Ultrafast Dy³⁺:fluoride fiber laser beyond 3 μm

Abstract

We report a passively mode-locked Dy 3 :fluoride fiber laser emitting around 3.1 μm based on the nonlinear polarization evolution technique in a ring configuration, using in-band pumping at 2.8 μm. Transform-limited and selfstarting mode-locked pulses as short as 828 fs with a center wavelength around 3.1 μm and repetition rates up to 60 MHz are obtained. In the single-pulse regime, a maximum average output power of 204 mW is measured, corresponding to a peak power of 4.2 kW and a pulse energy of 4.8 nJ. This first demonstration, to the best of our knowledge, of a femtosecond mode-locked fiber laser emitting directly beyond 3 μm paves the way for frequency comb synthesis in the molecular fingerprint region.

Soliton Mode-Locked Large-Mode-Area Tm-Doped Fiber Oscillator

“…We note that the Kelly sidebands in the optical spectrum which is similar to that of Ref. [28], are much stronger than previously reported soliton mode-locked fiber lasers [6][7][8][9]. This is due to the fact that the amplitude of soliton pulse circulating in this laser cavity experiences strong periodic perturbations induced by the significantly discrete losses mentioned above and rapidly variable gain across the bent active fiber [29].…”

Mode-locked 2.8-μm fluoride fiber laser: from soliton to breathing pulse

“…Femtosecond soliton mode-locking has been realized from fluoride fiber lasers near a wavelength of 3 μm using the nonlinear polarization rotation (NPR) technique. [6][7][8][9] These soliton mode-locked lasers generally have a nanojoule-order pulse energy and peak power of the order of 10 kW. However, many mid-IR applications, such as supercontinuum generation and material modification, require a higher pulse energy and peak power, [10][11][12] which are challenging to achieve in MLFFLs.…”

“…In MLFFLs, fluoride fibers several meters long generally have a large anomalous dispersion (∼ − 10 5 fs 2 ) at an operation wavelength of 2.8 μm. [6][7][8][9] It is nearly impractical to compensate for such a large anomalous dispersion using general bulk materials with normal GVD. However, we find that semiconductor material possesses a huge normal GVD near the absorption edge, which results from the rapid change of refractive index.…”

Dysprosium Mid‐Infrared Lasers: Current Status and Future Prospects

“…Experimental layout of a Dy NPE mode‐locked laser. Reproduced with permission . Copyright 2019, OSA.…”