BK4 - GOST Rus

Diagram n (λ)

n calculation

Analogue search

Main parameters
n_d = 1.530278 n_e = 1.532369	V_d = 60.48 V_e = 60.22	n_F - n_C = 0.008767 n_F' - n_C' = 0.008840

Type: Resnik
Spectral range: 0.36501 - 2.6 mkm.
C1 = 0.028 C2 = 1.52744 C3 = 0.0160545 C4 = -0.00972822 C5 = -0.001107 C6 = -0.000430015 C7 = 0.000109251 C8 = 0 C9 = 0 C10 = 0 C11 = 0

Refraction index
n _2.3254	1.504409
n _1.9701	1.509326
n _1.5296	1.514495
n _1.06	1.519778
n _t	1.520378
n _s	1.522865
n _r	1.526083
n _C	1.527606
n _C'	1.528032
n _0.6328	1.528430
n _D	1.530200
n _d	1.530278
n _e	1.532369
n _F	1.536374
n _F'	1.536872
n _g	1.541127
n _h	1.545069
n _i	1.551794
n _0.3341	-----
n _0.3126	-----
n _0.2967	-----
n _0.2804	-----
n _0.2483	-----

Relative partial dispertion
P_C,t	0.8244
P_C,A'	0.3487
P_d,C	0.3047
P_e,C	0.5432
P_g,d	1.2374
P_g,F	0.5421
P_h,g	0.4496
P_i,g	1.2166
P_C',t	0.8729
P_e,C'	0.4946
P_F',e	0.5136
P_i,F'	1.7018

Density: 2.76 g/cm³
Poisson coef.: 0.226
Rigidity: 286.5 Pa*10⁸
Young module: 702.7 Pa*10⁸
Optical stress coef.: 2.8 1/Pa*10¹²
Abrasion: 0.8

Climatic resistance: А
Resistance to acids: I

Temperature coefficient of linear expansion
Temp. range, C	Value, 1/C*10^-7
-60 ~ 20	71
0 ~ 30	74
20 ~ 120	78
20 ~ 300	85

Temperature coefs. of n_abs
Temp. range, C	Wave length, mkm.	Value, 1/C*10^-6
-60 ~ 20	F	0.6
-60 ~ 20	e	0.3
-60 ~ 20	D	0.2
20 ~ 120	F	2
20 ~ 120	e	1.6
20 ~ 120	D	1.5
20 ~ 120	C	1.3