Optical constants

Refractive index of KTiOPO₄ (Potassium titanyl phosphate, KTP)

Kato and Takaoka 2002: n(α) 0.43–3.54 µm

Data: formula 4
Range: 0.43–3.54 µm
Temperature: 293 K
Optical axis: alpha
Licence: CC0-1.0

Biaxial crystal, axes: alpha

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.768
Extinction coefficient k: 0

Permittivity ε₁: 3.12581
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: 25.565
Chromatic dispersion dn/dλ: -0.150646 µm⁻¹

Group index n_g: 1.85652
Group velocity dispersion: 310.723 fs²/mm

Dispersion parameter D: -1695.16 ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = n − λ dn/dλ, GVD = λ³/(2πc²) d²n/dλ², D = −(λ/c) d²n/dλ². Group-velocity dispersion is given for formula data only.

Use it in Lightsmith

Load this data in Python, simulate in one more line

pip install lightsmith

import lightsmith as ls

# KTiOPO4 (Potassium titanyl phosphate, KTP): Kato and Takaoka 2002: n(α) 0.43–3.54 µm
ktiopo4 = ls.fetch_refractiveindex("main", "KTiOPO4", "Kato-α", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ktiopo4.range_nm)  # (430, 3540) nm
eps = ktiopo4.eps([633])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_86cfb56a1fb2/lightsmith"
ktiopo4 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ktiopo4.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (ktiopo4/kato-takaoka-2002).

# ... load ktiopo4 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ktiopo4)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=430, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

Materials guide Open a sphere of it in Studio Quick start Ask the community

Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.

Dispersion formula

RefractiveIndex.INFO (formula 4), λ in µm

n^{2} = 3.291 + \frac{0.0414 λ^{0.0}}{λ^{2} - {0.03978}^{1.0}} + \frac{9.35522 λ^{0.0}}{λ^{2} - {31.45571}^{1.0}}

Valid from 0.43 to 3.54 µm.

Coefficients as stored

C_i	Value
C1	3.291
C2	0.0414
C3	0.0
C4	0.03978
C5	1.0
C6	9.35522
C7	0.0
C8	31.45571
C9	1.0

Comments and conditions

n_α; 20 °C.

Conditions

temperature: 293 K
direction: alpha

References

K. Kato and E. Takaoka. Sellmeier and thermo-optic dispersion formulas for KTP. Appl. Opt. 41, 5040-5044 (2002).

doi:10.1364/ao.41.005040 Sellmeier and thermo-optic dispersion formulas for KTP, Applied Optics (2002)

Cite

Kiyoshi Kato and Eiko Takaoka. Sellmeier and thermo-optic dispersion formulas for KTP. Applied Optics, 41, 5040 (2002), doi:10.1364/ao.41.005040; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 400 wavelengths, the same grid as the API and the library

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

KTiOPO4 (Potassium titanyl phosphate, KTP), Kato and Takaoka 2002: n(α) 0.43–3.54 µm: n and k versus wavelength
λ (µm)	n
0.43	1.81028
0.432278	1.809222
0.434568	1.808181
0.43687	1.807155
0.439184	1.806146
0.441511	1.805151
0.44385	1.804172
0.446201	1.803208
0.448565	1.802258
0.450941	1.801322
0.45333	1.800401
0.455731	1.799493
0.458145	1.798598
0.460572	1.797717
0.463012	1.796848
0.465465	1.795992
0.467931	1.795149
0.47041	1.794318
0.472902	1.793499
0.475407	1.792691
0.477925	1.791896
0.480457	1.791111
0.483002	1.790338
0.485561	1.789576
0.488133	1.788824
0.490719	1.788083
0.493318	1.787352
0.495932	1.786632
0.498559	1.785922
0.5012	1.785221
0.503855	1.78453
0.506524	1.783849
0.509208	1.783177
0.511905	1.782514
0.514617	1.78186
0.517343	1.781215
0.520084	1.780578
0.522839	1.779951
0.525608	1.779331
0.528393	1.77872
0.531192	1.778117
0.534006	1.777523
0.536835	1.776935
0.539678	1.776356
0.542537	1.775785
0.545411	1.77522
0.548301	1.774663
0.551205	1.774114
0.554125	1.773571
0.557061	1.773036
0.560012	1.772507
0.562978	1.771986
0.565961	1.771471
0.568959	1.770962
0.571973	1.77046
0.575003	1.769964
0.578049	1.769475
0.581111	1.768992
0.584189	1.768514
0.587284	1.768043
0.590395	1.767578
0.593523	1.767118
0.596667	1.766664
0.599828	1.766216
0.603005	1.765773
0.6062	1.765336
0.609411	1.764904
0.612639	1.764477
0.615885	1.764056
0.619147	1.763639
0.622427	1.763228
0.625725	1.762821
0.629039	1.76242
0.632372	1.762023
0.635721	1.761631
0.639089	1.761243
0.642475	1.760861
0.645878	1.760482
0.6493	1.760108
0.652739	1.759739
0.656197	1.759374
0.659673	1.759013
0.663168	1.758656
0.666681	1.758303
0.670213	1.757955
0.673763	1.75761
0.677332	1.757269
0.68092	1.756933
0.684528	1.7566
0.688154	1.75627
0.691799	1.755945
0.695464	1.755623
0.699148	1.755305
0.702852	1.75499
0.706575	1.754679
0.710318	1.754371
0.714081	1.754067
0.717864	1.753766
0.721667	1.753468
0.72549	1.753174
0.729333	1.752882
0.733196	1.752594
0.737081	1.752309
0.740985	1.752027
0.74491	1.751748
0.748857	1.751472
0.752824	1.751199
0.756812	1.750929
0.760821	1.750661
0.764851	1.750396
0.768903	1.750135
0.772976	1.749875
0.777071	1.749619
0.781187	1.749365
0.785326	1.749114
0.789486	1.748865
0.793668	1.748619
0.797873	1.748375
0.802099	1.748134
0.806348	1.747895
0.81062	1.747658
0.814914	1.747424
0.819231	1.747192
0.823571	1.746962
0.827934	1.746735
0.83232	1.746509
0.836729	1.746286
0.841161	1.746065
0.845617	1.745846
0.850097	1.74563
0.8546	1.745415
0.859127	1.745202
0.863679	1.744991
0.868254	1.744782
0.872853	1.744575
0.877477	1.74437
0.882126	1.744166
0.886799	1.743965
0.891496	1.743765
0.896219	1.743567
0.900967	1.743371
0.90574	1.743176
0.910538	1.742983
0.915361	1.742792
0.92021	1.742603
0.925085	1.742415
0.929986	1.742228
0.934912	1.742043
0.939865	1.74186
0.944844	1.741678
0.949849	1.741497
0.954881	1.741318
0.959939	1.74114
0.965024	1.740964
0.970136	1.740789
0.975276	1.740616
0.980442	1.740443
0.985636	1.740272
0.990857	1.740103
0.996106	1.739934
1.00138	1.739767
1.00669	1.739601
1.01202	1.739436
1.01738	1.739272
1.02277	1.739109
1.02819	1.738948
1.03364	1.738787
1.03911	1.738628
1.04462	1.73847
1.05015	1.738312
1.05571	1.738156
1.06131	1.738001
1.06693	1.737846
1.07258	1.737693
1.07826	1.73754
1.08397	1.737389
1.08972	1.737238
1.09549	1.737088
1.10129	1.736939
1.10713	1.73679
1.11299	1.736643
1.11889	1.736496
1.12481	1.73635
1.13077	1.736205
1.13676	1.73606
1.14279	1.735916
1.14884	1.735773
1.15492	1.73563
1.16104	1.735488
1.16719	1.735347
1.17338	1.735206
1.17959	1.735066
1.18584	1.734927
1.19212	1.734788
1.19844	1.734649
1.20479	1.734511
1.21117	1.734374
1.21759	1.734236
1.22404	1.7341
1.23052	1.733964
1.23704	1.733828
1.24359	1.733692
1.25018	1.733557
1.2568	1.733423
1.26346	1.733288
1.27015	1.733154
1.27688	1.73302
1.28365	1.732887
1.29045	1.732754
1.29728	1.732621
1.30415	1.732488
1.31106	1.732355
1.31801	1.732223
1.32499	1.732091
1.33201	1.731959
1.33907	1.731827
1.34616	1.731695
1.35329	1.731564
1.36046	1.731432
1.36767	1.7313
1.37491	1.731169
1.38219	1.731037
1.38952	1.730906
1.39688	1.730774
1.40428	1.730643
1.41172	1.730511
1.41919	1.73038
1.42671	1.730248
1.43427	1.730116
1.44187	1.729984
1.44951	1.729852
1.45719	1.72972
1.46491	1.729587
1.47267	1.729455
1.48047	1.729322
1.48831	1.729189
1.49619	1.729055
1.50412	1.728921
1.51209	1.728787
1.5201	1.728653
1.52815	1.728519
1.53625	1.728384
1.54438	1.728248
1.55257	1.728112
1.56079	1.727976
1.56906	1.727839
1.57737	1.727702
1.58573	1.727565
1.59413	1.727427
1.60257	1.727288
1.61106	1.727149
1.61959	1.727009
1.62817	1.726868
1.6368	1.726727
1.64547	1.726586
1.65419	1.726443
1.66295	1.7263
1.67176	1.726157
1.68062	1.726012
1.68952	1.725867
1.69847	1.725721
1.70747	1.725574
1.71651	1.725427
1.7256	1.725278
1.73475	1.725129
1.74394	1.724978
1.75317	1.724827
1.76246	1.724675
1.7718	1.724522
1.78118	1.724368
1.79062	1.724213
1.80011	1.724056
1.80964	1.723899
1.81923	1.72374
1.82886	1.723581
1.83855	1.72342
1.84829	1.723258
1.85808	1.723095
1.86793	1.72293
1.87782	1.722764
1.88777	1.722597
1.89777	1.722428
1.90782	1.722258
1.91793	1.722087
1.92809	1.721914
1.9383	1.72174
1.94857	1.721564
1.95889	1.721386
1.96927	1.721207
1.9797	1.721027
1.99019	1.720844
2.00073	1.72066
2.01133	1.720474
2.02199	1.720287
2.0327	1.720097
2.04347	1.719906
2.05429	1.719713
2.06517	1.719517
2.07611	1.71932
2.08711	1.719121
2.09817	1.718919
2.10928	1.718716
2.12046	1.71851
2.13169	1.718302
2.14298	1.718092
2.15434	1.71788
2.16575	1.717665
2.17722	1.717448
2.18875	1.717228
2.20035	1.717006
2.21201	1.716781
2.22372	1.716554
2.2355	1.716323
2.24735	1.716091
2.25925	1.715855
2.27122	1.715616
2.28325	1.715375
2.29535	1.71513
2.30751	1.714883
2.31973	1.714632
2.33202	1.714378
2.34437	1.714121
2.35679	1.713861
2.36928	1.713597
2.38183	1.71333
2.39444	1.713059
2.40713	1.712785
2.41988	1.712506
2.4327	1.712225
2.44559	1.711939
2.45854	1.711649
2.47157	1.711355
2.48466	1.711057
2.49782	1.710755
2.51105	1.710449
2.52436	1.710138
2.53773	1.709823
2.55117	1.709503
2.56469	1.709178
2.57827	1.708849
2.59193	1.708514
2.60566	1.708175
2.61946	1.70783
2.63334	1.70748
2.64729	1.707125
2.66132	1.706764
2.67541	1.706398
2.68959	1.706026
2.70383	1.705648
2.71816	1.705263
2.73256	1.704873
2.74703	1.704476
2.76158	1.704073
2.77621	1.703663
2.79092	1.703246
2.80571	1.702823
2.82057	1.702392
2.83551	1.701953
2.85053	1.701508
2.86563	1.701054
2.88081	1.700593
2.89607	1.700123
2.91141	1.699645
2.92684	1.699159
2.94234	1.698663
2.95793	1.698159
2.9736	1.697646
2.98935	1.697123
3.00519	1.69659
3.02111	1.696047
3.03711	1.695495
3.0532	1.694931
3.06937	1.694357
3.08563	1.693771
3.10198	1.693174
3.11841	1.692565
3.13493	1.691945
3.15154	1.691311
3.16823	1.690665
3.18502	1.690006
3.20189	1.689333
3.21885	1.688646
3.2359	1.687944
3.25305	1.687228
3.27028	1.686496
3.2876	1.685749
3.30502	1.684985
3.32253	1.684205
3.34013	1.683407
3.35782	1.682591
3.37561	1.681757
3.39349	1.680904
3.41147	1.680031
3.42954	1.679137
3.44771	1.678223
3.46597	1.677287
3.48433	1.676328
3.50279	1.675346
3.52135	1.674339
3.54	1.673308

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

KTiOPO₄ (Potassium titanyl phosphate, KTP): all datasets

About KTiOPO4 (Potassium titanyl phosphate, KTP)

Potassium titanyl phosphate (KTiOPO₄, commonly abbreviated as KTP) is a nonlinear optical material widely used in a variety of photonic applications, including frequency doubling of laser sources, optical parametric oscillation, and electro-optic modulation. KTP exhibits a broad transparency range from approximately 350 nm to 4.5 μm. One of its noteworthy advantages is its high damage threshold, which makes it suitable for high-power laser applications. The crystal also exhibits good phase-matching conditions over an extensive range of wavelengths, making it a material of choice for tunable and multi-wavelength laser sources. It's commonly utilized in green laser pointers via frequency doubling of Nd:YAG or Nd:YVO₄ lasers, which emit at 1064 nm. Overall, KTP's combination of optical and mechanical properties make it an important material in the field of nonlinear optics.

More about KTiOPO4 (Potassium titanyl phosphate, KTP) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/KTiOPO4/nk/Kato-alpha.yml
ID: ds_86cfb56a1fb2
API: /v1/datasets/ds_86cfb56a1fb2

Plot