ID:
2358
Maker's Name:
B&L
Dimensions:
11 × 11 × 2.7 cm
Very fine parallel lines have been traced with a diamond stylus across the surface of the glass. There are 150 lines per mm. Thus the lines are 500 nanometres apart.
Light reflecting off the suface of the glass is diffracted. Different wavelengths are diffracted at slightly different angles, thus eg splitting white light into its component colours.
