Mechanical three-ring polarization control is made using the principle of induced birefringence of an optical fiber under external force. Three of the rings are equivalent to three wave plates of λ/4, λ/2, and λ/4, respectively. The light wave is converted into linearly polarized light by the λ/4 wave plate, and then the polarization direction is adjusted by the λ/2 wave plate. Finally, the polarization state of the linearly polarized light is changed to an arbitrary polarization state via the λ/4 wave plate.The retardation effect caused by the birefringence effect is mainly determined by the cladding radius of the fiber, the surrounding radius of the fiber, and the wavelength of the light wave. It is verified that the controller can generate a change in the omnidirectional polarization state, and the adjusted polarization state can cover the entire Pangga sphere.

Feature

Equivalent to λ/2, λ/4 optical wave plates

Adjustable to any polarization point on the Pangga ball

Low insertion loss, wide wavelength operating range

Excellent workmanship and low price

Easy to disassemble, you can replace and wrap the fiber

Application

Single mode to polarization-maintaining fiber applications

Polarization dependent loss measurement (PDL)

Application of polarization sensitive devices

fiber-optic laser

The relationship between single-ring delay of polarization controller and wavelength and number of turns (Test unit: fiber ring diameter 56mm, fiber cladding diameter 125μm)

For example, the polarization controller fiber ring has a fixed diameter of 56 mm, and a single mode fiber with a cladding diameter of 125 μm is wound therein; when λ=1550 nm, the circle number loop=1, the ring is equivalent to a λ/2 wave plate;

When λ = 1550 nm and the number of turns around loop = 3, the ring is equivalent to a 3λ/2 wave plate.