26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Advances and Challenges of Visible Silica Fiber Lasers: Revisiting 650 nm Red Spectral Band

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral ANZOS | Photonics and Optics (ANZCOP)

Speaker

Dr Yan Ososkov

Description

Visible fiber lasers are attracting increasing research attention due to their potential applications in biophotonics, display systems, laser processing, etc. [1]. Among available glass hosts, silica offers unmatched mechanical robustness, chemical durability, and technological maturity, making it particularly attractive for deployment outside the laboratory. Despite these advantages, visible silica fiber lasers remain scarce, with reported output powers only recently surpassing the 100-mW milestone [2]. Their development has been hindered by photodarkening (PD), a degradation of the host glass transmission that remains poorly understood and continues to limit laser performance.

The first red silica fiber laser was demonstrated nearly four decades ago using a Samarium-doped germanosilicate fiber. Pumped by a 488 nm Argon laser, the device exhibited significant output degradation within the first 20 minutes of operation [3][4]. No silica fiber lasers in this spectral region have been reported since that pioneering work.

In this study, we approached red laser operation in silica fibers using an alumino-phosphosilicate (APS) glass composition initially designed to mitigate photodarkening. We further investigate the influence of pump wavelength and show that 488 nm excitation induces substantially less photodarkening than 405 nm excitation [5]. The combination of APS glass and optimized pumping enables red laser generation, demonstrating partial viability of this approach for overcoming the PD limitations. Finally, we propose a potential mechanism responsible for photodarkening in APS glass fibers under 405/488 nm excitation.

References
[1] Fujimoto, Yasushi, et al., Progress in Quantum Electronics 37.4 (2013): 185-214.
[2] Lee, Jinho, et al., Optics Letters 50.4 (2025): 1148-1151.
[3] Farries, M. C., P. R. Morkel, and J. E. Townsend, Electronics Letters 24.11 (1988): 709-711.
[4] Cheng, Yu, et al., Conference on Lasers and Electro-Optics/Pacific Rim. Optica Publishing Group, 2009.
[5] Ososkov, Yan, Jinho Lee, and Stuart D. Jackson, Optical Materials Express 14.9 (2024): 2148-2160.