No abstract

Characteristics of guided acoustic wave Brillouin scattering in polarization maintaining fibers are investigated theoretically and experimentally. Spectra of polarized and depolarized scatt.ering are measured for two different types of polarization maintaining fibers: the PANDA (polarization maintaining and absorption reducing) fibers and the elliptical-jacket fibers. Calculated results are in agreement with the experimental ones in the low frequency region.

A new scheme of symmetric and asymmetric fiber loop mirrors is proposed to identify clearly the polarized guided-acoustic-wave Brillouin scattering spectra with multimode laser sources. The guided-acoustic-wave Brillouin scattering spectra in PANDA fibers in the low-frequency region are unambiguously confirmed with this scheme.

Efficient squeezing at low pump light power is demonstrated with a mode-locked 1.064 µm Nd:YAG laser and a fiber ring reflector made of 0.85 µm single-mode fiber. Noise reduction of about 2.0 dB below the shot noise level is observed. The squeezing process by the optical Kerr effect is calculated with a simple model. The experimental results are in good agreement with the calculated ones.