BF28 - GOST Rus

Diagram n (λ)

n calculation

Analogue search

Main parameters
n_d = 1.664264 n_e = 1.668706	V_d = 35.44 V_e = 35.18	n_F - n_C = 0.018740 n_F' - n_C' = 0.019007

Type: Resnik
Spectral range: 0.36501 - 2.6 mkm.
C1 = 0.028 C2 = 1.66651 C3 = 0.0363251 C4 = -0.00946195 C5 = 0.000614539 C6 = -0.000345109 C7 = 0.0000583616 C8 = -0.00142691 C9 = 0.000937369 C10 = 0.00121305 C11 = -0.000728504

Refraction index
n _2.3254	1.626762
n _1.9701	1.631825
n _1.5296	1.637337
n _1.06	1.644522
n _t	1.645483
n _s	1.649741
n _r	1.655768
n _C	1.658781
n _C'	1.659639
n _0.6328	1.660446
n _D	1.664101
n _d	1.664264
n _e	1.668706
n _F	1.677522
n _F'	1.678646
n _g	1.688498
n _h	1.698075
n _i	1.715471
n _0.3341	-----
n _0.3126	-----
n _0.2967	-----
n _0.2804	-----
n _0.2483	-----

Relative partial dispertion
P_C,t	0.7095
P_C,A'	0.3174
P_d,C	0.2925
P_e,C	0.5295
P_g,d	1.2930
P_g,F	0.5856
P_h,g	0.5110
P_i,g	1.4392
P_C',t	0.7553
P_e,C'	0.4837
P_F',e	0.5304
P_i,F'	1.9649

Density: 3.96 g/cm³
Poisson coef.: 0.238
Rigidity: 264 Pa*10⁸
Young module: 653.7 Pa*10⁸
Optical stress coef.: 2.4 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	59
0 ~ 30	61
20 ~ 120	65
20 ~ 300	72

Temperature coefs. of n_abs
Temp. range, C	Wave length, mkm.	Value, 1/C*10^-6
-60 ~ 20	F	7.7
-60 ~ 20	e	6.7
-60 ~ 20	D	6.3
-60 ~ 20	C	5.8
20 ~ 120	F	9.7
20 ~ 120	e	8.6
20 ~ 120	D	8.2
20 ~ 120	C	7.7