18/Apr/2007 for thin film calculation, added choice of material for actual thin film layers themselves, in addition to the substrate. This allows for fully dispersive calculations on the entire stack and substrate. Current materials include Ag and Al. Contact Luxpop for more materials.
10/Apr/2007 for thin film calculation, added choice of material for substrate: users now can choose between either a) inputting a fixed (n,k) for the substrate or b) specifying a material of your choice. This leads to fully dispersive calculations on the substrate and simplifies user input. Contact us for more materials.
5/Apr/2007 for thin film calculation, added two features: a) simultaneous transmissivity and reflectivity calculation; both results are now displayed at the same time b) added angular sweep feature to quantify impact of incident angle on performance
26/Mar/2007 added etalon finesse calculation. See link in "General optical"
16/Mar/2007 recent requests from various users: looking for index of refraction of 1) Teflon, 2) Phyllosilicates, 3) NH3 ammonia ice from UV to far IR, and 4) gold at cryogenic temperatures. See the "contact" page for more info.
4/Jan/2007 FEEDBACK from Ian Farrer: The "n for AlGaInAs" lattice matched to InP calculator appears to be broken.It would seem that the wavelength and composition are not being read correctly from the input page into the calculator so that the output page is incorrect... ANSWER: Thanks for pointing out the problem: the bug was such that the program always answered "NaN" instead of giving an answer for the AlGaInAs index. This has now been fixed. More feedback always welcome.
3/Jan/2007 FEEDBACK from Eric D.: I cannot find the code for certain calculations in the open source section. Where is it? ANSWER: Although the great majority are revealed, some code implementations of computation algorithms were not written by luxpop but rather were contributed by other people, and luxpop generally does not reveal the code written by other contributors unless they explicitly state that they want this. If you really want to see some unpublished code implementations of calculation algorithms, contact luxpop and you will be put in touch with the original author who will then make his/her own decision on what to release to whom.
30/Nov/2006 ADDED by request: code for index of refraction calculations of most materials on site. Luxpop generates index of refraction values using two basic methods, depending on the reference: table lookup or calculations such as Sellmeier equations, 3 point Cauchy interpolations, and so on. The code shows the great majority of index of refraction calculations. It can be found in RefractiveIndex_v1.c (or subsequent revs) in the source code section above right. This should make it easier for users to 1) get large numbers of values faster and 2) verify that Luxpop has not made any mistake. GeneralFormulae also updated, uprevved to v2.
30/Nov/2006 QUESTION from ??: What are the units for thickness in the thin film stack calculation? ANSWER: It is recommended that you use nanometres for both wavelength and thickness as this will make the calculation consistent with the rest of the site.
25/Nov/2006 ADDED: 1) layer thickness sweep on thin film stack calculation. User can now sweep thickness of a layer to calculate impact on thin film stack performance 2) Max number of layers now increased to ~15. New code build is calcx_v1.5.0 and includes files in source code section above right
25/Nov/2006 CORRECTIVE ACTION resulting from code flaw pointed out on 20/Aug of this year. One major root cause of this incident was the absence of a systemic verification procedure. As a result, all new code builds will follow a verification procedure as follows. 1) "Known-good" verification calculations will be defined and published on the site. At least some of these "known good" verification calculations will be traceable back to published or otherwise reviewed calculations such as some appearing in journals or books like Born and Wolf. Others will be based on known values such as Brewster's angle for a given material etc, or simply on variations of such calculations. 2) New code releases will be verified to ensure that results generated are consistent with the "known good" verified calculations 3) Over time, "known good" calculations will be enhanced and modified as new features are added, peer review reveals flaws (ie if someone demonstrates that they are in fact "bad"), or additional verification coverage is deemed necessary. The intent of this corrective action is to impose a more systematic review process that everyone can follow when new code builds are released. This should reduce the probability of errors such as the one on 20/Aug from re-occurring. Calcx_v1.5.0 was the first verified this way on verification runs 1 to 6: no discrepancies were found.
27/Sep/2006 ADDED: Thin film stack calculation: max allowable size of thin film stack doubled to 10 layers by demand. See below for more info and conditions.
20/Aug/2006 FEEDBACK from ??: When I cut and paste the single layer metal film from example #1 into the thin film stack model and calculate transmittance for 0 deg incidence, I get different results for the perpendicular and parallel field components and power. These polarization states are degenerate at normal incidence and should give the same field and power, what is happening? ANSWER: There was indeed a flaw in the transmissivity calculation introduced a few weeks ago (9/Jul). The transmissivity calculation did not take into account the dielectric permittivity of the substrate medium at the last step (Born and Wolf 7th ed, sec 1.6, eq'n 51) and as such led to an incorrect power result. This has now been corrected. In addition, the results page for this calculation now includes a few nomenclature comments to clarify the results and to point out the relationship between E/H fields and perp/para polarization, as per Born & Wolf. (Note that the reflectivity calculation was ok.) Source code is calcx_2006_08_20.cpp in the source code section above right, as usual. Many thanks to the anonymous reviewer for pointing this out. Any further error/bug reports will be much appreciated.
18/Aug/2006 RECENT QUESTIONS: 1) From JB: what is the index of refraction for silicon at 980nm and 50C? and does multi-crystalline vs single-crystalline matter? 2) From Mark K: I am looking for n,k properties for p-doped silicon.
9/Jul/2006 ADDED transmissivity on thin film stack model calculation, per user request. Users now have a choice between reflectivity (from 13/Dec/2005) or transmissitivity calculations. Source code is calcx_2006_06_24.cpp; link can be found in "Source code" box above right.
8/Jul/2006 QUESTIONS: 1) from Steve: looking for n,k of Cr2O3 between 2 and 10 micron wavelength b) from Ahmed: n,k of liquid methanol in the visible 3) from Shrikant: n,k for various organic pigments eg C I Pigment Red 254( DPP), C I Pigment Orange 64, C I Pigment Blue 15 etc. This will help us in experiments of calculation of particle size distribution by Laser Diffraction method.
7/Jul/2006 Finished adding all materials from David Windt list of index of refraction values ("Long list..." above right), started 7/May.
22/Jun/2006 QUESTION: I am looking for index of refraction data for Teflon. The Dupont web site shows dn/dt for Teflon AF, but does not list the wavelength. Any idea where I can get this data? Also, any idea who I could pay to measure index of refraction of liquids?
21/Jun/2006 QUESTION: I am very surprised to find some materials that have n < 1. Is it normal?Francois ANSWER: Under some circumstances where the loss is high and k is nonzero, such as in a metal or in spectral regions of high absorption (eg near absorption peaks), it is possible that n <1. This implies a phase velocity > c. However, this has no physical significance, and such a velocity cannot be measured experimentally. Moreover, a signal cannot be propagated at this speed. Ref: Born and Wolf (ver 7), section 1.3, has a discussion about this point.
13/Jun/2006: QUESTION from Professor Yuri Kamyshkov, U of Tennessee: looking for the index of refraction of the following mixture, in the UV range (we already have it in the visible). 80% volume of n-dodecane C12H26+ 20% volume of pseudocumene C9H12 (1,2,4-trimethyl-benzene)+ 1.5 g/l concentration of PPO C15H11NO (2,5-Diphenyloxazol). The total density of the liquid is 0.78 g/cc operation temperature is 12 degree C. The material is called Liquid Scintillator and it is used for detecting antineutrinos. Currently we are improving quality of the measurements and need to account accurately the effect of production of Cherenkov radiation in the liquid scintillator by fast moving charged particles.
7/Jun/2006: COMMENT from ??: I work for II VI and would like to point out that this value is for Multi Spectral Zinc Sulfide (MS ZnS), not Regular Grade Zinc Sulfide
14/May/2006 ADDED materials from G-M on the long list of index of refraction values (link "Long list..." on top right corner of this home page, under "Material"). See entry from from 7 days ago for full info.
11/May/2006: RECENT QUESTIONS: 1) from J.T.: looking for refractive index of Aqueous Glycerol solutions %wt (specifically 22%) at 1550nm 2) from Scott: index of refraction of silica at cryogenic temperatures (~4 K - 100 K) as a function of wavelength. 3) from ??: refractive index of SU8, a type of negative-tone photoresist. Interested in the range from 400--700nm the only data point found so far is: n=1.596 when wavelength=632 nm {ed. Note: no ref for this data point.}
7/May/2006: NEW RELEASE. Long list of n,k for different materials. This new addition addresses a large number of very common requests from Luxpop users: 1) More quickly provide refractive index data without having to enter one wavelength at a time (most common request in my inbox) 2) get data for always more and more substances 3) get raw data tables in easy-to-copy formats. This list is the result of meticulous work by David Windt and Luxpop is most grateful for his allowing it to be put up here. Luxpop also thanks Mark Sulkes for his help. There is so much material that only substances starting with the letters A-F have been put up for now. More will be out soon as it gets sorted out. The link ("Long list...")can be found in the "Material" box above (top right corner of this home page ) Note that wavelengths are usually in Angstroms on the "Long list."
5/Jan/2006: recent index of refraction requests: 1) Hydrochlorothiazide 2) Cerium Fluoride crystal (CeF3) 3) black-C (amorphous) and SiON at 248 and 193nm
3/Jan/2006 FEEDBACK from ??: The results for Al may be a little low: at a wavelength of 633 nm (1.96 eV), Luxpop says that the index of refraction of aluminum at room temperature is n = 1.15 +/- 0.03 and k = 6.40 +/- 0.13.However, according to CRC, @ 1.9 eV: n=1.488, k=7.821 and @ 2.0 eV: n=1.304, k=7.479 COMMENT: fabrication parameters have a considerable impact on real and imaginary values for materials such as this. All Luxpop values should be interpreted with this in mind, and references should be checked to understand the circumstances in which the material was obtained and measured. Luxpop will try to add more values for different circumstances for popular materials in the future. Thanks for the feedback. Keep sending it.
13/Dec/2005 NEW RELEASE: model of thin film stack. Full calculation of reflectivity for light incident at an arbitrary angle on up to ~5 material layers of arbitrary complex index. Click on "Thin film stack model" link in "General Optical" section above left. Source code for this release is calcx_2005_11_30.cpp. Feedback welcome.
8/Dec/2005 Recent requests for index of refraction values: 1) GaAs with different Si doping levels 2) pyrex 3) metoclopramide hydrocloride. If anyone has a good reference, please let Luxpop know.
2/Dec/2005 Added n for acetone and n-propyl alcohol (3 wavelengths in the visible), and enhanced methanol with more wavelengths
7/Oct/2005 QUESTION from JL: Can anyone advise where I can obtain information on the spectral transmisson of solvents such as acetone, methanol, isopropanol, etc., in the range of 200-300nm? I'm interested in the possibility of uv absorption in these materials in this region, particularly if the solvents degrade the container they are in.
7/Oct/2005 QUESTION from ?? about lensmaker eq'n calculation: Regarding the calculation for a given r1 and r2 to get the f of a thin-lens: you can't tell the program to let one side of the lens be flat,(r1= infinite). ANSWER: right now Luxpop dos not allow the term "inf". The practical short-term solution is to enter a very big number relative to the other parameters. Inputting values such as 1e20 for all practical purposes works as well as inputting "inf". Will keep this in mind for future enhancements. Suggestions welcome.
5/Oct/2005 QUESTION from Merian T: looking for refractive index of plexiglas(C5H8O2)
25/Sep/2005 ADDED n and other parameters for ethanol, methanol, BTBE (single lambda)
10/Sep/2005 QUESTION from Hemanth: I'm interested in knowing the complex index of refraction for ethanol and methanol liquids.
3/Sep/2005 ADDED n for toluene (single lambda, 633nm) per user request
12/July/2005 NEW RELEASE: arbitrary reflection at complex material interface released; beta test since 21/June ok. Can reach it from "Reflectance of complex index material" link at top of page. This should address questions like the 9/Apr query.
2/July/2005 FEEDBACK on May 9th question from Dr Alan Rawle, Divisional Manager Malvern Instruments Inc., ASTM E56 Committee on Nanotechnology, and Co-Chair of SubCommittee 56.02 Characterization: Refractive Index issues occur regularly in particle sizing and we have a number of presentations on our web site (http://www.malverninstruments.com) dealing with this matter. We are the manufacturer of the Zetasizer and Mastersizer products. Both contain a He-Ne laser at 632.8nm. The MS2000 has an additional light source at 466nm for the smaller particles in its range (down to 20nm). The Zetasizer relies on photon correlation spectroscopy (PCS) and does not require RI for the intensity average that is first given. RI would be required for the ill-advised conversion to volume or number.by this technique The Mastersizer (which is a generic name, by the way)requires optical properties to measure size by laser light scattering (see ISO13320-1)- typically these will be essential below 25 microns. For material such as Cu, then these are well defined by your excellent site and also from the CRC Handbook (where it just needs to be remembered that 1.96eV ~ 632.8nm. Here are the numbers for n - ik at 632.8nm: 0.246- i3.412 obtained by interpolation at 1.86 of the 1.90 and 2.00eV values given in the 71st Edition of CRC. For soluble pharmaceuticals the old method (well described by Saveyn in a recent paper) of measurement on an Abbe of solutions of the soluble pharmaceutical extrapolated to 100% solids can be used. The imaginary component needs a little more work but can be determined by a volume concentration experiment (comparison of the known volume concentration as compared to the calculated which involves Beer-Lamber + Mie Theory). The real part can also be determined by immersion fluids and the Becke Line tests - most pharmaceuticals are in the 1.4 - 1.6 range anyway, being organic. (ˇ­)
21/June/2005 BETA RELEASE New feature: Calculate the amplitude coefficients and phase shifts for linearly polarized light at an arbitrary polarization azimuth angle, incident at an arbitrary angle on a material of arbitrary real or complex index of refraction. (Assuming incident medium index =1). See at bottom of this page in "beta" section. Feedback welcome. Source code is calcx.cpp (see above).
31/May/2005 QUESTIONS 1) from satyajit: refractive index for TDI Dimer(organic particle) 2) from Izerrouken: looking for refractive index of YAG down to 250 nm
9/May/2005 COMMENT on May 4 permittivity conversion query. The calculations for permittivity seem ok: they are reversible and seem to respect the ref. However, in order to shed more light on the issue, Luxpop is releasing more of its source code for others to look at and spot potential mistakes in this or other calculations. This will also help increase response time to queries since users can right away check what Luxpop is doing behind the scenes instead of wait for an answer on the miniblog. The file is called “GeneralFormulae.c?and covers many calculations on the site. You can get to it from the “source code?section above. This should also be useful if users want to contribute such as per the 4/Sep/2004 or 16/Feb/2005 queries. The "GeneralFormulae.c" file above features calculations invoked by "calc_2005_May_4.cgi" on luxpop.com (go to "view:source" on your browser and search for it).
9/May/2005 QUESTIONS all from unknown users 1) Equipment like the zetasizer require the refractive index of copper..i dont know abt the wavelength..what do you suggest? ANSWER: the RI for copper is given on the site. As for the wavelength, the manufacturer of the zetasizer should be able to help 2) Hi, I would like to know how can I measure the variations of refresctive index in polysilicon, if I chance the concentration level of it. 3) I want to know refractive index of Ca2Nb3O10 perovskite type nanosheets.
4/May/2005 QUESTION from ?? It appears that the conversion of complex permittivity to complex RI is not working properly. I have three different equations from two different authors to calculate permittivity and none of them give the RI that I started with. ANSWER: Will look into it. All feedback welcome
4/May/2005 QUESTION from Walter Perrie: can you confirm that alpha (absorption coefficient) is in units of inverse centimeters ANSWER: Different sources quote alpha in either inverse cm or inverse mm. Luxpop respects the conventions of the source reference. However, in certain cases Luxpop does not clearly spell out the unit conventions used. For example, PMMA has an alpha in inverse mm, C28H20N2O2B2F4H2O is in inverse cm, yet Luxpop does not always specify the difference. This will be clarified in future code revs.
9/Apr/2005 QUESTIONS 1) from Iris: I am looking for the refractive index of Indium Oxide (In2O3) versus wavelength (if possible from 300-2500nm). 2) from Federico: Please add greater coverage of PMMA index of refraction to cover the entire visible range and to include complex values where appropriate
9/Apr/2005 QUESTION from ??: Please add reflection for not normal incidence
2/Apr/2005 QUESTIONS 1) from ?? I am doing a particle size analysis of the drug terbinafine HCl (C21H25N, HCl), using light scattering but I can't find its refractive index. Would you help me to determine the refractive index at wavelegths 633-1000 nm and room temperature? 2) From Carol: Do you have any information for dn/dt of birefringent materials like quartz,calcite TeO2, PbMoO4, LiNbO3? Specifically I am interested in dnextraordinary/dt and dnordinary/dt for 633 lambda in a small temperature range deviating from room temperature
26/Mar/2005 CODE MODIFICATION UPDATE: Added index of refraction of quaternary material AlGaInAs (lattice matched to InP) per 2/Mar request. Many thanks to Professor Joachim Piprek of UC Santa Barbara for his explanations and insight, and for taking the time to dig up and send supporting documentation and references. Luxpop also thanks Professor Ivo Montrosset of Politecnico di Torino for his initial recommendations and assistance. Further note: since parameters for this and other quaternary materials have different nomenclatures and naming conventions that vary from author to author and as such are quite tricky to nail down, the source code for this quaternary material computation is opened up for all to analyze. There are important comments in the source code that should be paid attention to. All error reports, feedback, comments, and code additions are welcome. Access to this and other previously released luxpop source code is newly organized and displayed in the "source code" section above.
7/Mar/2005 QUESTIONS 1) From Ryiyanal: I am doing research on producing copper aluminium oxide (CAO) as a transparent conductive oxide. Would you help me by determining the refractive index, n for copper aluminum oxide? 2) from ?? Refractive index of Salbutamol sulphate?
6/Mar/2005 CODE MODIFICATION UPDATES 1) Extended silicon refractive index coverage with several points in the millimetre-wavelength range. Thanks to Jesse Samluk of the University of Delaware for supplying refs and hyperlink 2) Single-point cerium oxide (CeO2) now installed on calculator, following up on 2/Mar and 18/Feb posts
2/Mar/2005 ANSWER from Dr. Bonse from CSIC (Spain) for 18/Feb question: for CeO2 at 589.3 nm, n=2.31 or 2.36 depending on measurement technique (ref: Shannon et Al will be incorporated into Luxpop soon). Many thanks to Dr. Bonse for helping yet again.
2/Mar/2005 QUESTION from Liyana: I would like to know the dispersion, n' of GaAs and Alas at 850nm wavelength. CLARIFICATION REQUESTED: do you mean something like an Abbe number or the actual 'instantaneous' dn/dlambda CLARIFICATION from Liyana: I was thinking of dn/dlambda ANSWER: Thank you for clarifying. Several people have asked for this recently. Will see what can be done. Stay tuned.
2/Mar/2005 QUESTION from Ivo: Looking for InGaAlAs lattice matched with InP, ideally in mid IR range; suggests Guden and Piprek paper for Luxpop
18/Feb/2005 QUESTION from ??: What is the Refractive Index of Cerium oxyde?
16/Feb/2005 QUESTION from ??: Wouldn't it be a fairly simple matter to calculate the reflectivity as a function of angle rather than only at normal incidence? ANSWER: anybody out there have a reference to the relationship? Send it over and it will be put on Luxpop.
15/Feb/2005 CODE MODIFICATION UPDATE added SF56 per Rudolf W. request
5/Feb/2005 QUESTIONS from various users: 1) a full visible spectrum IOR range for copper would be great 2) Can you help me with the refractive index of mica?3) Refractive Index of Silicon for the range of wavelengths: 10um to 2000um (2mm) would be great!
1/Feb CODE MODIFICATION UPDATE: added polystyrene (PS) at single wavelength (633 nm) along with some compression data, per Ay, Kocabas, Aydinlia, Agan ref. This should address part of Mr./Ms. Dai's question of 16/Oct/2004. Many thanks to the anonymous contributor for supplying not only the ref but also the hyperlink to the ref, thus making it easier and less time-consuming to add the new feature. In general, the more you send (links, data, code etc), the better.
21/Jan/2005 QUESTION FROM ??: Please support more material codes, and create a function that gives the index of refraction from ...nm to ...nm in steps of ...nm SHORT ANSWER: Please specify which material you are interested in and I will see what I can do. LONG ANSWER: your idea of adding incremental index lookups is great, but I think that doing so will involve changing the lex and yacc files in the parsing etc and that will be tricky for me. However, probably someone out there has a better idea, more time, or more skill to carry out this or other requests. I have just posted the Luxpop source code files for the direct entry feature so you can take a look at them; since they will not fit easily in this mini blog I have given the links to them below. Basically del.c is the lex file, dey.c is the yacc file and de.c is the associated command processing file. If you or anyone else think you have an improvement to the code to do this or any other request, please let me know and we can figure something out. For example, there are already basic functions like Rayleigh range,fsr etc, in addition to the more elaborate calls. If you have a favourite function (written in c) that you would like to see included in luxpop but you do not know lex or yacc or how to interface from the web to your code, let me know. I can take care of the interfacing and data transfer and if you send me c code I can probably do the rest. Acknowledgement for lex and yacc: I borrowed very heavily from J. R. Levine, T. Mason, and D. Brown; "lex and yacc" by O'Reilly & Associates, Inc. to write the del.l and dey.y files.
10/Jan/2005 CODE MODIFICATION UPDATE: InGaN index of refraction extension: a) expanded max wavelength coverage to 1239 nm and b) increased maximum Indium content to 25% for certain wavelengths. Many thanks to Bill Roberts from Kopin for supplying the reference.
6/Jan/2005 FOLLOW-UP QUESTION from MM: Thank you for trying to answer my question. "Penetration depth" in the radiation detection community whether it be optical or gamma-ray means that depth where the photon intensity reduces to 1/e. "Skin depth" is equivalent, but said much less often. I do know that the optical radiation does NOT fall off exponentially when penetrating doped or undoped silicon, hence the question for an empirical equation. ANSWER: OK :) . Anyone out there have suggestions for MM?
28/Dec/2004 QUESTION from MM: Do you know where I might find a theoretical or empirical formula which predicts the penetration depth of optical light as a function of wavelength into silicon? ANSWER: The term penetration depth is unclear. For undoped silicon, the field amplitude of light will decay exponentially according to the attenuation constant (k). If k is close to zero then the losses are very small and the ˇ°penetration depthˇ± will be very large. For doped silicon or for conductors, however, a more relevant concept is skin depth. Please clarify your question. http://scienceworld.wolfram.com/physics/SkinDepth.html is always a safe bet. Further input welcome.--Guillaume
20/Dec/2004 QUESTION from Irene: I need a series of values of THF and water mixtures, such as THF-30%/H2O-70% . Besides, I also hope to know the their refractive index at different temperatures from 15 degree to 50 degree.
16/Dec/2004 QUESTION from E. Innerhofer: Im looking for the nonlinear refractive index (n2) of Yb:KYW or Yb:KGW. Can you give me a hint where I best can find this value?
12/Dec/2004 QUESTION from ?: Are index of refraction values given for substrates (i.e. bulk material) or for thin films? ANSWER: Every material is different. It depends on what can be found in publications. In general Luxpop tries to specify in each calculation result what form the material is in and sometimes gives multiple answers depending on fabrication process. Recall that fabrication parameters can have a great impact on refractive index values. If you found one or more specific materials on Luxpop that is/are not clearly specified, please specify the material(s) in a follow-up question.--Guillaume
8/Dec/2004 QUESTION from Audrey K: can you please add the index of refraction of ethanol and 2-propanol
6/DEC/2004 CODE MODIFICATION UPDATE: AlGaAs update. Luxpop now implements the algorithm from the Gehrsitz et al (2000) ref which features 1) Temperature-dependent index of refraction 2) a more recent model. Luxpop would like to thank Mark Wistey of Stanford for kindly submitting several dozen (!!!) lines of advanced code he had previously written to implement the algorithm.
4/Dec/2004 FEEDBACK from Patrick Emery (France) I tried your waist calculations {ed: Gaussian Beam Propagation} and compare the results with the "abcd" method. I found exactly the same values for a positive focal length (60mm) but a different value for a negative focal length (-60mm) !! (d1 = 2000mm ; lambda = 810 nm ; waist = 250 microns) For the second case, I found the same waist (7.232microns, Luxpop gives -7.232microns) but the d2 is different (Luxpop gives -61.724 mm, I found 58.276). Do you use the "abcd" method for these calculations ? Do you have an idea to explain these differences ? ANSWER: Luxpop uses the equations derived in the classic Kogelnik and Li (K&L) "resonators" paper. K&L derived abcd then boiled it down to a few equations (eg. eq'n 63) used by Luxpop. However, by going from abcd to equations, a sign may have been dropped when solving a quadratic, leading to a possibly incorrect answer for the negative focal length case (which is rarely used). You are probably right; I will put a warning on the calculation until I further clarify the situation. Suggestions welcome.

Here is the relevant code in Luxpop:
    *w2 = (w1*f)/ sqrt( pow(d1-f,2) + pow(PI*w1*w1/lambda,2)); //eq'n 63
    fo = PI*w1*(*w2)/lambda; //eq'n 62, Kogelnik and Li
    *d2 = f + (*w2/w1)*sqrt(fabs(f*f - fo*fo));
    *wL=GaussBeamDiv(w1,d1,lambda);
    //where GaussBeamDiv simply returns:
    result= wo * sqrt(1+ pow( (lambda * z)/(PI * wo*wo),2));

2/Dec/2004 QUESTION from Teresa (Germany):I'm loking for index of refraction for a liquid scintillator. It is called PC, pseudocumene, and tha molecular formulae is C9 H12. The wave length of the ligth that is by this liquid scintillator emitted is in the range: 2.03 - 4.14 eV (300-610 nm), that is the range for the refractive index that I also need.
30/Nov/2004 FEEDBACK from ? (1) I wanted to evaluate the InAs index from In1-xGaxAsyP1-y setting x = 0.00 and your code sets y = 0.00 and the results is the InP. I know that is possible to compute directly the index of InAs, but this comment is just to evoid errors in using this section of your program. (2) Always concerning the evaluation of the index of In1-xGaxAsyP1-y I think will be very nice to have the value of the index of the composition lattice matched to InP ANSWER: I suppose if you just want InAs then the fixed ratio index section is the better choice since it has InAs, but you raise a good point; the site may be unclear. Let me think about it for a while. Ditto for second point. Suggestions welcome--Guillaume
30/NOV/2004 QUESTION from ? LED research is important for more experts and scientists,but the refractive Index of AlGaInP or GaInP for red LED is absent. The refractive Index of AlGaInN for blue LED is absent.here,I hope you can add these!
25/NOV/2004 QUESTION from ?: I need to calculate the KD*P dispersion formula for Pockles cell. Can you help me to find it?ANSWER: here is the dispersion formula used for KDP by Luxpop (absolute indices) no = sqrt(2.260476 + 0.01011279/(lambda*lambda - (1/77.26552)) + 0.03249268/(0.0025 - (1/lambda*lambda)) ); ne = sqrt(2.133831 + 0.008653247/(lambda*lambda-(1/81.34538)) + 0.008069838/(0.0025 - 1/(lambda*lambda)) ); {Ref: Zernicke} . Valid wavelength range unspecified; Lambda in microns; if that is not what you want pls clarify request--Guillaume
23/NOV/2004 CODE MODIFICATION UPDATE 1) LiF data now available down to below 118 nm, in response to Nov 12 request. Many thanks to Dr. Bonse for digging up data and reference 2) Corrected minor typo in LiF index of refraction output in 158-457nm range. Old vesion incorrectly stated 'BaF2' instead of 'LiF' (although it did give the correct value for LiF). This has been corrected. Any reports of bugs or inaccuracies would be most appreciated -- Guillaume
23/NOV/2004 QUESTION from Matthew: index of refraction of SbKCS (bialkali photocathode)?
16/NOV/2004 QUESTION from ? index of refraction of LBO (lithium triborate)?
15/Nov/2004 QUESTION from ? index of refraction for NaOH ?
12/NOV/2004 QUESTION from ? I would like the index of refraction for 118nm in LiF
7/Nov ANSWER from Dr. J. Bonse (Spain) to Nov 1 question: If "lucite" is the same as "PMMA" and "acrylic" (as stated on the goodfellow link) http://www.goodfellow.com/csp/active/static/A/Polymethylmethacrylate.HTML then the index of refraction is on Luxpop (~1.495) Alternatively in the attached PDF which I found with Google at the following webpage http://www.rpi.edu/~schubert/Educational%20resources/
1/Nov/2004 QUESTION from Seth (USA): I am working on a PIV experiment and need to know the index of refraction of lucite (plexiglass) at a wavelength of 532nm and at room temperature.
28/Oct/2004 QUESTION from Evanice (Brazil): I've a Mastersizer to measure particle size. I need to mesure process' anthraquinone (C14H8O2) and don't have the refractive index. Do they know the anthraquinone IR? Can they help me?
27/Oct/2004 QUESTION from Lawrence: I am looking for material or substance that is clear in a normally lighted room but refracts or disperses in the 640nm to 680nm range under the same room light. Does a stable material exist?
26/Oct/2004 QUESTION from ? I wish Luxpop could calculate the index of AlGaAs up to 12000 nm !
25/Oct/2004 QUESTION from King (China): I don't know if you could tell me some information about the factory and company of GaAs or Heavily doped silicon. ANSWER: I have already asked for a clarification and am still waiting for a answer. Maybe s/he is asking for a supplier in China.--Guillaume
22/Oct/2004 QUESTION from Nurit M. (Mexico): Can you provide the refractive index of Toluene (at 18deg C and 4 deg C). I'm trying to do a Static light scattering experiment and I need this value for the standard.
21/Oct/2004 QUESTION from Jon G: Can you add dispersion as well as the index of refraction. For instance, I'd like to know the difference in the index of refraction between 590 nm and 600 nm. ANSWER: The original Luxpop source code I wrote (for the index of refraction pulldown menu ) tries to be very rigorous and as such may be inflexible by design. For example, what if the published uncertainty in the index at 590 nm is +/- 1 percent but at 600 nm it is +/-2 percent? What if one reference covers 590 but another ref. with different methodology covers 600 nm? I prefer giving users the raw data straight from the refs and letting them do as they see fit. However, I have had many people send requests such as this one for more advanced calculations and I have begun to address these and other issues in the "direct entry" input box on the luxpop home page which allows for more creativity (I would like the pulldown menu to remain more rigourous). Nonetheless, before I go any further I would appreciate input from other luxpop users. All suggestions welcome. Also, if anybody has programming skill and would like to help add features, that would also be appreciated.--Guillaume
16/Oct/2004 QUESTION from Dai: I'd like to know refractive index of polystyrene film at wavelength of 633 nm, 532 nm and 473 nm
8/Oct/2004 QUESTION from ? Is it possible to measure the linear refractive index of a dye solution from the reflectance values. The reflectance of the dye solution is measured in % using UV-VIS spectrophotometer (i.e. from the wavelength Vs reflectance graph).
8/Oct/2004 REQUEST for clarification: Someone asked for "figure of merit". Please clarify what you mean since many parameters have figures of merit associated with them -- Guillaume.
7/Oct/2004 ANSWER from Dr. Hans Sigg (Switzerland) for Carolin's Sep 15 question:for (T-dependent) below bandgap refractive index of AlxGa1-xAs, we suggest to use the more recent data published by S. Gehrsitz et.al. in Journ. of Appl. Phys. 87, 7825 (2000). Exel sheets fittings, based on the above determined parameters, can be provided on request.
7/Oct/2004 QUESTION from Kim (USA) : Does anyone have data for the temperature-dependent index of InGaAsP?
5/Oct/2004 QUESTION from Roy: are any of these calculations available for the HP49? ANSWER: right now Luxpop code is only in C. If anyone has HP49 code, please let me know and I will post it on the site-Guillaume
30/Sep/2004 QUESTION from ?: Is there any way to find the index of refraction for [copper(I) (MIBI)4] [BF4]
22/Sep/2004 QUESTION from Armel (France): Does anyone know how to calculate the absorption coefficient of a bulk crystal by taking account the non parallelism of the faces?
15/Sep/2004 QUESTION from Alejandro (Argentina): Need nonlinear indices of refraction (or Kerr coefficients), specifically for calcite (in the visible)
15/Sep/2004 QUESTION from Carolin: Need n for AlAs and In(1-x)Ga(x)As at various temperatures
9/Sep/2004 FEATURE REQUEST from Masood (Spain): Do you have a similar software (similar to PPLN OPO) for calculations of PPKTP OPO? ANSWER: I may have to retool parts of the site and calculations to do so, which could be tricky since I hardwired in some values, but if a few more people ask for it, I can put it in. Even better, if you write a routine (in C) and send it to me, I can incorporate it on the site. Contact me for more details on coding--Guillaume.
9/Sep/2004 CLARIFICATION REQUESTED from whoever submitted the following: "for w1=2500um,755nm,f=36mm olso predicts d2=34.4." Please specify d1 so that calculations can be verified -- Guillaume
8/Sep/2004 QUESTION from Weiqiang (China): Looking for a Kerr nonlinear material, whose refractive index changes with light intensity, n(I)=n_0+n_2 I, with n_0=2.34.
7/Sep/2004 QUESTION from ? Looking for n,k of liquid Cu
25/Aug/2004 QUESTIONS From Dr. Joern Bonse (Spain):
a) looking for n of liquid InP and liquid In @ 800nm and 514 nm
b) looking for conversion factors from esu absorption to n,k 24/Aug/2004 ANSWER From Dr. Joern Bonse: References for doped Si
(1) G.E. Jellison et al. "Optical Properties of heavily doped silicon between 1.5 and 4.5 eV" Phys. Rev. Lett. Vol. 46 (1981), No. 21, pp. 1414
(2) G.E. Jellsion et al. "Optical functions of ion-implanted, laser-annealed, heavily doped silicon", Phys. Rev. B, Vol. 52 (1995), No. 20, pp. 14607
(3) P. E. Schmid, "Optical absorption in heavily doped silicon", Phys. Rev. B, Vol. 23 (1981) , No. 10, pp. 5531
5/July/2004 QUESTION from Edwin (Singapore): index of (AlxGa1-x)yInyP
1/June/2004 QUESTIONS from various users:
* n,k for barite and bentonite
* n vs doping and purity level of Si and Ge
* n for lecithin
Luxpop would like to thank Professor Paul Forster of HKUST for the (excellent) idea of putting up a help wanted blog on the luxpop main page to facilitate feedback and discussions.