Giant birefringence

When values of birefringence are very high, the property is termed giant birefringence which more generically is called giant optical anisotropy. Values for giant birefringence exceed 0.3. Much bigger numbers (over 2.0) are termed "colossal birefringence" which are achieved using nanostructures.

Some oxides, for example borate or iodate can have high birefringence. Also compounds containing C=O bonds have higher levels. These include oxalates, squarates and cyanurates. One trade-off is with band gap. If the band gap is small, then the material is not transparent to visible light, but can be transparent for infrared. Chalgogenides may have high birefringence, but only in the infrared. Halide perovskites such as CsPbBrxCl3−x have fairly high birefringence that varies significantly in the optical spectrum.

Polar organic π-conjugated molecules can have a strong response to electric fields and also form flat molecules that can stack to form anisotropic crystals with high birefringence.

Some transition metal oxyhalides: MoOCl4, WOCl4, have birefringence in the giant category and MoO2Br2, WOBr4, NbOBr2, and NbOI2 are predicted to have birefringence over 0.6 at 1065 nm.

Applications Applications of materials with high birefringence include beam splitters, waveplates, optical circulators, and in some nonlinear optics systems.

List

substanceformulabirefringenceband gap eVcommentreferencecopper indium thiophosphateCuInP2S60.3@647 nm 0.5@280 nm2.8pyroelectric4-aminopyridinium difluoroiodate(C5N2H7)IO2F20.30 @ 550 nm4.06H2biim = 2,2′-biimidazole; 2,2′-biimidazolium bromide tribromogermanate(II)(H4biimBr)GeBr30.302@546bis(1,10-phenanthrolin-1-ium) hexabromotellurate(C12H9N2)2TeBr60.31@546 nmisoquinolinium-3-carboxylic acid chloride[C10H8NO2]Cl0.31@550 nmRb2Sn2F5Cl0.31@532 nmmelaminium methylsulfonate hdyrate(C3N6H7)SO3CH3·H2O0.31@546UV edge 233 nmdipotassium trithiocyanurate sesqihydrateK2HC3N3S3·1.5H2O0.31@550 nmpotassium 3-pyridinesulfonateK(3-C5H4NSO3)[email protected] edge 275 nmguanidinium hydrogen squarateC(NH2)3(HC4O4)0.313@546 nmNbSe2I20.3132,7-diazapyrene:1,2,4,5-tetrafluoro-3,6-diiodobenzene0.316@546 nm3.00blue edge 414 nmLiBF2C2O40.317@546 nmCN4H7)[email protected] nmUV edge 336 nmbarium cyanurateBa3(C3N3O3)20.32@800 nmpentazinc dicyanurate tetrahydroxideZn5(OH)4(C3N3O3)20.32@400 nmmagnesium tetrazinc dicyanurate tetrahydroxideMgZn4(OH)4(C3N3O3)20.32@400 nmpyridinium antimony oxalate difluoride hydrate[C(NH2)3]Sb(C2O4)F2·H2O0.323@546 nmCs2Sb2(C2O4)2-F4·H2O0.325@546 nm3-bromoquinolinium bromideC9H7NBrBr0.328@546 nmpotassium cadmium tricyanateK[Cd(NCO)3]0.329@546 nmUV edge 228 nmmelaminium chloride hemihydrateβ-(C3H7N6)2Cl2·H2O0.33@550 nmisoquinolinium-3-carboxylic acid nitrate[C10H8NO2]NO30.33@550 nmmethylguanidine nitrite[C2N3H8]NO20.331@546magnesium pyridine dicarboxylate octahydrate[Mg(H2O)6][(C7H4NO4)·H2O]20.34@546zinc disulfosalicylate octahydrate(C7H5O6S)2Zn(H2O)6·2H2O0.34@546melaminium sulfamateC3N6H7SO3NH20.340@546 nmUV edge 206 nm1,3-diazapyrene:1,2,4,5-tetrafluoro-3,6-diiodobenzene 0.340@546 nmisoquinolinium-1-carboxylic acid chlorideC10H10ClNO30.345@550 nmlithium 3-pyridinesulfonate0.345@546 nm(C2N5H8)3(H2C3N3S3)(HC3N3S3)·H2O0.347@550 nmscandium diiodate nitrateSc(IO3)2(NO3)0.348 at 546 nmpotassium indium tetra(iso-cyamelurate) octadecahydrateK0.5In0.5(H2C6N7O3)2·9H2O0.35@1064 nm4.05calcium squarateCaC4O40.35@1064tristrontium dicyanurateβ-Sr3(C3N3O3)0.35Hg4InS2Cl50.35@546 nm3.10protonated 3,5-dipicolinic acid iodateC7H4NO4(IO3)0.35@546 nm4.12SHG 3.6 × KDPRbHg5Br110.35@546 nm3.73potassium indium tetraiso-cyamelurate : octadecahydrateK0.5In0.5(H2C6N7O3)2·9H2O0.35@1064 nm4.05potassium tetraiodatoiodate(III) iodate(V)K2[IIII(IVO3)4]IVO30.358@543 nmSHG 21.6 × KDP at 1.064 μm; UV edge 370 nm4-cyanopyridinium mercury trichloride(C6H5N2)HgCl30.36 at 546 nmSHG 3.04 × KDP at 1.064 μmisoquinolinium-1-carboxylic acid bromideC10H8BrNO20.36@550 nmsodium tricyanomethanideNaC(CN)30.36@550 nm3.88triclinic; density 1.526cerium difluoride sulfateCeF2(SO4)0.361lithium nitrate monohydrate : 4-hydroxypyridine0.362@546 nmCdCl2(4-Aminopyridine)20.368 @ 546 nm4.26SHG 5 × KDPNa4Ba3(S2)4S30.37 at 1064 nm1,4-dimethylpiperazinium cadmium trithiocyanate(C6N2H15)Cd(SCN)30.37@550stable be;ow 519Kmelaminium tetrafluoroborate hydrate(C3N6H7)BF4·H2O0.37@546UV edge 244 nmZn(C6H4NO2)2·4H2O0.37@550UV edge 274 nmguanidinium hydrogen oxalate hydrate[C(NH2)3]HC2O4·H2O0.371@532 nmurea nitrateC(OH)(NH2)2NO30.372@546 nmmagnesium nitrate hexahydrate:4-hydroxypyridine[Mg(NO3)2·6H2O]·(4HP)20.376@532 nm4-aminopyridinium zinc hydrogenphosphite dichloride(C5H7N2)[Zn(H2PO3)Cl2]0.378@546 nmspace group Pccntrifluoromethyl(melamine sulfonate)C3N6H7SO3CF30.38@532 nmmelaminium fluoride hydrate(C3H7N6)F·H2O0.38@550 nmammonium antimony oxalate difluoride hydrateNH4Sb(C2O4)F2·H2O0.381@546cadmium diiodide:nicotinic acid 1:2Cd(C6H5NO2)2I20.388@550 nm3.94UV edge 284 nmAgHg3I3.2Cl1.8(SO4)0.39@546 nmSHG 11.8 × KH2PO4@ 1064 nm(C7H10N)3Bi2I9·I20.39@589 nmCs2Pb4Br100.392 @ 550 nm4,9-diazapyrene:1,3,5-trifluoro-2,4,[email protected] edge 425 nmsodium 5-hydroxy-2-pyridinecarboxylate hemihydrateNa2(C6H4NO3)2·H2O0.394@546SHG 6.2 × KDP; UV cutoff 282 nmbis(3-bromoquinolinium) hexafluorosilicate(C9H7BrN)2SiF60.398@550 nmRbNH4(H2C3N3O3)2·2H2O0.40 @ 1064 nm5.24diantimony difluoride bis(pyridine-2,5-dicarboxylate) dihydrate(C7H3NO4)2Sb2F2·2H2O0.40@550 nmbis(2-amino-5-nitropyridine)zinc dichloride(C5H5N3O2)2ZnCl20.40 @514 nm2.9NLO χ(3) = 4.442 × 10–9 esu; transparent 415–1400 nm; stable < 260°;rubidium 2-amino-4,6-dimercapto-S-triazine hemihydrateRb2(H2C3N4S2)2•H2O0.400@546UV edge 318 nm3-bromoquinolinium nitrateC9H7NBrNO30.401 @546 nmdipotasium hydrogen trithiocyanate hemihydrateK4(HC3N3S3)2·H2O0.402 @550 nmbiuret:cyanuric acid:water[H5C2N3O2][H3C3N3O3]·0.43H2O0.403@546 nmUV edge 208 nm(C2N5H8)(H2C3N3S3)·H2O0.403@550 nmK1.03(NH4)0.97(I5O12)(IO3)0.405 @546 nmSHG 19.5 × KDP @1064 nmLCHCY hydroisocyanurateLi2Ca(H2C3N3O3)4·6H2O0.407@800 nm4,9-diazapyrene:1,2,4,[email protected] edge 471 nmNa2Sn2F5I0.408@546Space group P21/cisoquinolinium-1-carboxylic acid bromide waterC10H8BrNO2·H2O0.41@550 nm1,3-diazapyrene:1,3,5-trifluoro-2,4,[email protected] edge 411 nmguanylurea formate[C2N4H7O]COOH0.413@546 nmammonium 2-amino-4,6-dimercapto-S-triazine hemihydrate(NH4)2(H2C3N4S2)2•H2O0.413@546 nm3.65UV edge 313 nm; Space group P21/n (birefrince could be as high as 0.510)potassium 2-amino-4,6-dimercapto-S-triazine hemihydrateK2(H2C3N4S2)2•H2O0.416@546 nmUV edge 317 nm4, 5-dichocyanimidazoleC5N4H20.417@546 nmguanidinium dihydrogen cyanurateC(NH2)3(H2C3N3O3)0.419@400 nmUV cutoff 238 nmmelamine(C6N10H8)Pb2Br60.42 at 550 nmbenzoguanaminium chloride hydrate(C9H10N5)Cl·H2O,0.42 at 550 nmcaesium 2-amino-4,6-dimercapto-S-triazine hemihydrateCs2(H2C3N4S2)2•H2O0.421@546 nmUV edge 317 nmpyrazine:oxalic acid(C4N2H4)(H2C2O4)0.422 at 550 nmguanidinium molybdenyl iodateC(NH2)2MoO3IO30.426@546 nm3.33(NH4)2(I5O12)(IO3)0.431 @546 nmSHG 16 × KDP @1064 nmmelaminium tetrafluoroborate(C3N6H7)BF40.44@546 nmmelaminium tetrafluorohydroxytriborate[C3N6H7]2[B3O3F4(OH)]0.440@546UV edge 240 nmmagnesium pyridine dicarboxylatedihydrateMg(C7H3NO4)(H2O)20.440@5464-hydroxypyridine:4-hydroxypyridinium 3-pyridinesulfonate[(4-HP)(4-H2P)][3-pySO3]0.443 @546 nmHgI2HgII(Te2O4)2(HPO4)20.444 @546 nmtripotassium cyamelurate dihydrateK3C6N7O3·2H2O0.446@1064 nmpotassium terephthalateK2C8H4O40.45@546 nmstable to 580°Cnicotinamide sulfamate(C6H7N2O)(NH2SO3)0.452@535 nmUV edge 274 nm[H2C6N7(NH2)3]SO4·2H2O0.46@5502,7-diazapyrene:1,3,5-trifluoro-2,4,6-triiodobenzene0.464@546 nm2.89blue edge 429 nmAl4(P2S6)3 0.47 @ 2050 nm2-bromo-pyridinium-4-boronic acid nitrate[HPyBrB(OH)2]·(NO3)0.477@546 nmbis(4-hydroxypyridine)zinc sulfate monohydrate(C5H5NO)2ZnSO4·H2O0.48@546 nmbis(4-hydroxypyridine)zinc chloride(p-C5H5NO)2ZnCl20.482@546 nmdisodium (deprotonated 5-hydroxy-2-pyridinecarboxylate) hydrateNa2(C6H3NO3)·H2O0.487@546 nmUV edge 321 nm; SHG 14.0 × KDP3,5-pyridinedicarboxylic acid0.49@546 nmbenzoguanaminium bromide(C9H10N5)Br0.49@550 nmphenyl thiourea mercury dichloride(C7H8N2S)[email protected] edge 328 nmbis-(3-cyanoquinolinium)hexachlorostannate(C10H9N2O)2SnCl60.50 at 550nmAmidinothiourea tetrafluoroborate(C2N4H7S)BF40.500 at 546 nm4-cyanopyridnium hexafluorosilicate(C6H5N2)2SiF60.505@546 nm4-aminopyridinium barbiturate[C5H7N2]+[C4H3N2O3]−0.507 at 546 nm9-acridiniumcarboxylic acid bromideC14H10BrNO20.507 at 550 nmdipotassium cadmium tetracyanateK2[Cd(NCO)4]0.511@546 nmUV edge 229 nmsodium hydrogen squarate hydrateNaHC4O4·H2O0.52 at 1064 nmSr4(VO4)2S30.52@550 nmHgB2S40.52 at 1064 nmtricaesium tricyanomelaminate hydrateCs3C6N9•H2O0.52@550 nmlithium nitrate monohydrate : 4-hydroxypyridine 1:20.522@546 nmdipotassium mercuric tetracyanateK2[Hg(NCO)4]0.524@546UV edge 253 nmPyrazinamide iodine [email protected](VI) pyrotellurite hydrateMo(H2O)Te2O70.528@546 nmUV edge 366 nm; SHG 5.4 × KDPBa2La2Sb4S10(S2)0.53 at 1064 nm1.862-chloro-pyridinium-4-boronic acid nitrate[HPyClB(OH)2]·(NO3)0.533@546 nmsodium terephthalateNa2C8H4O40.54@546 nmstable to 580°CHg4(Te2O5)(SO4)0.542@546 nmcaesium [4,6-Bis(cyanoamino)-1,3,5-triazin-2-yl]iminomethylideneazanideCsH2C6N9⋅H2O0.55@550 nmbarium dithioselenotelluriteBaTeSeS20.55@550 nmOptical edge 500-25,000 nm6-iodoquinazolinium nitrateC8H6IN3O40.55@550 nmaminoguanidine trithiocyanurate(CH7N4)(H2C3N3S3)[email protected] at 650 nmformamidinium hydrogensquarate(CH5N2)+(HC4O4)−0.568@546 nm3.44benzoguanaminium tetrafluoroborate hydrate(C9H10N5)BF4·H2O0.57 at 550 nmCs2S6 0.58@1064 nmtrithiocyanurateCs2Mg(H2C3N3S3)4·8H2O0.58@800 nmUV cutoff 374 nmZrTe50.58 @ 942 nm2,2'-bipyrdinium hexafluorosilicate(C10H10N2)SiF60.583@546bis[dimethylammonium] dichlorohypoiodite chloride[HDMA]2[ICl2]·Cl0.585@546 nm4-hydroxypyridinium nitrate(C5H6ON)+(NO3)−0.593 at 546 nmSHG 9.55 × KDP; space group P21/ccadmium dicyanurate octahydrateCd(H2C6N7O3)2·8H2O0.60 @ 550 nmRb3[C6N7(NCN)3]·3H2O>0.60 @ 546SHG 9×KDPCs3[C6N7(NCN)3]·3H2O>0.60 @ 546SHG 9×KDPdiberyllium dihydroxide pyridine-2,5-carboxylate dihydrate[Be2(μ-OH)2(C7H3NO4)(H2O)]·[email protected] edge 261 nmtripotassium hydronium tetrathiocyanurate tetrahydrateK3(H2C3N3S3)4(H3O)·4H2O0.604@546 nmmelem phosphateC6N7(NH2)3·H3PO40.609@1064SHG × 8.9 KDP4, 5-dichocyanimidazole hydrateC5N4H2·H2O0.618@546 nmstrontium thiocyanurate undecahydrateSr(H2C3N3S3)2·11H2O0.627@546 nm4-dimethylaminopyridinium 4,5-dicyanoimidazolide monohydrate[(C7N2H11)+(C5N4H)−]·H2O0.629@546 nm3.792,5,8-triamino-s-heptazine 2,4-guanidino-6-amino-1,3,5-triazine lead nonaiodide(C6N10H6)2(C5N10H10)2PbI90.64@546 nm3.38trigonal; UV edge 367 nmBa2HgTe50.643@2090 nm1.284-aminopyridinium dichlorohypoiodite[H-4AP][ICl2]0.647@546 nmmercury hexathiodiphosphateHg2P2S60.65@546 nm, 0.50 @ 1064 nm,