ORCID Profile
0000-0002-5966-9951
Current Organisations
University of South Australia
,
University of Engineering and Technology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Optica Publishing Group
Date: 2020
DOI: 10.1364/CLEOPR.2020.C3A_4
Abstract: A new Yb 3+ /Ho 3+ co-doped germanate glass is fabricated and its spectroscopic properties are investigated to present its suitability as a potential gain medium for 2 pm laser operation. Rate equations are further applied to study the 2 pm laser characteristics of the glass pumped at 976 nm. The simulation shows that 15 % laser slope efficiency can be achieved at 2050 nm by reducing the intracavity losses below 0.5 dB.
Publisher: The Optical Society
Date: 08-2019
DOI: 10.1364/OME.9.003557
Publisher: Elsevier BV
Date: 2023
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539820
Publisher: Optica Publishing Group
Date: 12-10-2020
DOI: 10.1364/OME.404375
Abstract: The potential of a Yb 3+ /Ho 3+ co-doped lead-germanate glass as a laser gain medium around 2 µm is investigated by spectroscopic measurements and rate equation modelling. The glass, based on the molar composition of 56GeO 2 -31PbO-4Ga 2 O 3 -9Na 2 O and co-doped with 1.5 mol% Yb 2 O 3 and 0.4 mol% Ho 2 O 3 , possesses a broad Ho 3+ emission spectrum covering ∼1.8 µm to 2.2 µm for the Ho 3+ : 5 I 7 → 5 I 8 transition, and a long 5 I 7 fluorescence lifetime of (7.74 ± 0.03) ms. We estimate a competitive 2 µm quantum efficiency (76%) compared to other germanate glasses. The intensity parameters are calculated to be Ω 2 = 3.0×10 −20 cm 2 , Ω 4 = 1.2×10 −20 cm 2 and Ω 6 = 2.0×10 −20 cm 2 . The energy transfer analysis from Ho 3+ to OH group represents a low Ho 3+ -OH clustering factor ( γ = 0.15) compared to phosphate and other germanate glasses. Applying these parameters to the laser model predicts 15% laser slope efficiency for cavity losses ≤ 0.5 dB using 976 nm pumping. The results show that this Yb 3+ /Ho 3+ co-doped lead-germanate glass is a promising candidate for efficient lasing around 2 µm.
Publisher: Springer Science and Business Media LLC
Date: 24-05-2021
DOI: 10.1038/S41598-021-90249-9
Abstract: To support the growing landscape of near to mid-IR laser applications we demonstrate a range of low propagation loss femtosecond laser (FSL) written waveguides (WGs) that have achieved guided-mode laser operation in a rare earth (RE) doped lead-germanate glass. The WGs are fabricated in both the athermal and thermal FSL writing regimes using three different pulse repetition frequencies (PRF): 100 kHz (athermal) 1 MHz and 5 MHz (thermal). The lasing capability of Yb 3+ doped lead-germanate waveguides is verified in the near-IR. The refractive index contrast (∆n) for 100 kHz WGs is ~ 1 × 10 –4 , while for 5 MHz, ∆n increases to ~ 5 × 10 –4 . The WGs in the thermal regime are less effected by self-focusing and are larger in dimensions with reduced propagation losses. For the 1 MHz repetition rate thermal writing regime we report a low propagation loss WG (0.2 dB/cm) and demonstrate laser operation with slope efficiencies of up to ~ 28%.
No related grants have been discovered for Mamoona Khalid.