Optical fibers polarization-maintaining

Piliarik, M., Homola, J., Mamkova, Z., Ctyroky, J. (2003) Surface plasmon resonance sensor based on a single-mode polarization-maintaining optical fiber. Sensors and Actuators B 90 236-242. 

Suzuki, K., Kubota, H., Kawanishi, S. et al., Optical properties of a low-loss polarization-maintaining photonic crystal fiber, Opt. Express, 9, 676, 2001. 

Transparent amorphous polymers such as poly(methyl methacrylate) (PMMA) have been found to be useful materials for polymer optical fibers (POFs) (1,2), waveguides (3), lenses (4), optical disks (5), and other optical components because of their excellent mechanical properties and easy processing. Many recently developed optical applications utilizing polarization techniques need optical polymers for maintaining more accurate polarization. However, applications of optical polymers are limited by birefringence which occurs in the process of device fabrication. 

It is well known that when a light with a linear polarization plane propagates through an optical fiber, its state of polarization will not be maintained and it varies with time due to imperfection (birefringence) of the fiber. Therefore, an optical device with performances independent of the polarization variation is desirable when used in a fiber optic system. A polarization-independent optical isolator is developed to fit this need. Polarization-independent optical isolators are normally pigtailed with input and output fibers and are also called in-line-type isolators. 

Fig. 4 (a) The D1 transitions coupled by a fiequency modulated coupling field and two probe fields (one as the signal Qs and another as the control Qc) behaves as the coherently coupled three-level A-type system. The spontaneous decay rate of the excited state 3> is 73 (=271x5.4x10 s for the 5Pi/2 F =3 state), (b) Simplified diagram of the experimental set up. AOM acousto-optic modulator EOM electro-optic modulator, PMF polarization maintaining fiber X/4 quarter-wave plate DL extended-cavity diode laser, M mirror, D photodetector. 

Al-Qaisi, M. K. Akkin, T., Polarization-Sensitive Optical Coherence Tomography Based on Polarization-Maintaining Fibers and Frequency Multiplexing , Optics Express 2008,16, 13032-13041. 

In many of the examples below, the unperturbed fiber has a circularly symmetric cross-section and profile. For perturbations which maintain this symmetry, the polarization of each mode is unchanged, and obeys the rules laid down in Sections 13-4 and 13-7. However, for perturbations which break circular symmetry, the modes are polarized along the optical axes and y of the perturbed fiber. Only the fundamental and HE, modes remain plane polarized on the circular and noncircular fibers. If the perturbation is sufficiently small, the polarization of all other modes lies in the transition region between the circular and noncircular situations, as discussed in Section 13-9. 

---