OPERATION
Axioskop
2
plus
Carl Zeiss
Illumination and contrasting techniques
Axioskop 2
mot plus
3-34
B 40-075 e 02/01
(4) Conclusions
The grayish white color first occurring in the bright position in the above example corresponds to a path
difference of 150 nm, according to the Michel Lévy color chart (3-24).
The "surrounding" of the artificial fiber, which is not birefringent, displays a dark red when the
compensator
λ
is inserted, which corresponds to the path difference of the compensator of 550 nm
(1
st
order interference color for the path difference 550 nm, corresponds to 1
λ
).
If the vibration direction of the birefringent specimen to be examined is parallel to the largest vibration
direction of the compensator
λ
, i.e. in NE-SW direction, the path difference of the specimen (e.g. grayish
white: 150 nm) and the path difference of the compensator
λ
(red: 550 nm) add up. This results in a
color change of the specimen from grayish white to greenish blue (resulting path difference = 700 nm).
If the vibration direction of the specimen to be examined is perpendicular to the largest vibration
direction of the compensator
λ
, i.e. in NW-SE direction, the path difference of the specimen (e.g. grayish
white: 150 nm) is subtracted from the path difference of the compensator
λ
(red: 550 nm). A change in
the interference color of the specimen from grayish white to orange (resulting path difference = 400 nm)
then becomes visible.
☞
Michel Lévy color charts are available under order No. 42-312.
