Supercontinuum self-Q-switched ytterbium fiber laser

Abstract

We have discovered a new mechanism for passive Q switching of fiber lasers. 10-kW peak power pulses with ~2-ns pulse widths are reported from a diode-pumped ytterbium-doped fiber laser. The laser generates a high-brightness Raman-dominated supercontinuum spectrum covering the complete window of transparency of silica fiber in the infrared from 1.06 to 2.3 mum.

Repetition rate stabilization of the SBS Q-switched fiber laser by external injection

“…As the pulse duration is mainly dependent on the photon lifetime of resonant cavity, short pulses are hardly achieved in long cavity fiber laser by conventional Q-switched mechanisms. Recently, Q-switched fiber lasers with a Rayleigh-SBS ring mirror successfully generated nanoseconds pulses, much shorter than the round trip time of fiber resonator length [4,5]. The SBS process will supply an intensive and fast transient feedback to generate higher peak power Q-switched pulses much narrower than that by other Q-switches.…”

“…With assistance of other technologies, such as hybrid Q switching or coherent combination, the peak power of SBS pulse can be raised to a higher level [6,7]. However, SBS Q-switched pulse has a drawback of repetition rate instability, which comes from the thermal noise incorporated in Brillouin scattering process, and has been observed experimentally [4][5][6][7]. Reference 4 proposed that the enhancement the stabilization of the repetition rate can be achieved by modulating pump power, but did not present experiment data.…”

Pulsed-source and swept-source spectral-domain optical coherence tomography with reduced motion artifacts

“…For example, Q-switching and cavity dumping are well known techniques applicable to ultrashort pulsed lasers. 17 Q-switched supercontinuum sources with repetition rates of a few to tens of kHz have been reported and may be suitable for use in SD-OCT. 18,19 Beside the benefit of reducing motion artifacts, the reduced fringe washout of the pulsed source approach may also facilitate quadrature fringe detection based on sinusoidal phase dithering. 4,20 The use of a wavelength swept source as described in this manuscript is essentially a hybrid between OFDI and SD-OCT that may permit otherwise stringent OFDI source requirements including narrow instantaneous linewidth and tuning linearity to be relaxed.…”

Gain-switched all-fiber laser with narrow bandwidth

“…To overcome the limitation of amplified spontaneous emission (ASE) and catastrophic self-pulsation of the amplifier at the low repetition rate we chose to use a pulse-pumped power amplification scheme [8,20].…”

“…The fiber geometry allows for a very high single pass gain of more than 50 dB, which is advantageous in amplifiers. However, the high gain increases the requirements for the contrast of a Q-switching element and is the origin of often destructive self-pulsation [8].…”