Share the benefits of wave plates

Achromatic waveplates are assembled by placing an etched stainless steel gasket between two birefringent waveplates and bonding the three pieces together with epoxy resin. The adhesive is only applied to the outer edge of the clear aperture of the waveplate. The direction of the fast axis of the wave plate is marked with a pencil on the three-piece bonded part in addition to the marking on the housing.

If the customer has special requirements, the wave plate can be disassembled from the shell and used for customization or OEM. By aligning the fast axis of the multi-level crystal quartz wave plate with the slow axis of the magnesium fluoride wave plate, a zero-order achromatic wave plate can be obtained, and the optical path difference of the two wave plates is λ/4 or λ/2. Crystalline quartz and magnesium fluoride minimize dispersion, resulting in a nominally flat spectral response over the operating range of the achromatic waveplate. Cemented zero-order waveplates are usually composed of two pieces of quartz with orthogonal optical axes.

How to distinguish the fast and slow axes of the wave plate? Although the two orthogonal axes of the wave plate are easy to identify, how to distinguish the fast and slow axes is more complicated. In the tutorial on generating circularly polarized light with a quarter wave plate, we used a pair of crossed polarizers to find a principal axis, but it did not distinguish whether it was the fast axis or the slow axis, so there was no distinction between the chirality of circularly polarized light. However, if a metal film mirror is added to the device, we can confirm the fast and slow axes of the wave plate by comparing the actual and theoretical values ​​of reflected power.

Under the visual angle facing the beam propagation, if the fast axis of the wave plate is vertical, the transmitted light of the wave plate becomes right-handed circularly polarized light. When the fast axis level is constant, the polarization weight of the vertical axis is delayed more, and the rotation direction of the circularly polarized light is reversed, so the light becomes left-handed circularly polarized.