wave plate

        The wave plate, also known as the phase retarder, makes the two mutually orthogonal polarization components passing through the wave plate shift the phase, which can be used to adjust the polarization state of the light beam. When ordering a waveplate, you need to specify the wavelength, phase, aperture and specific waveplate type (zero-order or multi-order). The wave plate can be installed in the metal holder according to the customer's request. Our company provides most common wavelengths for customers to purchase, and can also customize wave plates with special phases and special wavelengths according to customer requirements. Common wave plates are made of quartz crystals, mainly half wave plates (also called half wave plates) and quarter wave plates. The main uses are as follows.

        Half-wave plate: After the linearly polarized light passes through the half-wave plate, it is still linearly polarized light, but the vibration plane of its combined vibration and the vibration plane of the incident polarized light are rotated by 2θ. If θ=45°, the vibration plane of the outgoing light is perpendicular to the vibration plane of the original incident light, that is to say, when θ=45°, the half-wave plate can rotate the polarization state by 90°. The half-wave plate can also be used with PBS. By rotating the half-wave plate, we can realize a beam splitting prism with variable splitting ratio.

        Quarter wave plate: When the angle θ between the incident vibration plane of the polarized light and the optical axis of the wave plate is 45°, the light passing through the quarter wave plate is circularly polarized light. After a wave plate, it becomes linearly polarized light. When light passes through a quarter-wave plate twice, it acts as a half-wave plate. The quarter wave plate can also be used with PBS to realize the function of optical isolator.

        How to choose wave plate?

        First, to determine the phase delay, one-half or one-quarter? Or a special phase?

        Second, determine the size and wavelength.

        Finally, determine the type of waveplate. If you want the waveplate to be used over a wide temperature range and a wide wavelength range, you should choose a zero-order or true zero-order waveplate. For zero-order waveplates, the glued zero-order price is relatively cheap, and the zero-order damage threshold of the optical glue and the zero-order of the air gap are high. The parallelism and wavefront distortion of true zero-order waveplates are the best and are used in systems of particular importance. If you have no requirements for wavelength bandwidth and temperature bandwidth, multi-stage waveplates should be a cost-effective choice. If you need more than 100nm wavelength bandwidth, you should choose an achromatic waveplate.