1、Designation: E 1653 94 (Reapproved 2004)Standard Guide forSpecifying Dynamic Characteristics of Optical RadiationTransmitting Fiber Waveguides1This standard is issued under the fixed designation E 1653; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the key parameters that determine thedynamic performance of an opti
3、cal radiation transmitting fiberwaveguide (see Note 1). For the purpose of this guide, opticalradiation is electromagnetic radiation of wavelengths fromabout 200 to about 5000 nm (correspondingly, frequencies of50 000 cm1to 2000 cm1, and photon energies of 6 eV to 0.25eV).NOTE 1Typical designations
4、of radiation transmitting fiberwaveguides include optical waveguide, fiber-optic, fiber-optic waveguide,and fiber-optic radiation guide.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to es
5、tablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 131 Terminology Relating to Molecular Spectroscopy3. Terminology3.1 Definition of Terms and SymbolsFor Definitions ofterms and symbols
6、, refer to Terminology E 131.4. Significance and Use4.1 Many characteristics of a fiber-optic waveguide affectthe dynamic performance. Quantitative values of certain keyparameters (characteristics) need to be known, a priori,inorder to predict or evaluate the dynamic performance of awaveguide for sp
7、ecific conditions of use. This guide identifiesthese key parameters and provides information on their signifi-cance and how they affect performance. However, this guidedoes not describe how the needed quantitative information is tobe obtained. Manufacturers of fiber-optic waveguides can usethis guid
8、e for characterizing their products suitably for userswho are concerned with dynamic performance. Users offiber-optic waveguides can use this guide to determine thattheir waveguides are adequately characterized for their in-tended application.5. Key Dynamic Characteristics5.1 Dynamic characteristics
9、 and dynamic performance, forthe purposes of this guide, have to do with the time- orfrequency-domain response of a fiber-optic waveguide topulsed or sinusoidally modulated optical radiation. Fig. 1 andFig. 2 show hypothetical outputs of an optical fiber to pulsedand sinusoidally modulated radiation
10、 inputs. (Either the time-or the frequency-domain can be used to characterize thetemporal features of a fiber-optic waveguide, because the twoare related through the Fourier transform.) It is this response, asit is affected by launch condition, input radiant flux, wave-length, bend radii, temperatur
11、e, and spatial position across theface of a fiber-optic waveguide, that is the concern of thisguide.5.2 Ideal Fiber-OpticFeatures that would be possessed byan ideal fiber-optic waveguide provide a basis for discussingthe key parameters that determine the dynamic aspects of afiber-optic waveguide. An
12、 ideal fiber-optic radiation guidewould have the following features.5.2.1 Alarge numerical aperture, such that noncollimated orpoorly collimated radiation sources (for example, arc lamps)could be coupled to it effectively.5.2.2 Wide transmissive (spectral) bandwidth, within therange from 200 to 5000
13、 nm, so that experiments requiringultraviolet (UV), visible, and IR radiation may be performedwith the minimum change in radiation guides.5.2.3 Wide temporal bandwidth (gigahertz; picosecond tofemtosecond), so that time resolution would not be compro-mised, and that high data-transfer would be possi
14、ble.1This guide is under the jurisdiction of ASTM Committee E13 on MolecularSpectroscopy and is the direct responsibility of Subcommittee E13.09 on FiberOptics in Molecular Spectroscopy.Current edition approved Nov. 1, 2004. Published January 2005. Originallyapproved in 1994. Last previous edition a
15、pproved in 1999 as E 165394 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM Internatio
16、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2.4 Known temporal response (although not necessarilyconstant) across the spectral bandwidth, so that a researchercould determine how using a fiber-optic waveguide mightcompromise particular experiments.5.3 Ke
17、y ParametersA great many parameters must beknown, ultimately, to use fiber-optic radiation guides mosteffectively. The following are seven of the key parameters thatdetermine the dynamic aspects of a fiber-optic radiation guide.FIG. 1 Output of an Optical Fiber to a Radiation Input PulseFIG. 2 Outpu
18、t of an Optical Fiber to a Sinusoidal Waveform Radiation InputE 1653 94 (2004)25.3.1 The Diameter of the Fiber-OpticThis should beincluded in all reports.5.3.2 The Length of the Fiber Optic from Which All ResultsAre CompiledIt is important that the guide be long enough toensure that the system attai
19、ns equilibrium numerical aperture.NOTE 2It is recommended that a fiber-optic cable be at least 5 m longfor all measurements.5.3.3 The peak-power handling capability of a fiber-opticradiation guide are critical for several reasons: possible de-struction of the fiber-optic by high-photon flux (namely,
20、melting or ablation of the fibers core material and surroundingcladding); non-linear effects (for example, second harmonicgeneration, and overloading problems); and luminescencebackgrounds generated from low levels of impurities. It isespecially important to determine the temporal bandwidth as afunc
21、tion of incident radiation flux at the input of the fiber-opticradiation guide.5.3.4 The Wavelength-Dependent Temporal BandwidthItis important to determine a priori how a fiber-optic radiationguide will suffice for a particular experiment. For example, fora study of processes that occur on a picosec
22、ond time scale, theradiation guide must have sufficient bandwidth. If the inputpulse (see Fig. 1) or the sinusoidal waveform (see Fig. 2) arebroadened too much or demodulated significantly, then therequired time resolution will be lost and the study will fail.NOTE 3This parameter is closely related
23、to the “spectral dispersion”commonly specified in the telecommunications field.5.3.5 The Effects of Launch Conditions on the Temporal andSpectral BandwidthsThese must be known because, formany possible reasons, the input to the fiber may not be atexactly the numerical aperture. It would be important
24、 to know,for example, what a 620 % change in the launching numericalaperture would have on the temporal and spectral bandwidths.5.3.6 The Temperature- and the Bend-Stabilities of theFiber-Optic Radiation GuideIn many circumstances (forexample, field analyses), it is difficult to control temperaturea
25、nd fiber orientation (for example, in a well hole, or coiled ona laser table), and it is therefore necessary to know what effectthese parameters have on the temporal and spectral band-widths.5.3.7 The Temporal and Spectral Characteristics of a Fiber-Optic Radiation Guide as a Function of Position Ac
26、ross theFace of the FiberThis is especially important for imagingtechniques or methods that require that the spatial profileremain homogeneous, or at least known.5.4 Reporting Key ParametersQuantitative values of thekey parameters should be provided in graphical form forconvenience of access.6. Repo
27、rt6.1 In addition to reporting values of the relevant keyparameters of an experiment, results should be reported withrespect to the input radiation source. For example, temporaldistortion should be reported as the ratio for the full-width-at-half-maxima (FWHM) for the radiation pulse after and befor
28、epassing through the fiber-optic guide (FWHMintrinsic/FWHMfiber).Also, specify the intrinsic FWHM of the radiationsource, and the length and diameter of the fiber-optic radiationguide.7. Keywords7.1 bend characteristics; dynamic characteristics; fiber op-tics; optical fibers; peak powerASTM Internat
29、ional takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely the
30、ir own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should
31、be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standar
32、ds, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E 1653 94 (2004)3
