Integrated-optic polarization transformer for reset-free endless polarization control

Tunable and rotatable polarization controller using photonic crystal fiber filled with liquid crystal

“…Some methods for achieving polarization transformations have been developed, such as mechanical squeezing of fibers, 1 rotating wave plates, 2 electrooptic crystal waveguides, 3 and liquid crystal ͑LC͒ retarders. 4 With the recent development of photonic crystal fibers ͑PCFs͒, SOP control was proposed by using thermal tuning of the refractive index of a polymer partially infiltrated in some of the air-holes of PCF.…”

Polarization Control with Piezoelectric and LiNbO3 Transducers

“…The three-stage LiNbO3 Polarization Control Transducer (PCT) of reference [6] can in principle offer reset-free operation, but fabrication tolerances, wavelength dependencies, PDL, etc. conspire to degrade performance from theoretically obtainable levels [4]. If this results in the inability to perform certain polarization transformations, then reset-free operation will likely be compromised.…”

“…Although the reset can be implemented with algorithms that avoid a discontinuity in the signal [3], the overall system complexity and speed of response are adversely affected. Other transducers claim to offer reset-free control [4][5][6]. The three-stage LiNbO3 Polarization Control Transducer (PCT) of reference [6] can in principle offer reset-free operation, but fabrication tolerances, wavelength dependencies, PDL, etc.…”

Realization of microcontroller-based polarization control system with genetic algorithm

“…There have been several technologies to realize polarization controller were introduced in the last two decades such as: mechanically rotating crystal wave plates or fiber loops, fiber squeezers or quartz with piezo electric elements [16], rotating wave plates [17], [13], [18], [11], variable retarder plates [19], liquid crystals [20], and waveguide devices such as LiNbO 3 [13], [21], [11], [22].…”