Mode-locked all-fiber laser producing radially polarized rectangular pulses

Abstract

We propose and demonstrate a radially polarized mode-locked fiber laser through the use of a figure-8 cavity in combination with cascade fiber Bragg gratings (FBGs). The mode-locked laser emits rectangular pulses with width tunable from 2.8 to 23 ns under an increasing pump power at 1056.3 nm with 0.2-nm 30-dB linewidth. A polarization purity as high as 96% for the output transverse mode has been achieved simultaneously.

A 1- $\mu$ m Cylindrical Vector Beam Fiber Ring Laser Based on a Mode Selective Coupler

“…6, which consists of one 974 nm laser diode (LD), a 980/1064 nm wavelength division multiplexer (WDM), a section of ytterbium-doped-fiber (YDF, Nufern, SM-YSF-HI), a circulator, a single-mode fiber Bragg grating (SM-FBG), two polarization controllers (PCs) and a MSC. By introducing SM-FBG into the cavity to narrow the bandwidth of the laser, the purity of the CVB is increased [15]. MSC act as transverse mode converter and mode splitter.…”

Laguerre-Gaussian mode division multiplexing in multimode fiber using SLMs in VCSEL arrays

“…In previous MDM systems, linearly polarized Laguerre-Gaussian modes have been generated using fiber Bragg gratings lasers [40][41][42], long-period grating lasers [43], separate SLMs [44][45][46][47]7] and photonic crystal fiber [48].…”

A mode-locked fiber laser generating high purity cylindrical vector beams based on a mode selective coupler in a figure-8 cavity

“…In Reference [5] we demonstrated a single-longitudinal-mode fiber ring laser with continuous wave (CW) CVB emission using a two-mode fiber Bragg grating as a transverse mode selector. Recently, pulsed CVB fiber lasers have been reported, using mode-locking or Q switching method [7,8]. Most of these research use offset splicing (OSS) method to generate high-order mode and few-mode fiber Bragg grating (FM-FBG) as the transverse-mode selector.…”