Single-mode ZBLAN Fiber Research Articles

Mid-IR supercontinuum pumped by femtosecond pulses from thulium doped all-fiber amplifier.

We present a mid-infrared (mid-IR) supercontinuum (SC) light source pumped by femtosecond pulses from a thulium doped fiber amplifier (TDFA) at 2 μm. An octave-spanning spectrum from 1.1 to 3.7 μm with an average power of 253 mW has been obtained from a single mode ZBLAN fiber. Spectral flatness of 10 dB over a 1390 nm range has been obtained in the mid-IR region from 1940 - 3330 nm. It is resulted from the enhanced self phase modulation process in femtosecond regime. The all-fiber configuration makes such broadband coherent source a compact candidate for various applications.

Mid-IR supercontinuum generation in a ZBLAN fiber pumped by a gain-switched mode-locked Tm-doped fiber laser and amplifier system

We demonstrate a novel method of mid-infrared (mid-IR) supercontinuum (SC) generation with the use of a 2 µm gain-switched self-mode-locked thulium-doped fiber laser. SC radiation ranging from ~1.9 to 3.8 µm wavelength, generated in a single-mode ZBLAN fiber with a zero-dispersion wavelength (ZDW) shifted to ~1.9 µm, is reported. An average output power of 0.74 W with 0.27 W at wavelengths longer than 2.4 µm was measured. It is, to the best of our knowledge, the first report on such an approach to generate a mid-IR SC in optical fibers.

Stimulated Brillouin scattering in SM ZBLAN fiber

ZBLAN fiber has been vastly investigated over the past decades since it has a broad wavelength transparent region. Therefore, to use it at its maximum potential in multiple applications such as in fiber lasers, amplifiers, laser cooling or infrared super continuum generation, it is important to know its intrinsic material properties. We have investigated stimulated Brillouin scattering in a single mode ZBLAN fiber, we believe for the first time, for crucial information on acousto-optic properties. A frequency shift of 7.76GHz from the pump is observed and the Brillouin gain bandwidth is measured to be 38MHz. We compared this data to a standard SMF-28 fiber and bulk ZBLAN. We calculate fundamental properties in the fiber such as phonon lifetime, attenuation and longitudinal velocity, the electrostrictive constant, the longitudinal elasto-optic Pockels coefficient and the maximum Brillouin gain constant.

Soliton delivery of mid-IR femtosecond pulses with ZBLAN fiber

We demonstrate environmentally protected delivery of high-power femtosecond mid-IR pulses in a single-mode ZBLAN fiber by soliton formation. A 70-fs Cr:ZnS laser at 2.4 µm reaches this regime already at ~2 nJ launched pulse energy, while a 110-fs pulse can be transmitted without visible shortening over meters of fiber. We also measured the nonlinear-optical coefficient of ZBLAN as n2 = 2.7 ± 0.2 × 10−16 cm2/W at 2.4 µm wavelength.

Passively Q-Switched 2.8-$\mu{\rm m}$ Nanosecond Fiber Laser

A diode-pumped erbium ion-doped single-mode ZBLAN fiber laser passively Q-switched by a Fe <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> :ZnSe crystal is reported. Mid-infrared (MIR) pulses at 2.8 μm with a pulse energy of 2.0 μJ and pulse duration of 370 ns, corresponding to a peak power of 5.34 W, are achieved at a repetition rate of 161 kHz. Our experiment demonstrates that Fe <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> : ZnSe crystal is a promising Q-switching element for high power pulsed MIR fiber lasers.