Abstract

Miniaturized gain media such as optical chips have enabled the design of compact, rugged, and efficient lasers. The design of such a laser emitting around 2.9 µm and whose gain medium is a fluorozirconate ZBLAN optical chip doped with Ho³⁺ and Pr³⁺ is reported here. Pr³⁺ co-doping overcomes the temporal emission instability we have observed with a chip doped with Ho³⁺ only [1], enabling single-frequency and mode-locked operation. Depressed-cladding waveguides were written in the glass chip by ultrafast-laser inscription (ULI) [2]. Multiples waveguides within a single chip provides high mutual coherence between lasers within the same platform [3] and find numerous applications such as in dual-comb spectroscopy [4]. Moreover, as the measurement of the mid-infrared spectral signature of many gas allows a distinctive way to identify them, the operation wavelength of the presented laser makes it an ideal candidate for mid-infrared spectroscopy. In addition, its compactness strengthens its ability to fulfil the need for portable devices.

© 2019 IEEE