Tutorial

Let’s start your survay of dielectric properties of various materials. The first thing you must do is to create a RiiDataFrame oject. The first trial will take a few minutes, because experimental data will be pulled down from Polyanskiy’s refractiveindex.info database and equi-spaced grid data will be obtained by interpolating the experimental data.

import riip
ri = riip.RiiDataFrame()

Catalog file not found.
Cloning Repository...
Done.
Creating catalog file...
Done.
Creating raw data file...
Done.
Updating grid data file...
Done.

You can use some helper methods for your survay.

search

search(name: str) -> DataFrame

This method searches data that contain given name of material and return a catalog for them.

ri.search("NaCl")

	book	section	page	formula	tabulated	wl_min	wl_max
id
182	NaCl		Li	1	f	0.20	30.0000
183	NaCl		Querry	0	nk	0.22	166.6667

ri.search("sodium").head(5) # upper or lower case is not significant

	book	section	page	formula	tabulated	wl_min	wl_max
id
127	NaBr		Li	1	f	0.210	34.0000
182	NaCl		Li	1	f	0.200	30.0000
183	NaCl		Querry	0	nk	0.220	166.6667
229	NaF		Li	1	f	0.150	17.0000
295	NaI		Jellison	1	f	0.436	0.6330

select

select(condition: str) -> DataFrame

This method make a query with the given condition and return a catalog. For example, if you want to find a material whose refractive index n is in a range 2.5 < n < 3 somewhere in the wavelength range 0.4μm < wl < 0.8μm:

ri.select("2.5 < n < 3 and 0.4 < wl < 0.8").head(5)

	book	section	page	formula	tabulated	wl_min	wl_max
id
23	Al	Experimental data	Mathewson	0	nk	0.495940	1.771200
118	Bi	Experimental data	Hagemann	0	nk	0.000002	6.199000
129	TlBr		Palik	1	f	0.570000	39.400000
135	C	Amorphous thin film	Larruquert	0	nk	0.019656	10.079189
137	C	Graphite	Djurisic-o	0	nk	0.030996	10.332000

show

show(ids: int | Sequence[int]) -> DataFrame

This method shows the catalog for given ids.

ri.show([23, 118])

	book	section	page	formula	tabulated	wl_min	wl_max
id
23	Al	Experimental data	Mathewson	0	nk	0.495940	1.7712
118	Bi	Experimental data	Hagemann	0	nk	0.000002	6.1990

read

read(id, as_dict=False)

This method returns the contants of a page associated with the id.

print(ri.read(23))

# this file is part of refractiveindex.info database
# refractiveindex.info database is in the public domain
# copyright and related rights waived via CC0 1.0

REFERENCES: "A. G. Mathewson and H. P. Myers. Absolute values of the optical constants of some pure metals, <a href=\"https://doi.org/10.1088/0031-8949/4/6/009\"><i>Phys. Scr.</i> <b>4</b>, 291-292 (1971)</a>"
COMMENTS: "298 K (24.85 °C)"
DATA:
  - type: tabulated nk
    data: |
        0.49594 0.77909 5.84012
        0.50606 0.81783 5.93033
        0.51660 0.85227 6.10134
        0.52759 0.89107 6.22848
        0.53906 0.94408 6.35541
        0.55104 1.00461 6.51991
        0.56356 1.06864 6.64394
        0.57667 1.14503 6.76839
        0.59040 1.21981 6.92733
        0.60480 1.30548 7.08550
        0.61992 1.40111 7.20855
        0.63582 1.50675 7.36684
        0.65255 1.62810 7.49338
        0.67018 1.77579 7.65855
        0.68880 1.94186 7.82757
        0.70848 2.13059 8.00246
        0.72932 2.33676 8.15233
        0.75142 2.57452 8.25398
        0.77490 2.87316 8.23135
        0.79990 3.03948 8.07703
        0.82656 2.93996 7.75521
        0.85506 2.52983 7.60921
        0.88560 2.13552 7.74987
        0.91840 1.81758 8.14270
        0.95372 1.57683 8.68829
        0.99187 1.41421 9.19239
        1.03320 1.31513 9.73291
        1.07812 1.24965 10.32287
        1.12713 1.22635 10.88595
        1.18080 1.22466 11.55421
        1.23984 1.25115 12.18874
        1.30510 1.29739 12.91059
        1.37760 1.34628 13.70447
        1.45864 1.42835 14.52722
        1.54980 1.50000 15.50000
        1.65312 1.58999 16.47811
        1.77120 1.75488 17.75048
SPECS:
    n_absolute: true
    wavelength_vacuum: true
    temperature: 298 K

references

references(id: int)

This method returns the REFERENCES of a page associated with the id.

ri.references(23)

A. G. Mathewson and H. P. Myers. Absolute values of the optical constants of some pure metals, Phys. Scr. 4, 291-292 (1971)

plot

plot(id: int, comp: str = "n", fmt1: str = "-", fmt2: str = "--", **kwargs)

• id: ID number

• comp: ‘n’, ‘k’ or ‘eps’

• fmt1 (Union[str, None]): Plot format for n and Re(eps), such as “-”, “–”, “:”, etc.

• fmt2 (Union[str, None]): Plot format for k and Im(eps).

This plot uses 200 data points only. If you want more fine plots, use plot method of RiiMaterial explained below.

ri.plot(23, "n")

ri.plot(23, "k")

ri.plot(23, "eps")

material

material(params: dict) -> Material

This method returns Material-class instance for given parameter dict params.

params can includes the following parameters, * ‘id’: ID number. (int) * ‘book’: book value in catalog of RiiDataFrame. (str) * ‘page’: page value in catalog of RiiDataFrame. (str) * ‘RI’: Constant refractive index. (complex) * ‘e’: Constant permittivity. (complex) * ‘bound_check’: True if bound check should be done. Defaults to True. (bool) * ‘im_factor’: A magnification factor multiplied to the imaginary part of permittivity. Defaults to 1.0. (float)

Al = ri.material({'id': 23})
type(Al)

riip.material.Material

Using the created Material object, you can get refractive index n, extinction coefficient k, and dielectric function eps, and plot them. ### Material.n

n(wl: ArrayLike) -> ArrayLike

Al.n(1.0)  # refractive index at wavelength = 1.0μm

1.3899282542977849

Material.k

k(wl: ArrayLikey) -> ArrayLike

Al.k(1.0)  # extinction coeficient at wavelength = 1.0μm

9.29612443028388

Material.eps

eps(wl: ArrayLike) -> ArrayLike

Al.eps(1.0)  # permittivity at wavelength = 1.0μm

(-84.48602887122551+25.84189200223893j)

Wavelengths wl can be a single complex value or an array of complex values.

import numpy as np
wls = np.linspace(0.5, 1.6)
Al.eps(wls)

array([ -33.67756077 +9.32237639j,  -37.37099091+10.76642941j,
        -40.48007076+12.53258237j,  -43.40382102+14.56069085j,
        -46.40772695+16.83596896j,  -49.24177749+19.32450842j,
        -51.87203854+22.05584598j,  -53.97258292+25.08305181j,
        -56.53596324+28.78875995j,  -58.88350388+32.86521087j,
        -60.71385987+37.1741283j ,  -61.57228729+41.55945809j,
        -60.12911702+46.32015037j,  -57.30534918+49.05004179j,
        -53.3025562 +47.83949057j,  -50.89837648+43.14679491j,
        -51.84632276+37.58238573j,  -54.80097964+33.65174018j,
        -59.37975454+30.91365925j,  -65.24676207+28.98346003j,
        -71.68601924+27.6368441j ,  -77.56359077+26.62565318j,
        -82.98698417+25.95615477j,  -88.58984464+25.65838341j,
        -94.49488142+25.59806765j, -100.57222728+25.6620527j ,
       -106.3896107 +25.86504049j, -111.80012917+26.22868897j,
       -117.37650002+26.73629885j, -123.56896814+27.35630896j,
       -129.97026563+28.05783746j, -135.99407702+28.81629758j,
       -141.62435872+29.63680412j, -147.25028441+30.54125595j,
       -153.19700042+31.53811566j, -159.4443053 +32.58896426j,
       -165.88659102+33.64199735j, -172.41898046+34.66687562j,
       -178.95505801+35.7002317j , -185.40696369+36.7933805j ,
       -191.7123965 +37.98898528j, -197.97226367+39.26611951j,
       -204.35066317+40.57994135j, -211.02107129+41.88287652j,
       -218.04602584+43.14590685j, -225.27973828+44.37584349j,
       -232.54532389+45.58404429j, -239.65527993+46.78308758j,
       -246.5066451 +47.9890921j , -253.186526  +49.22401988j])

Material.plot

plot(wls: np.ndarray, comp: str = "n", fmt1: str = "-", fmt2: str = "--", **kwargs)

• wls: Wavelength [μm].

• comp: ‘n’, ‘k’ or ‘eps’

• fmt1 (Union[str, None]): Plot format for n and Re(eps), such as “-”, “–”, “:”, etc.

• fmt2 (Union[str, None]): Plot format for k and Im(eps).

import matplotlib.pyplot as plt
wls = np.linspace(0.5, 1.0)
Al.plot(wls, "n")
plt.show()
Al.plot(wls, "k")
plt.show()
Al.plot(wls, "eps")
plt.show()