Description
Visible red fibre lasers remain relatively uncommon despite their importance for spectroscopy, biomedical imaging, and quantum technologies. Existing fibre-based red sources are predominantly based on Pr³⁺-doped fibres operating near 635–640 nm, while the well-established He–Ne laser provides emission at 632 nm. In contrast, efficient fibre laser source around 670 nm, remain unavailable, to the best of our knowledge, limiting access to this spectral region in a compact and robust fibre format.
We are investigating an all-fibre visible red laser based on Er³⁺:Tm³⁺ co-doped ZBLAN fibre, enabling lasing near 670 nm through rare-earth upconversion processes. The laser cavity is integrated using fibre Bragg gratings (FBGs) and ZBLAN-to-silica splices forming a fully fibre architecture with standard silica-fibre components. To optimise the cavity design, gain measurements will be conducted to identify the wavelength of maximum optical gain and optimise the FBG reflectivity accordingly. This design is aiming to eliminate free-space alignment while preserving the intrinsic advantages of fibre lasers, including excellent beam quality, compactness and reliable operation.
The low-phonon-energy ZBLAN host enables strong red emission in Er³⁺, while energy-transfer processes between Tm³⁺ to Er³⁺ promote ions through upconversion required for populating the red level. Theoretical laser dynamics experimental spectroscopy performance and our work towards an all-fibre system are presented. This work aims to demonstrate a robust, fully fibre-integrated visible laser and extends the accessible wavelength range of rare-earth fibre lasers towards the 670 nm spectral region.
| I am the presenting author | Yes |
|---|