards Institute (ANSI) patent policy. By such action, TIA/EIA does not assume any liabilityto any patent owner, nor does it assume any obligation whatever to parties adopting the Standardor Publicatio
6、n.This Standard does not purport to address all safety problems associated with its use or allapplicable regulatory requirements. It is the responsibility of the user of this Standard toestablish appropriate safety and health practices and to determine the applicability of regulatorylimitations befo
7、re its use.(From Standards Proposal No. 3009-A, formulated under the cognizance of the TIA FO-2.3Subcommittee on Electro-Optic Sources, Detectors & Devices.)Published byTELECOMMUNICATIONS INDUSTRY ASSOCIATION 2000Standards and Technology Department2500 Wilson BoulevardArlington, VA 22201PRICE: Pleas
8、e refer to current Catalog ofEIA ELECTRONIC INDUSTRIES ALLIANCE STANDARDS and ENGINEERING PUBLICATIONS or call Global Engineering Documents, USA and Canada(1-800-854-7179) International (303-397-7956)All rights reservedPrinted in U.S.A.Copyright Telecommunications Industry Association Provided by IH
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10、entering into a license agreement. For information, contact:Global Engineering Documents15 Inverness Way EastEnglewood, CO 80112-5704 or callU.S.A. and Canada 1-800-854-7179, International (303) 397-7956Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for R
11、esaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-126iFOTP-126Spectral Characterization of LE
12、DsContents1. Introduction. 11.1 Intent. 11.2 Accuracy and precision 11.3 Hazards 11.4 Applications 12. Applicable documents 23. Apparatus . 23.1 Connector or ferrule holder 23.2 Calibrated wire holder 23.3 Calibrated wire set 24. Sampling and specimens. 35. Procedure. 36. Calculations or interpretat
13、ion of results 57. Documentation . 67.1 All applications . 67.2 United States military 68. Specification information 7Annex A 8Annex B 9Annex C 11Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without lice
14、nse from IHS-,-,-TIA/EIA-455-126ii(This page left blank)Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-126iiiFOTP-126Spectral Characterization of LEDsForeword(This
15、Foreword is informative only and is not part of this Standard. )From TIA Project No. 3009, formulated under the cognizance of TIA FO 6.5, Subcommitteeon Electro-optic Sources, Detectors and Devices.This FOTP is part of the series of test procedures included within Recommended StandardTIA/EIA-455.The
16、re are three annexes.Key words: light-emitting diode, optical spectrum, spectral width.Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-126ivThis page left blank.Copy
17、right Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-1261FOTP-126Spectral Characterization of LEDs1 Introduction1.1 IntentThe intent of this test procedure is to measure the
18、central wavelength, peak wavelength, and thespectral width (RMS and FWHM) of a semiconductor light-emitting diode (LED) using a dispersivespectrophotometric method (that is, using a revolving diffraction grating) or other suitable methods.NOTE: RMS is the Root Mean Square and FWHM is the Full Width
19、Half Maximum (3 dBdown).1.2 Accuracy and precisionThe uncertainty of the procedure is determined by the uncertainty of the optical spectrum analyzerand the number of data points selected. The precision of the method is determined by the precisionof the optical spectrum analyzer and the resolution se
20、tting used. The precision of this proceduremay be enhanced by averaging several sweeps. 1.3 HazardsThis procedure involves measurements of energized optical sources. Exercise care to avoidpossible eye damage. Do not look into the end of an energized fiber directly or with a magnificationdevice.1.4 A
21、pplicationsThis procedure is applicable to all light-emitting diodes.Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12622 Normative referencesTest or inspection req
22、uirements may include, but are not limited to, the following references:EIA/TIA-455 Standard Test Procedures for Fiber optic Fibers, Cables,Transducers, Sensors, Connecting and Terminating Devices,and Other Fiber Optic Components3 Apparatus3.1 Calibrated optical spectrum analyzerThe optical spectrum
23、 analyzer periodically resolves the spectral distribution in the optical output ofLEDs. The spectral distribution periodically resolved is displayed on the CRT display of the opticalspectrum analyzer. The optical spectrum analyzer typically has a connector receptacle on the frontpanel for connection
24、 to an optical fiber.3.2 Power suppliesPower supplies shall have a stable output voltage (not greater than 5 percent variation) compatiblewith the test specimen.3.3 Signal sourceThe signal source shall provide the test specimen with an input signal as specified in the detailspecification.3.4 Fiber o
25、ptic jumper cableOne end of the fiber optic jumper cable shall be terminated with a connector compatible with theoptical spectrum analyzer. The other end shall be terminated with a connector compatible with thetest specimen or a fiber end properly prepared for coupling to the test specimen. The fibe
26、r opticjumper cable shall be less than 10 meters in length.Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-1263Copyright Telecommunications Industry Association Prov
27、ided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12644 Sampling and specimensThe test specimen shall consist of one of the following: 1) an LED chip, 2) a packaged LED with anarrangement to couple output light into a fib
28、er pigtail, or 3) a fiber optic transmitter using an LED,with a pigtail terminated with a connector. The test specimen mounting (including heat sinks) shallbe as specified in the referencing document.5 ProcedureNOTE: If an LED chip or packaged LED is being tested, take care to prevent ambient lightf
29、rom affecting the measurement.5.1 Unless otherwise specified, make measurements under the standard ambient conditions ofEIA/TIA-455, except for the temperature. Maintain ambient temperature at 23 oC + 2 oC.5.2 Apply the DC bias current or modulated signal specified in the referencing document to the
30、 testspecimen. Allow sufficient time (per manufacturers recommendation or as specified in thereferencing document) for the test specimen to reach a steady state temperature.NOTE: If a modulated signal is used, the modulation rate should be high enough that theaverage power measured by the optical sp
31、ectrum analyzer at each wavelength isstable.5.3 Turn the optical spectrum analyzer on and allow it to warm up (see the manufacturer srecommendations).5.4 Connect the optical output of the test specimen to the optical input connector of the opticalspectrum analyzer. For pigtailed test specimens this
32、may be accomplished by directly connectingthe end of the optical fiber pigtail into the optical spectrum analyzer. For bare LED chips orconnectorized test specimens this may be accomplished by connecting the fiber optic jumper cablebetween the test specimen and the optical spectrum analyzer.NOTE: In
33、 some cases, a significant amount of optical power may be present in the fibercladding. A mandrel wrap may be applied to the fiber optic jumper cable or theoptical fiber pigtail to remove power from the fiber cladding.Copyright Telecommunications Industry Association Provided by IHS under license wi
34、th EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12655.5 Adjust the optical spectrum analyzer controls as follows:a. Using the resolution control, select a resolution 11), andPois the summed linear output optical power, that isNOTE: Porepresents th
35、e total linear output optical power from the source when the spacingbetween adjacent wavelengths is the same as the wavelength resolution of theoptical spectrum analyzer.P(nW) = 10( 0.1*P(dBm)+6 )coi=1Ni i=1Ppoi=1NiP =pCopyright Telecommunications Industry Association Provided by IHS under license w
36、ith EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12676.4 Using the wavelengths and corresponding linear optical powers (nW), calculate the rmsspectral width as follows:where: cis the central wavelength andi, pi, N, and Poare defined as above.)p P1
37、=2ciiN1=io21(Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-1268See Annex B for an example RMS spectral width calculation.6.5 Calculate the FWHM spectral width as :
38、where: uis the upper 3 dB wavelength andlis the lower 3 dB wavelength.7 Documentation7.1 All applications Report the following information for each test:7.1.1 Date and title of the test.7.1.2 Identification of procedure (FOTP-126).7.1.3 Identification of the test specimen (fiber optic transmitter or
39、 LED).7.1.4 Peak wavelength.7.1.5 Individual wavelengths and output optical powers used in central wavelength and RMSspectral width calculations.7.1.6 Central wavelength.7.1.7 RMS spectral width.7.1.8 Full width half maximum spectral width.7.1.9 Ambient temperature.7.1.10 Spectrum analyzer resolutio
40、n, reference level, span limits and vertical scale settings.FWHM u l= - Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12697.2 United States military United States
41、military applications require that the following information also be reported for eachtest. For other (nonmilitary) applications, this information need not be reported but shall be availablefor review upon request:7.2.1 Test personnel.7.2.2 Brief description of the test apparatus and date of latest
42、calibration.8 Specification informationThe following information shall be specified in the Detail Specification:8.1 Supply voltage(s) and/or current(s).8.2 Modulation signal and bias conditions.8.3 Optical output measurement conditions, including details of fiber jumper cable or fiber opticpigtail.8
43、.4 Recommended device warm-up time for temperature stabilization.Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12610Annex A (informative)Comparison between this FO
44、TP and IEC or ITU/T requirementsA.1 IECThere are no known IEC documents on this topic matter.A.2 ITU/TThere are no known ITU/T documents on this topic matter.Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted
45、without license from IHS-,-,-TIA/EIA-455-12611Annex B (informative)Example central wavelength and RMS spectral width calculations.B.1 The output optical power spectrum (in dBm) of a single-mode fiber-coupled, high-power,InGaAsP edge-emitting LED is shown in Figure B1. Columns 1 through 3 in Table B1
46、 show theeleven points selected from the spectrum according to Section 5.8. Column 4 shows the opticalpower converted from logarithmic to linear units using the equations in 6.1. The products shownin columns 5 and 6 and the summations shown in the row labeled “SUM“ are used to calculate thecentral w
47、avelength, c, and the RMS spectral width, , according to the equations in 6.2 and 6.3,respectively. The bottom two rows show the calculated central wavelength and RMS spectral widthfor this LED.Figure B1. Example LED optical spectrum.-50 -45 -40 -35 -30 -25 -20 Optical power (dBm)1200 1250 1300 1350
48、 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA/EIA-455-12612Table B1. Measurement data for example LED spectrumData point Wavelength Power(dBm)Power(nW)piipi(ic)2123456789101112261243126012771294131113281345136213791396-44.0-39.0-33.0-28.0-24.0-24.5-27.0-31.0-35.0-39.0-44.0401265
