Wavelength-locked vectorial fiber laser manipulated by Pancharatnam-Berry phase

Abstract

We report a wavelength-locked cladding-pumped ytterbium-doped fiber laser that can simultaneously emit radially and azimuthally polarized beams based on Pancharatnam-Berry phase optical elements. Multi-wavelength free running operation of the radially and azimuthally polarized laser beams can be switched to a single-wavelength one assisted by volume Bragg grating, with wavelength locked at around 1053.4 nm and spectral linewidth of 0.06 nm (FWHW). By rotating the glan-taylor polarizer, we can obtain switchable radially and azimuthally polarized beams output. The radially and azimuthally polarized beams mode purity can maintain 97.3% and 96.3% at maximum output power, and the polarization extinction ratio (PER) can reach 97.8% and 95.9% for the radially and azimuthally polarized laser, respectively.

Controlled higher-order transverse mode conversion from a fiber laser by polarization manipulation

“…We could see that the observed intensity profiles of LP 11 modes passed through the polarization analyzer agrees well with the theoretical results [22]. In order to further make sure that the output beams have the same polarization distributions with the theoretical results, we have measured the Stokes parameters of the four modes [23]. The experimental results of the specific polarization state distributions of the four modes have been shown in figure 5.…”

“…However, these methods suffer from the poor mode purity, low conversion efficiency or the complex experimental setup. Compared to the extra-cavity methods, the intra-cavity generation methods can exhibit some unique advantages, such as compactness, high efficiency and high mode purity [22,23]. Sun et al have obtained the four second-order modes by exploiting the particular wavelength-dependent characteristics of the few-mode fiber Bragg grating [20].…”

“…However, the highest slope efficiency of this transverse switchable fiber laser is about 3.6%. We reported a high efficient and compact fiber laser with switchable radially and azimuthally output by using the low-loss q-plate [23], but it cannot deliver the hybrid modes.…”

Ferroelectric Liquid Crystal Compound Lens Based on Pancharatnam–Berry Phase

“…Several well-known optical elements use the PB phase, including the PB lens [10,11], polarization grating (PG) [12] and the q-plate [13]. They are widely used for the shaping of various wavefronts, such as a helical wavefront for vortex beams [9] and vector beams [14], as well as laser beam shaping [15]. With the help of LC photoalignment technology [16,17], it is becoming possible to realize complex micro-sized LC structures.…”

All-fiber single-longitudinal-mode narrow linewidth fiber ring laser with cylindrical vector beam output

“…Attributing to the axially symmetric polarization and field intensity distribution, numerous applications have been explored in fields such as optical tweezers [3], optical communications [4,5], surface plasmon resonance [6] and material processing [7]. The generation of CVBs in fibers or fiber lasers captures increasing interest due to the merits of compactness, excellent flexibility and stability while the generation methods in free space such as using phase plate [8], spatial light modulator [9], birefringent effect [10] and interference technology [11] suffer from the insertion loss and alignment issues in applications of fiberbased communication, sensing and nonlinear fiber optics. For a two-mode fiber (TMF), the first group high-order mode LP 11 includes radially polarized (TM 01 ), azimuthally polarized (TE 01 ) and hybridly polarized (HE odd 21 and HE even 21 ) vector modes.…”