BF25 - GOST Rus

Diagram n (λ)

n calculation

Analogue search

Main parameters
n_d = 1.607722 n_e = 1.610854	V_d = 46.10 V_e = 45.81	n_F - n_C = 0.013180 n_F' - n_C' = 0.013333

Type: Resnik
Spectral range: 0.36501 - 2.6 mkm.
C1 = 0.028 C2 = 1.60842 C3 = 0.0250868 C4 = -0.0090787 C5 = -0.000709213 C6 = -0.000635351 C7 = 0.0000691821 C8 = 0.00000328349 C9 = 0.0000815051 C10 = 0.00056259 C11 = 0

Refraction index
n _2.3254	1.577321
n _1.9701	1.582060
n _1.5296	1.587206
n _1.06	1.593122
n _t	1.593869
n _s	1.597122
n _r	1.601602
n _C	1.603795
n _C'	1.604414
n _0.6328	1.604995
n _D	1.607606
n _d	1.607722
n _e	1.610854
n _F	1.616975
n _F'	1.617748
n _g	1.624430
n _h	1.630768
n _i	1.641949
n _0.3341	-----
n _0.3126	-----
n _0.2967	-----
n _0.2804	-----
n _0.2483	-----

Relative partial dispertion
P_C,t	0.7530
P_C,A'	0.3307
P_d,C	0.2979
P_e,C	0.5355
P_g,d	1.2676
P_g,F	0.5655
P_h,g	0.4808
P_i,g	1.3291
P_C',t	0.8000
P_e,C'	0.4886
P_F',e	0.5229
P_i,F'	1.8361

Density: 3.47 g/cm³
Poisson coef.: 0.25
Rigidity: 288.1 Pa*10⁸
Young module: 720.3 Pa*10⁸
Optical stress coef.: 2.8 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	66
0 ~ 30	69
20 ~ 120	73
20 ~ 300	81

Temperature coefs. of n_abs
Temp. range, C	Wave length, mkm.	Value, 1/C*10^-6
-60 ~ 20	F	3.9
-60 ~ 20	e	3.4
-60 ~ 20	D	3.1
-60 ~ 20	C	2.8
20 ~ 120	F	5.6
20 ~ 120	e	5.1
20 ~ 120	D	4.9
20 ~ 120	C	4.6