Page 59 - Modern Optical Engineering The Design of Optical Systems

42 Chapter Three

The ray height at surface #2 is found by Eq. 3.17.
t (n′ u′ )
1
1
1
y y
2 1 n′
1
10 ( 0.0666)
10
1.5
10 0.444
y 9.555
2
Noting that n 2 u 2 n′ 1 u′ 1 , the refraction at the second surface is carried
through by
n′ u′ y (n′ n ) C n u
2 2 2 2 2 2 2 2
9.555 (1.6 1.5) ( 0.02) 0.0666
0.019111 0.0666
0.047555

and the ray height at the third surface is calculated by
t (n′ u′ ) 2( 0.04755)
2
2
2
y y 9.555
n′ 1.6
3 2
2
9.555 0.059444 9.496111
Since the last surface of the system is plane, i.e., of infinite radius, its
curvature is zero and the product nu is unchanged at this surface:
n′ u′ y (n′ n ) C n u
3 3 3 3 3 3 3 3
9.496111 (1.0 1.6) (0) 0.047555 0.047555

and
n′ u′
3
u′ 3 0.047555
n′
3
3
Now the location of the image is given by the final intercept length l′,
which is determined by
9.496111
y 3
l′
3
u′ 0.047555
3
199.6846