Novel ultrafast sources based on fluoride fiber lasers and amplifiers have emerged as a new alternative for the efficient generation of coherent broadband signal in the mid-infrared (> 3 µm). It was shown recently that the amplification of a 2.8-µm ultrafast signal using Er3+: fluoride fiber leads to different output regimes in the mid-infrared (supercontinuum or tunable femtosecond pulses) depending on the input signal properties. Here, we study the underlying mechanisms that affect the amplification and spectral conversion dynamics of ultrashort pulses inside such amplifier through a complete numerical model based on accurate measurements of the amplifier properties. The numerical results, which are in very good agreement with the experiment, show an enhanced output stability due to the attractor properties of the amplifier and the possibility of generating a supercontinuum extending from 2.8 to 4.2 µm with more than 4 W of average power using off-the-shelf fluorozirconate fibers. By designing the appropriate amplifier, tunable and spectrally isolated femtosecond solitons with peak power up to 400 kW around 3.4 µm that can be shifted up to 4 µm could also be achieved. Future perspectives with novel mid-IR laser transitions and different fluoride glass compositions with extended transmission are also discussed.
During the 2015 International Year of Light, Université Laval's SPIE Student Chapter volunteered to create a fully autonomous exhibition explaining the basics of light to the public. Composed of two informative banners and four modules each displaying a live experiment related to both fundamental and technological aspects of light, the goal of the exhibit A Meeting with Light was to illustrate the importance of light-based technologies and their role in our daily lives. Following its debut on campus, the exhibit traveled to several public libraries and major events such as Photonics North, IONS Québec and career fairs. Originating from student initiative and dedicated volunteer work from the Student Chapter, the project was made financially viable through a close collaboration with SPIE, The Optical Society (OSA) and partnerships with local optics-related companies. <p> </p>Now more than two years after its first exposition and since meeting over 2000 people, it is possible to evaluate the factors that contributed to the success of the exhibit and of its continued use. A Meeting with Light is a great example of an outreach project that successfully reached its goal of promoting optics and photonics to a broader audience. In doing so, it brought together local leaders from academia, industry and government. We will discuss lessons learned by the Student Chapter in developing such a project, and we will hint at how it in influenced our next major outreach project for the first International Day of Light in May 2018.
The recent development of soliton femtosecond fiber lasers emitting at 2.8 μm opens a new avenue for the generation of ultrashort pulses in the mid-infrared spectral region. In this paper, we investigate the peak power scalability of such lasers. By optimizing the output coupling ratio and the length of the Er<sup>3+</sup>: fluoride fiber in the cavity, we demonstrate the generation of 270-fs pulses with an energy of 7 nJ and an estimated peak power of 23 kW. These record performances at 2.8 μm surpass by far those obtained from standard soliton lasers at 1.55 μm. A numerical model of the laser including the effect of the intracavity atmospheric absorption is also presented. Numerical simulations agree well with the experimental results and suggest that the atmospheric propagation in the cavity could prevent the laser from self-starting in a mode-locked regime. This femtosecond laser could be the building block for simple and compact mid-infrared frequency combs and supercontinuum sources.