33. For constructive interference, we use Eq. 36-34: 2n
2
L = (m + 1/2)λ. For the two smallest values of L,
let m = 0 and 1:
L
0
=
λ/2
2n
2
=
624 nm
4(1.33)
= 117 nm = 0.117 µm
L
1
=
(1 + 1/2)λ
2n
2
=
3λ
2n
2
= 3L
0
= 3(0.1173µm) = 0.352 µm .
33. For constructive interference, we use Eq. 36-34: 2n
2
L = (m + 1/2)λ. For the two smallest values of L,
let m = 0 and 1:
L
0
=
λ/2
2n
2
=
624 nm
4(1.33)
= 117 nm = 0.117 µm
L
1
=
(1 + 1/2)λ
2n
2
=
3λ
2n
2
= 3L
0
= 3(0.1173µm) = 0.352 µm .