BF21 - GOST Rus

Diagram n (λ)

n calculation

Analogue search

Main parameters
n_d = 1.614131 n_e = 1.617769	V_d = 40.04 V_e = 39.76	n_F - n_C = 0.015337 n_F' - n_C' = 0.015537

Type: Resnik
Spectral range: 0.36501 - 2.6 mkm.
C1 = 0.028 C2 = 1.61671 C3 = 0.029781 C4 = -0.00908161 C5 = -0.000273931 C6 = -0.000431006 C7 = 0.000248116 C8 = 0 C9 = 0 C10 = 0 C11 = 0

Refraction index
n _2.3254	1.581129
n _1.9701	1.585944
n _1.5296	1.591276
n _1.06	1.597613
n _t	1.598429
n _s	1.602031
n _r	1.607095
n _C	1.609604
n _C'	1.610315
n _0.6328	1.610983
n _D	1.613997
n _d	1.614131
n _e	1.617769
n _F	1.624942
n _F'	1.625852
n _g	1.633792
n _h	1.641423
n _i	1.655113
n _0.3341	-----
n _0.3126	-----
n _0.2967	-----
n _0.2804	-----
n _0.2483	-----

Relative partial dispertion
P_C,t	0.7285
P_C,A'	0.3240
P_d,C	0.2951
P_e,C	0.5323
P_g,d	1.2818
P_g,F	0.5770
P_h,g	0.4975
P_i,g	1.3901
P_C',t	0.7749
P_e,C'	0.4860
P_F',e	0.5269
P_i,F'	1.9077

Density: 3.56 g/cm³
Poisson coef.: 0.235
Rigidity: 251.2 Pa*10⁸
Young module: 620.3 Pa*10⁸
Optical stress coef.: 2.91 1/Pa*10¹²
Abrasion: 0.9

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	73
20 ~ 120	77
20 ~ 300	83

Temperature coefs. of n_abs
Temp. range, C	Wave length, mkm.	Value, 1/C*10^-6
-60 ~ 20	F	3.4
-60 ~ 20	e	2.9
-60 ~ 20	D	2.7
-60 ~ 20	C	2.4
20 ~ 120	F	5.7
20 ~ 120	e	5.1
20 ~ 120	D	4.8
20 ~ 120	C	4.5