1、TIA DOCUMENT FOTP 106 Procedures for Determining Threshold Current of Semiconductor Lasers ANSI APPROVAL WITHDRAWN JUNE 2003 NOVEMBER 1992 TELECOMMUNICATIONS INDUSTRY ASSOCIATION NOTICE TIA Engineering Standards and Publications are designed to serve the public interest through eliminating misunders
2、tandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for their particular need. The existence of such Publications shall not in any respect preclude any
3、 member or non-member of TIA from manufacturing or selling products not conforming to such Publications. Neither shall the existence of such Documents preclude their voluntary use by non-TIA members, either domestically or internationally. TIA DOCUMENTS TIA Documents contain information deemed to be
4、 of technical value to the industry, and are published at the request of the originating Committee without necessarily following the rigorous public review and resolution of comments which is a procedural part of the development of a American National Standard (ANS). Further details of the developme
5、nt process are available in the TIA Engineering Manual, located at TIA Documents shall be reviewed on a five year cycle by the formulating Committee and a decision made on whether to reaffirm, revise, withdraw, or proceed to develop an American National Standard on this subject. Suggestions for revi
6、sion should be directed to: Standards Page 4 All cured film specimens shall have flat, parallet surfaces. Thickness variation, defined as (Maximum-Minirnurn)/AverageX100, shall be less than 5%; if such a variation is not achievable using the material under investigation at the desired thickness, use
7、 an average of ten uniformly spaced thickness measurements in the absorbance calculation. When viewed with the unaided eye, the films shall also be free from surface and internal contamination, and of bubbles. Most film samples can be cut with ordinary scissors from a film sheet. The specimens shall
8、 be cut to fit in the film holder, and be at least 30% larger than the spectrophotometer beam geometry. Thin film specimens can be applied, using a spin-coating or similar technique, directly to one of the quartz windows. 4.2 Film Thickness Measurement Measure the coating thickness of all specimens.
9、 The precision and accuracy of thickness measurements shall be 1% and 5%, respectively. If a micrometer or similar single point measurement technique is used, five uniformly spaced thickness measurements shall be averaged (unless the thickness variation is greater than 5%, in which case IO measureme
10、nts shall be averaged). If a profile trace is taken, the average thickness of three uniformly spaced traces shall be averaged, Care should be taken to not compress the film during thickness measurements. This average thickness will be used in 6.2 to calculate the modified extinction coefficient. 5.
11、PROCEDURE 5.1 Follow the spectrophotometer start.up procedure, inctuding warm-up time, and the following intiallzation settings: NOTE: Operation must be in the Scan Mo-, and the entire optical compartment shall be purged with high purity nitrogen (99,999% or better in purity, with a maximum of 5 ppm
12、 of Moisture and Oxygen content, and a maximum of 1 pprn of Hydrogen and Hydrocarbon content). For further information on the use of a recording spectrophotometer, refer to Procedure? 8 of ASTM O 1003 - 61 .) 5. i ,1 Requirsmenb (untess othemise specified in Detail Specification): 5.t .i .1 Ordiniat
13、e mode: Ab (Absorbance) 5.1.1.2 Abscssa mode: Wavelength 5.1 .I .3 5.1.2 Rtmmmenda4ions; Abscssra range: 600 to 1700 nm 5.1 2.1 5,s 2.1 5.1 2.3 5.1 2.4 6.1 2.5 Absorban- SCOI: set to optimize data resolution Abwbsa format: 5 nm/mm Wt wMh: 2.06 nm (This sets the optio bandwidth) %an rspeed: 300 nrnlm
14、in maximum Response time: 6.5-2 s JlA/EIA-455- 106 Page 5 5.2 Run a zero baseline scan, commonly referred to as “background correction,“ using the two quartz windows with oil between windows), but with no specimen installed. Mount the specimen holder such that the quartz windows are oriented normal
15、to the incoming light beam. This corrects for absorption, reflection, and scattering losses due to the test apparatus and/or vessel (quartz windows and oil, in this case). NOTE: It should also be noted that some spectrophotometers (double beam) automatically and continuously correct for the vessel a
16、bsorbance, and others (single beam) will require more frequent background correction due to equipment drift. 5.3 Mount the specimen-under-test in between the two windows so that it is neither wrinkled nor stretched. Apply sufficient oil such that both film surfaces are completely “wet“ optically aft
17、er pressing the windows lightly together, effectively “sandwiching“ the film(s)- under-test. See Figure 1 below. If air bubbles exist, apply additional oil. Keep windows and specimens clean. Fingerprints, dust particles, and other contamination add to experimental uncertainty. Film Sample Conf igura
18、tisn Clamp Pressure (uniform around perimeter) k- light Beam Direction Quartz window (Two used) Film sampie(s) (Immersed in oil, positioned normal to incident beam. ) Figure 1 TIMEIA-455- 106 Page 6 5.4 Run a spectrophotometer scan. 5.5 If only one specimen thickness is available, add another film s
19、pecimen between the windows, making sure that just enough oil is used between the film specimens to ensure good optical wetting. NOTE: The windows and film specimens shall be cleaned between every run. Use isopropyl alcohol (IPA) to clean the quartz windows, and use dry, non-Ming wipes to clean the
20、films. 5.6 Repeat steps 5.3 to 5.5 until at least 3 specimens of the same thickness have been stacked, then proceed. If multiple thicknesses are available, repeat this procedure (steps 5.3 to 5.5) for ali thicknesses of interest (but at least three), and then proceed. 5.7 Check the zero baseline for
21、 equipment drift or window degradation. Run a scan with just the quartz windows, cleaned, with a fresh supply of oil. If any value is more than +i- 0.01 A.U. at any wavelength from the zero baseline, check for damage to the windows, holder placement (with respect to the light beam), and spectrophoto
22、meter settings. If a problem exists, reptace and/or adjust and restart test, since the data are invalid. 6. CALCULATIONS OR INTERPRETATION OF RESULTS 6.1 Average Absorbance Unless otherwise requested in the Detail Specification, compute the average absorbance for each of the following three waveleng
23、th bands: 750-900 nm, 1250-1 350 nm, and 1500- 1600 nm. Also, record the maximum absorbance value and its corresponding wavelength in each ban 7 points in atl; or 5 points for the 1250-1350 and 1500-1600 ban&). 6.2 Modified Extinction Coefficient Absorbance, A, is linearly proportional to the thickn
24、ess of the fiim, and is governed by equation (i : A = kCx (1) k - molar extinction coefficient C t molar concentration where . x = fim thickness The product of the molar extinction coefficient and the molar concentration is called the “modified extinction coefficient ,“ kc, equation (2). For each Wa
25、velength band, determine the modified extinction coefficient from the slope of the line generated by a plot of absorbance versus average film thickness: A f (kcp (2) where kc - modified extinction coefficient TIA/ElA-455- 1 06 Page 7 NOTE: The plot of A (average absorbance) vs x (average thickness)
26、shall include the origin, zero absorbance and zero thickness. Thus, along with the three thicknesses measured, a te-:“l of 4 points shall be plotted, as shown in Figure 2. Fit the data to a line, using a “least squares“ regression, ensuring the line includes zero absorbance at zero thickness to dete
27、rmine the clope, kc Three plots, one for each wavelength band, shall be generated using the absorbance values calculated in 6.1, and the average film thicknesses measured in accordance with 4.2. Absorbance vs Thickness (Slope of line is kc) a 0.75 0.50 o n L O fn f 0.25 O O 50 100. 150 Thickness, pm
28、 Figure 2 Since the optical power lost through the sample coating material, in decibels, is equal to ten times the absorbance, the modified extinction coefficient can be used to predict power loss through a hypothetical thickness. For example, if kc is 0.001 (pm)- , then the optical loss through a 5
29、0 pm specimen would be 0.01 times 50, which equals 0.5 dB. 7. DOCUMENTATION 7. 1 The following information shall be reported for each sample tested: 7.1.1 Date of ?he test. 7.1.2 Film batch designation: Product name, batch number. 7.1.3 Instrument used: Manufacturers name and model number. 7.1.4 Ins
30、trument settings. 7.1.5 Film preparation method, and equipment used, 7.1.6 Thickness measurement equipment. 7.1.7 Any procedural differences from those specified herein. 7.1.0 Test results: 7.1.8.1 Average absorbance for each wavelength range (6.1). 7.1.8.2 Absorbance maximum, and respective Wavelen
31、gth, for each wavelength range (6.1). 7.1.8.3 Number of specimens tested, and their respective thicknesses, for each sample material. (4.2). 7.1.8.4 Modified extinction coefficient for each wavelength range, for each sample material. (6.2). 7.2 United States military applications require that the fo
32、llowing information also be reported for each test. For other (nonmilitary) applications, this information need not be reported but shali be available for review upon request: 7.2.1 Test personnel. 7.2.2 Brief description of test equipment, including latest calibration date. 7.2.3 Laboratory noteboo
33、k reference. 8 . SPEClFlCATION INFORMATION The following shall be specified in the Detail Specification: 8.1 8.2 8.3 Specimen thicknesses desired, 8.4 8.5 Accepreject criteria. Any procedural differences from those specified herein. Sample identification, number of samples or sampling plan. Waveleng
34、th ranges to be measured. TIA/EIA-455- 106 Page 9 APPENDIX COMPARISON BETWEEN THIS FOTP AND IEC OR CCITT REQUIREMENTS (Nonmandatory Information) X 1. INTRODUCTION One of TIAS policy objectives is to promote, whenever and wherever possible, the woridwide harmonization of fiber-optic test procedures.
35、This Appendix gives the user of this FOTP an indication of comparable measurements and test procedures (if any) that have been adopted, or are in preparation, by IEC or CCITT. This Appendix is nonmandatory and is for guidance and general information only. For further details refer to the cited refer
36、ences, plus available follow-up data io determine what changes may have been proposed since the printing of this FOTP. XI. DOCUMENTS IN PRINT x2.1 m There are no known comparable IEC documents in print. x2.2 ccm There are no known comparable CCITT documents in print. X3. DOCUMENTS IN PROGRESS x3.1 II% There are no known comparable IEC documents in progress. X3.2 CCm There are no known cornparable CCITT documents in progress. /- i
