We proposed and demonstrated the application of a polarization-maintaining photonic crystal fiber for torsion sensing. The sensor has high twist angle resolution and exhibits reduced temperature sensitivity, making it an ideal candidate for torsion sensing.

We present the design of a short broadband fiber directional coupler for terahertz (THz) radiation and demonstrate a 3 dB coupler with a bandwidth of 0.6 THz centered at 1.4 THz. The broadband coupling is achieved by mechanically downdoping the cores of a dual-core photonic crystal fiber by microstructuring the cores. This is equivalent to chemical downdoping but is easier to realize experiment...

Brillouin scattering is a fundamental nonlinear opto-acoustic interaction present in optical fibers with important implications in fields ranging from modern telecommunication networks to smart optical fiber sensors. This thesis is aimed at providing a comprehensive theoretical and experimental investigation of both forward and backward Brillouin scattering in next generation photonic crystal f...

Phase-matched four-wave mixing is demonstrated for millijoule nanosecond pulses guided by photonic bandgaps of hollow fibers with a two-dimensionally periodic cladding and a core diameter of 50 m. Raman resonances related to the stretching vibrations of water molecules inside the hollow fiber core are detected in the spectrum of the four-wave mixing signal, suggesting phase-matched coherent ant...

Microstructured optical fibers (MOFs) are one of the most exciting recent developments in fiber optics. A MOF usually consists of a hexagonal arrangement of air holes running down the length of a silica fiber surrounding a central core of solid silica or, in some cases air. MOFs can exhibit a number of unique properties, including zero dispersion at visible wavelengths and low or high effective...

Recently, photonic crystal fibers (PCFs) have attracted many researchers because of their unique properties, and design flexibility that can’t be realized by conventional fibers. One of the fruitful areas of research is the optical fiber hydrophone. In this paper, the finite element solver (FES), COMSOL multiphysics, is used to study and compare the response to acoustic pressure of a hollow-cor...

We show theoretically that photonic crystal membranes cause large variations in the spontaneous emission rate of dipole emitters, not only inside but also in the near field above the membranes. Our three-dimensional finite-difference time-domain calculations reveal an inhibition of more than five times and an enhancement of more than ten times for the spontaneous emission rate of emitters with ...