Innovative and manufacturable approaches to exploiting low cost-per-Watt diode-laser pumping of Ti:sapphire

Summary of Project:

Titanium sapphire lasers are an enabling scientific and industrial tool across applications from biological imaging to quantum technologies. They are also a vital and growing part of Glasgow’s hi-tech economy and the wider photonics industry cluster. The studentship will build on recent Strathclyde work on novel Ti:sapphire crystal specifications to progress towards multi-Watt lasers that combine the low-cost per Watt and reliability of diode laser pumping with designs that are more suited to volume manufacture.

Details of Project:

Titanium sapphire (Ti:sapphire) lasers are an enabling scientific and industrial tool across applications from biological imaging to quantum technologies. They are also a vital and growing part of Glasgow’s hi-tech economy, with the city being home to two of the world’s leading manufacturers of these high-value lasers.

 These lasers provide precision performance – ultrashort pulses, or tuneable narrow linewidths – with a flexibility that is unmatched by any other laser type, leading to them becoming the engine of biomedical microscopy and ultrafast spectroscopy. However, these lasers are bulky, expensive, and generally lab-bound. Much of this cost and bulk comes from the requirement for a sophisticated and expensive pump laser to pump the Ti:sapphire laser. Conventional pump lasers for Ti:sapphire are complex diode-laser-pumped solid-state lasers in the infra-red that are then intracavity frequency doubled into the green.

 Strathclyde were the first to demonstrate pumping of Ti:sapphire lasers with simple and cheap diode lasers [1] – potentially reducing the footprint and cost of the complete Ti:sapphire laser system by at least a factor of two. Recently [2], we have shown that by making an unconventional choice of crystal specification, we can increase the output power of diode-pumped Ti:sapphire lasers to the Watt-level when pumping with only two blue laser diodes, reaching the power requirement for many mid-market Ti:sapphire laser applications at a pump laser cost two orders of magnitude lower than the current state of the art for commercial systems.

 Until now, diode-pumped Ti:sapphire lasers have used design strategies inherited from their conventionally pumped counterparts. However, such approaches are ill-equipped to fully exploit the potential of diode-laser pumping to make Ti:sapphire lasers less expensive and more manufacturable. In particular they are ill-designed for dealing with the poor beam quality of the output from high-power diode lasers and they are unsuited to low-cost manufacture of the Ti:sapphire laser itself. Conventional Ti:sapphire lasers require the painstaking and highly skilled hand-build of two high-performance lasers: the pump laser and the Ti:sapphire laser itself. Diode-pumping means the pump laser is mass-producible; this project aims to significantly simplify the design of the Ti:sapphire laser itself and make it amenable to volume manufacture.

 The studentship will build on recent Strathclyde work to progress towards multi-Watt lasers that combine the low-cost per Watt and reliability of diode laser pumping with designs that are more suited to volume manufacture.

Institute of Photonics: The Institute of Photonics (IoP), part of the Department of Physics, is a centre of excellence in applications-oriented research at the University of Strathclyde. The Institute’s key objective is to bridge the gap between academic research and industrial applications and development in the area of photonics. The IoP is located in the £100M Technology and Innovation Centre on Strathclyde’s Glasgow city centre campus, at the heart of Glasgow’s Innovation District, where it is co-located with the UK’s first Fraunhofer Research Centre. Researchers at the IoP are active in a broad range of photonics fields under the areas of Photonic Devices, Advanced Lasers and Neurophotonics, please see: http://www.strath.ac.uk/science/physics/instituteofphotonics/ourresearch/.

 Strathclyde Physics is a member of SUPA, the Scottish Universities Physics Alliance.

 The University of Strathclyde has, in recent years, been the recipient of the following awards: The Queen’s Anniversary Prizes for Higher and Further Education 2019, 2021 & 2023; Times Higher Education University of the Year 2012 & 2019; Daily Mail University of the Year 2024 Runner-Up; Daily Mail Scottish University of the Year 2024; Triple E European Entrepreneurial University of the Year 2023.

Student eligibility:

To enter our PhD programme applicants require an upper-second or first class BSc Honours degree, or a Masters qualification of equal or higher standard, in Physics, Engineering or a related discipline. Full funding, covering fees and stipend, is available for applicants who are UK Nationals (meeting residency requirements) or have settled status (meeting residency requirements), pre-settled status or otherwise have indefinite leave to remain or enter.