Motorized Fiber Polarization Controllers

Motorized Fiber
Polarization Controllers

Motorized Fiber Polarization Controllers

Model：Clairvo-PCM182C01
Model：Clairvo-PCM183C03

Conversion between linear, circular and elliptical polarization state
2 paddle version with 18 mm loop diameter
3 paddle version with 26.9 mm or 5.58 mm loop diameter
Control mode: USB control

Principle

The fiber polarization controller induces stress birefringence by winding the fiber around two or three circular paddles, forming independent waveplates that alter the polarization state of light propagating in single-mode fibers. The fast axis of the fiber lies in the plane of the winding paddles, allowing the polarization state of any input light to be adjusted by rotating the paddles.

Our company offers fiberless controllers, enabling users to insert single-mode fibers with a Ø900 µm buffer coating, or FC/PC or FC/APC fiber patch cords. To ensure proper operation of the controller, the patch cord must be sufficiently long to achieve the recommended number of turns.

The retardation of each paddle can be estimated using the following equation:

Here, φ is the retardation, a is a constant (a = 0.133 for silica fiber), N is the number of turns, d is the fiber cladding diameter, λ is the wavelength, and D is the coil diameter. This equation is derived for bare fiber, but the result is also sufficiently applicable for fiber with a Ø900 µm buffer coating (i.e., for fiber with a Ø900 µm buffer coating, the result does not vary with the number of turns N).

Product Introduction

Motorized Dual-Loop Polarization Controller

For fiber with Ø900 µm buffer coating, dual‑loop, Ø18 mm

This compact dual‑loop polarization controller uses two quarter‑waveplates to convert any input polarization state into another. However, in a dual‑loop configuration, polarization control results from the coupling of the two loops, which may make it difficult to achieve a specific target polarization state.

The design of our polarization controller enables full control of the output polarization state over a wavelength range of 300 nm – 2100 nm.

Note that for the motorized polarization controller we provide, only one loop is motor‑driven, while the other must be manually adjusted and fixed.

Motorized Three-Loop Polarization Controller

The three-loop polarization controller integrates a quarter-waveplate, a half-waveplate, and a quarter-waveplate in series, enabling the conversion of any input polarization state into any arbitrary output polarization state.

First, the first quarter-waveplate converts the polarization state of the incident light into linear polarization.The half-waveplate then rotates the linearly polarized light.Finally, the last quarter-waveplate transforms the linear polarization into a fixed output polarization state.

Therefore, by adjusting the three loops (fiber retarders) in the polarization controller, full control of the output polarization state can be achieved over the wavelength range of 300 nm – 2100 nm.